Our company supplies AISI 304 stainless steel in the form of pipes, fittings, sheets and sections. Sale of stainless steel is carried out from a warehouse or on order, wholesale and retail. We cooperate with leading foreign manufacturers and are ready to offer many standard sizes of high-quality products. The range of services provided includes grinding, perforation, longitudinal and transverse cutting of metal (cut to size). At the request of the customer, packaging and delivery of goods in Moscow, the region or the regions is carried out.
AISI 304 stainless steel pipe has a round, square or rectangular section. Depending on the production method, we sell electric-welded and seamless pipes. Surface of a stainless steel: opaque, polished, mirror. Diameter: 6-406.4 mm. Profile width: 10-30 mm. Wall thickness: 1-4 mm. The AISI 304 pipe is used for the manufacture of prefabricated and welded structures, elements of pipeline fittings and household equipment. For example, balcony and stair railings, parts of kitchen and oven equipment, muffles and exhaust systems. For long-term operation in an oxidizing environment, the more expensive AISI 316 steel is better suited. It reliably resists the effects of moisture and chemicals when finishing the facades of buildings or swimming pools.
AISI 304 stainless steel sheet according to the production method is divided into cold rolled and hot rolled. Deliveries of flat rolled metal products are carried out in sheets or rolls. Stainless steel texture: smooth, embossed, decorative and perforated. Surface of a cloth: opaque, polished, mirror. Thickness: 0.5-20mm. Cutting options: 1000x2000, 1250x2500, 1500x3000, 1500x6000 mm. AISI 304 sheet is used for the production of electric welded pipes, cutting tools, building structures and equipment. It is entirely made of stainless steel and does not corrode in places of scratches or other mechanical damage. The tanks obtained from it are suitable for storage and transportation. food products, weak chemical reagents.
Long products AISI 304 contains a stainless steel circle, square, hexagon, angle and strip. The proposed stainless steel differs in the shape of the cross section. A wide range of sizes allows you to choose the right products for solving various problems.
| Beam stainless AISI 304 (08X18H10) | Size 80x46-400x180 mm, wall thickness 3.8-8.6 mm, price from 750 rubles/kg |
| Square stainless steel AISI 304 (08X18H10) | Side 4-50 mm, calibrated, matte, price from 236 rubles/kg |
| Circle corrosion-proof AISI 304 (08X18H10) | Diameter 3-100 mm, calibrated, matte, price from 200 rubles/kg |
| Tape stainless AISI 304 (08X18H10) | Thickness 0.8 mm, width 20 mm, cold-rolled, mounting, winding 25, 50 and 75 m, price - specify |
| Stainless steel sheet AISI 304 (08X18H10) | Thickness 0.4-30 mm, cold-coloured and hot-rolled, matte, polished, mirror, decorative, corrugated, perforated, price from 176 rubles/kg |
| Strip stainless AISI 304 (08X18H10) | Thickness 3-20 mm, width 10-100 mm, hot-smoked, calibrated, matte, ground and polished, price from 230 rubles/kg |
| Stainless roll AISI 304 (08X18H10) | |
| Taurus stainless AISI 304 (08X18H10) | Size 20x20-100x100 mm, wall thickness 3-10 mm, hot-smoked, price from 499 rubles/kg |
| Pipe stainless AISI 304 (08X18H10) | Diameter 6-406.4 mm, wall thickness 1-5 mm, length 6 m, e / s, matte, polished and mirror, price from 184 rubles / kg |
| Corner stainless AISI 304 (08X18H10) | Size 20x20-150x150 mm, wall thickness 1.5-12 mm, hot-rolled and bent, matte, polished and mirror, price from 210 rubles / kg |
| Channel stainless AISI 304 (08X18H10) | Size 20x10-300x100 mm, wall thickness 2-10 mm, hot-rolled and welded, price from 450 rubles/kg |
| Hexagon stainless AISI 304 (08X18H10) | Size 6-50 mm, calibrated, matt, price from 228 rubles/kg |
| Stainless steel strip AISI 304 (08X18H10) | Thickness 0.5-4 mm, cold-coloured, matte, polished and mirror, price - specify |
Sizes and cost of goods are constantly updated, so please contact our managers to quickly and correctly place your order.
Material characteristics
AISI 304 is the most common austenitic stainless steel grade. The letter marking indicates the standard used, the numbers indicate the category and features of the steel. Chemical composition in %: Cr (18-20), Ni (8-11), C (0.8), Si (1), Mn (2), P (0.045) and S (0.03). The material is not magnetic. The domestic analogue is stainless steel 08X18H10. The first digits indicate the percentage of carbon, and subsequent letters and numbers correspond to the main alloying elements.
AISI 304 steel is hardened by adding nitrogen or heat treatment in factory conditions. Alloying with titanium and carbon improves the heat resistance of steel. A significant content of nickel and chromium ensures the operational durability of the material.
AISI 304 steel is easy to weld, resistant to oxidation, low and high temperatures, has increased strength, ductility and elasticity. Due to its unique properties and affordable cost, it has found wide application in construction, mechanical engineering, chemical, food, light and mining industries.
304L is widely used in manufacturing various kinds rolled metal - stainless pipes, angles, sheets, tapes, hexagons, circles, etc. are made from it. The increased demand for stainless steel AISI 304, 304L is due to its versatility, excellent mechanical properties and chemical composition, as well as a number of others. distinctive features, among which:
- excellent weldability;
- good resistance to oxidation;
- excellent anti-corrosion properties;
- resistance to sudden changes in temperature and other climatic influences;
- affordable price.
AISI 304 and AISI 304L analogues
Russian analogues of AISI 304 are steel grades 08X18H10 and 03X18H11 (according to GOST).
Scope of stainless steel AISI 304, 304L.
AISI 304 stainless steel is used in many areas of human activity, and its excellent temperature resistance and anti-corrosion properties are the main advantages over other steel grades. We list only some areas of application of AISI 304, 304L stainless steel:
- Various industries where steel is used in the manufacture of rolled metal products and metal structures.
- Reservoirs and containers, as well as pipes for storing and transporting various types of liquids, including drinking water.
Differentiation of steel grade 304 AISI
Depending on the application and the need for further processing in the production of AISI 304, 304L, Deco stainless steel, it can be manufactured in accordance with certain properties, for example:
- stainless steel strength, heat resistance;
- quality of weldability and subsequent machining;
- deep and rotary extract;
- stretch molding, etc.
Steel AISI 304 chemical composition (ASTM A240)
| Ni | Cr | Si | S | P | Mn | C | |
| 304L AISI | 8.0 - 12.0 | 18.0 to 20.0 | max | max | max | max | 0.03max |
| 304 AISI | 8.0 to 10.50 | 18.0 to 20.0 | 1.0 | 0.030 | 0.045 | 2.0 | 0.08max |
Mechanical properties at room temperature
| 304L AISI | 304 AISI | |||
| Typical | Min | Typical | Min | |
| Fatigue strength, N/mm2 | 240 | - | 240 | - |
| A5 | 60 | 40 | 60 | 40 |
| relative extension, % | ||||
| Brinell hardness - HB | 170 | - | 170 | - |
| Rp m | 590 | 485 | 600 | 515 |
| Rp0.2 | 310 | 170 | 310 | 205 |
| Elastic Limit, (0.2%), (yield), N/mm2 | ||||
To improve the mechanical properties of stainless steel, in particular its strength, it is necessary:
- increase the nitrogen content in steel;
- use repeated skin-pass rolling, which significantly strengthens the steel.
Nitrogen-rich stainless steel is most commonly used in shipping containers, large tanks and other steel structures where high design strength with minimum wall thickness is required. Very often, austenitic steel, which is characterized by increased strength, is used in the production of welded stainless pipes, molding plates, supporting elements of metal structures, chains, strips, etc.
Properties of stainless steel AISI 304 at high temperatures
All values given in this table apply only to stainless steel AISI 304. The strength of steel grades 304L, Deco at high temperatures differs significantly (at temperatures above +425 ° C).
| Rp m | 380 | 270 | 170 | 90 | 50 |
| Tensile strength (tensile), N/mm2 | |||||
| Temperature, °C | 600 | 700 | 800 | 900 | 1000 |
Minimum values of elastic limit at high temperature
| Rp1.0 | 120 | 80 | 50 | 30 | 10 |
| 1.0% plastic deformation (yield), N/mm2 | |||||
| Temperature, °C | 550 | 600 | 650 | 700 | 800 |
- Continuous exposure to +925 °C.
- Intermittent exposure +850 °C.
Properties of stainless steel 304 AISI, 304L AISI at low temperatures
| Temperature, °C | Rp m | Tensile strength (tensile), N/mm2 | Rp0.2 | Elasticity Limit, (0.2%), (conditional yield stress), N/mm2 | Impact strength, J |
| -78 | 1100/950 | 300/180 | 180/175 | ||
| -161 | 1450/1200 | 380/220 | 160/160 | ||
| -196 | 1600/1350 | 400/220 | 155/150 | ||
Corrosion resistance
Acid environments
The table shows only general values for the resistance of stainless steel to various types of acids. The exact resistance values depend on the specific properties of the steel.
| Temperature, °C | Concentration, % by weight | Sulphuric acid | Nitric acid | Phosphoric acid | Formic acid |
| 20 | 10 | 2 | 0 | 0 | 0 |
| 20 | 2 | 0 | 0 | 0 | |
| 40 | 2 | 0 | 0 | 0 | |
| 60 | 2 | 0 | 0 | 0 | |
| 80 | 1 | 2 | 0 | 0 | |
| 100 | 0 | 0 | 2 | 0 | |
| 80 | 10 | 2 | 0 | 0 | 0 |
| 20 | 2 | 0 | 0 | 1 | |
| 40 | 2 | 0 | 0 | 2 | |
| 60 | 2 | 0 | 0 | 2 | |
| 80 | 2 | 1 | 1 | 1 | |
| 100 | 2 | 2 | 2 | 0 |
Code: 0 = high degree of protection (corrosion rate does not exceed 100 mm/year); 1 = partial protection (corrosion rate is between 100m and 1000 mm/year); 2 = non resistant - (corrosion rate exceeds 1000 mm/year).
Atmospheric influences
The table shows the corrosion values for AISI 304 stainless steel, as well as a comparison with other metals under similar atmospheric conditions for certain period time (at this case indicators are specified at atmospheric influences for 10 years).
| Environment | rural | Maritime | Industrial Marine | |
| Corrosion rate (mm/year) | AISI 304 | 0.0025 | 0.0076 | 0.0076 |
| Aluminum-3S | 0.025 | 0.432 | 0.686 | |
| carbon steel | 05.aug | 34.0 | 46.2 | |
Heat treatment of stainless steel:
Annealing.
Annealing of stainless steel, to ensure good anti-corrosion properties, is carried out at high temperatures - from +1010 °C to +1120 °C, after which the steel is rapidly cooled by rapid tempering in water or air. The optimum firing temperature for maximum corrosion resistance is +1070 °C.
Vacation (stress relief).
Stress relief for stainless steel grade 304L AISI is carried out for one hour at temperatures from +450 to +600 °C. The minimum tempering temperature should not drop to +400 °C.
Hot working (forging interval).
Hot working of stainless steel should be carried out at a temperature of +1150–1260 °C and end with temperatures in the range of +900 to +925 °C. Annealing of stainless steel when performing hot working is mandatory. When hot working stainless steel, it is important to remember that it takes significantly longer to heat it uniformly to the desired temperature than carbon steels.
Cold working stainless steel:
Stainless steel grades 304 AISI and 304L AISI is very popular in many areas of industry, construction and other areas of human activity due to its increased strength, ductility and elasticity.
There are several types of cold working of stainless steel - deep and rotary drawing, forming, stretching and bending.
Stainless steel can be formed using machines and tools that are used for carbon steel, but it is important to remember that such steel has an increased degree of hardening, so much more force is required.
AISI 304 stainless steel bending.
The bending limits of stainless steel sheets depend on the thickness of the sheets (S) and bending radius (R):
- S< 3мм, мин. R = 0;
- 3mm< S < 6мм, мин. R = 0,5·S, угол гибки 180°;
- 6mm< S < 12мм, мин. R = 0.5·S, угол гибки 90°.
When bending stainless steel, it is important to remember that the back straightening of such sheets is substantially greater than that of carbon steel sheets. Below you can find the approximate values of reverse straightening when bending sheets to a right angle.
- R = S back straightening approx. 2°;
- R = 6 S back straightening approx. 4°;
- R = 20 S back straightening approx. 15°.
When bending austenitic stainless steel, the minimum bending radius should be equal to the thickness of the sheets multiplied by two or more (R = S x 2). If bending of ferritic stainless steel is expected, then the minimum bending values should be:
- S< 6 мм, - мин R = S, 180°;
- 6 < S < 12мм, - мин R = S, 90°.
Stretch moulding.
When performing tensile forming, the workpiece of the future stainless steel product is subjected to the so-called "braking", which occurs for the entire time of drawing.
Since the walls of the product become very thin during this procedure, in order to avoid their ruptures, it is necessary to foresee the properties of increased hardening in advance.
Deep drawing and rotary drawing.
Deep drawing implies a clean drawing without the use of "braking", although in practice this technology is not used.
Almost always in the production of stainless steel products there is a stretch forming element. To perform deep drawing, it is necessary to use only stainless steel with a minimum degree of hardening (Md 30 (N) must be in the "minus").
If deep drawing is carried out on special presses, then rotary drawing is carried out on special turning and spinning machines. In most cases, this technology is used in the production of any conical products of symmetrical rotation, for example, in the manufacture of buckets.
Stainless steel welding
One of the key characteristics of stainless steel that makes it so popular is its excellent weldability.
| welding process | Thickness without weld | Including weld | Protective environment | ||
| Thickness | Coating | ||||
| Wire | rod | ||||
| TIG | <1,5mm | >0.5mm | ER 308 l(Si) W.Nr 1.4370 | ER 308 l(Si) W.Nr 1.4370 | Argon |
| ER 347 (Si) | ER 347 (Si) | Argon + 5% Hydrogen | |||
| Argon + Helium | |||||
| resistance-spot | <2mm | ||||
| (dot)-seam (seam) | |||||
| electrode | Repairs | E 308 E 308L E 347 | |||
| S.A.W. | >2mm | ER 308 L | |||
| ER 347 | |||||
| PLASMA | <1.5mm | >0.5mm | ER 308 l(Si) W.Nr 1.4370 | ER 310 | Argon |
| ER 347 (Si) | Argon + 5% Hydrogen | ||||
| Argon + Helium | |||||
| MIG | >0.8mm | ER 308 l(Si) W.Nr 1.4370 | Argon + 2% CO 2 | ||
| ER 347 (Si) | Argon + 2% O 2 | ||||
| Argon + 3% CO 2 + 1% H 2 | |||||
| Argon + Helium | |||||
| Laser | <5mm | Helium | |||
| Sometimes Argon, Nitrogen | |||||
After welding stainless steel, no additional heat treatment is required, but it must be taken into account that at the slightest risk of intergranular corrosion, it is necessary to anneal at a temperature of +1050–1150 °C. After welding, the seam must be cleaned of scale mechanically and chemically, and subsequently passivated.
Decorative stainless steel Deco
Decorative steel of the Deco brand is a textured, polished or mirror stainless steel, which is used for exterior and interior decoration of buildings, as well as for cladding elevators, escalators, shop equipment, columns, tanks, etc.
The use of decorative steel allows you to significantly save on the purchase of other finishing materials and at the same time create an original interior or exterior design for many years to come.
Features of Deco decorative stainless steel:
- resistance to deformation;
- corrosion resistance;
- the highest strength, which is achieved by spraying with titanium nitrite;
- heat resistance;
- elasticity and ease of welding, cutting.
Corrosion resistant steel is a high-chromium steel: it is also alloyed with nickel, titanium and other impurities.
High-chromium steels are corrosion-resistant in less aggressive environments (for example, the atmosphere, salt solutions, weak acids). Grades of this steel: 1X13H3, 1X17H2, 1X11MF, etc.
Nickel-chromium alloyed with titanium, molybdenum, niobium and other impurities. It has very high corrosion resistance in any environment, including acids: concentrated sulfuric and nitric. It also belongs to high chromium with a high nickel content. The most important grades of this steel are: 0X18H11, 0X18H12T, 00X18H10, X15N9Yu, X17N13M2T, etc.
In steel grades with zero in front, the carbon content does not exceed 0.08%, and in steel grades with two zeros in front, the carbon content does not exceed 0.04%.
Applications of stainless steel in industry
| 20X13, 08X13, 12X13, 25X13H2 | For parts with increased ductility subjected to shock loads; parts operating in mildly aggressive environments. |
| 30X13, 40X13, 08X18T1 | For parts with increased hardness; cutting, measuring, surgical tools, valve plates of compressors, etc. (steel 08X18T1 has better stamping ability). |
| 06ХН28МТ | For welded structures operating in moderately aggressive environments (hot phosphoric acid, sulfuric acid up to 10%, etc.). |
| 14X17H2 | For various parts of the chemical and aviation industries. It has high technological properties. |
| 95X18 | For high hardness parts operating under wear conditions. |
| 08X17T | It is recommended as a substitute for steel 12X18H10T for structures that are not subjected to shock at an operating temperature of at least -20°C. |
| 15X25T, 15X28 | Similar to steel 08X17T, but for parts operating in more aggressive environments at temperatures from -20 to 400 ° C (15X28 - for junctions with glass). |
| 20X13N4G9, 10X14AG15, 10X14G14NZ | Substitute for steels 12X18H9, 17X18H9 for welded structures. |
| 09X15H8Yu, 07X16H6 | For high-strength products, elastic elements; steel 09X15H8YU - for acetic acid and salt media. |
| 08X17H5M3 | For parts operating in sulfuric acid environments. |
| 20X17H2 | For high-strength heavy-duty parts working on abrasion and impact in mildly aggressive environments. |
| 10H14G14N4T | Substitute for steel 12X18H10T for parts operating in slightly aggressive environments, as well as at temperatures up to 196°C. |
| 12X17G9AN4, 15X17AG14, 03X16H15MZB, 03X16H15M3 | For parts operating in atmospheric conditions (substitute for steels 12X18H9,12X18H10T) For welded structures operating in boiling phosphoric, sulfuric, 10% acetic acid. |
| 15X18H12S4TYu | For welded products operating in air and aggressive environments, in concentrated nitric acid. |
| 08X10H20T2 | Non-magnetic steel for parts operating in sea water. |
| 04X18H10, 03X18H11, 03X18H12, 08X18H10, 12X18H9, 12X18H12T, 08X18H12T, 06X18H11 | For parts operating in nitric acid at elevated temperatures. |
| 12Х18Н10Т, 12Х18Н9Т, 06ХН28MDT, 03ХН28MDT | For welded structures in various industries. For welded structures operating at temperatures up to 80 ° C in sulfuric acid of various concentrations (55% acetic and phosphoric acids are not recommended). |
| 09X16N4B | For high-strength stamp-welded structures and parts operating in contact with aggressive media. |
| 07X21G7AN5 | For welded structures operating at temperatures up to -253°C and in medium aggressive environments. |
| 03X21N21M4GB | For welded structures operating in hot phosphoric acid, low concentration sulfuric acid at temperatures not exceeding 80°C, nitric acid at temperatures up to 95°C. |
| XN65MV | For welded structures operating at high temperatures in sulfuric and hydrochloric acid solutions, in acetic acid. |
| N70MF | For welded structures operating at high temperatures in hydrochloric, sulfuric, phosphoric acids and other reducing media. |
Modern progressive technology associated with the operation of parts and mechanisms under conditions of high temperatures, gases and heavy loads is based on the use of heat resistant and scale-resistant steel and alloys. Ordinary carbon steel, when heated to 400-500 ° C, in addition to being chemically destroyed, also loses strength.
Scale resistance is the ability of a metal to resist oxidation under high temperatures and small loads.
Heat resistance is the ability of a metal to maintain strength and not oxidize under the influence of high temperatures under increased loads.
Heat resistance and scale resistance are related. Heat-resistant steel must necessarily be scale-resistant. Combustion chambers, covers for thermocouples are made of scale-resistant steel, and gas and steam turbine blades, jet engine parts are made of heat-resistant steels and alloys.
The most important alloying impurities in scale-resistant steel are aluminum, silicon, and chromium. At a content of 10-13% chromium, the steel is scale-resistant up to 750°C, at 15-17% chromium, the scale resistance increases to 800-900°C, and at 25% chromium, up to 1000°C.
In addition to steels, alloys are widely used, which, along with high scale resistance, also have high electrical resistance. These alloys are widely used in electrical engineering, since they are based not on nickel, but on iron, and therefore they are very economical. The most important of these alloys are fechral and chromal. Fechral has the following composition: 0.12% C, 4-5% Cr, 4-5% Al, the rest is Fe. Chromal contains 26% Cr, 5% Al, the rest is Fe.
Steels 15Kh11MF, 13Kh14N3V2FR, 09Kh16N15M3B and others are used for the manufacture of superheaters, steam turbine blades, and high pressure pipelines. For products operating at higher temperatures, steels 15Kh5M, 16Kh11N2V2MF, 12Kh18N12T, 37Kh12N8G8MBF, etc. are used.
Heat-resistant steels are able to resist oxidation and scale formation at temperatures of 1150 - 1250 °C. For the manufacture of steam boilers, heat exchangers, thermal furnaces, equipment operating at high temperatures in aggressive environments, steel grades 12X13, 08X18H10T, 15X25T, 10X23H18, 08X20H14C2, 1X12MVSFBR, 06X16H15M2G2TFR-ID, 12X12M1BFR-SH are used.
Heat-resistant steels are intended for the manufacture of parts that operate in a loaded state at a temperature of 600 ° C for a long time. These include: 12X1MF, 20X3MVF, 15X5VF, 12X2MFSR.
Cold resistant steel must retain its properties at temperatures of minus 40 - minus 80°C. The most widely used steels are: 20Kh2N4VA, 12KhN3A, 15KhM, 38Kh2MYuA, 30KhGSN2A, 40KhN2MA, etc.
Table of conformity EN, AISI, GOST
| Table of conformity EN, AISI, GOST | |||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Become | Chemical composition, % | ||||||||||||||||||
| EN 10088 |
AISI USA | GOST Russia |
C | Si | Mn | P | S | N | Cr | Mo | Ni | other | |||||||
| Stainless | 1.4000 | 403, 410S | 08Х13 | ~0,08 | ~1,00 | ~1,00 | ~0,040 | 12-14 | |||||||||||
| 1.4016 | 430 | 12X17 | ~0,08 | ~1,00 | ~1,00 | ~0,040 | 16-18 | ||||||||||||
| 1.4510 | 430Ti, 439 | 08Х17Т | ~0,05 | ~1,00 | ~1,00 | ~0,040 | 16-18 | ||||||||||||
| 1.4006 | 410 | 12X13, 15X13L | 0,08-0,15 | ~1,00 | ~1,50 | ~0,040 | ~0,015 | 11,5-13,5 | ~0,75 | ||||||||||
| 1.4021 | 420 | 20X13 | 0,16-0,25 | ~1,00 | ~1,50 | ~0,040 | ~0,015 | 12-14 | |||||||||||
| 1.4028 | 420F | 30X13 | 0,26-0,35 | ~1,00 | ~1,50 | ~0,040 | ~0,015 | 12-14 | |||||||||||
| 1.4057 | 431 | 20X17H2 | 0,12-0,22 | ~1,00 | ~1,50 | ~0,040 | ~0,015 | 15-17 | 1,5-2,5 | ||||||||||
| 1.4301 | 304 | 08X18H10 | ~0,07 | ~1,00 | ~2,00 | ~0,045 | ~0,015 | ~0,011 | 17-19,5 | 8-10,5 | |||||||||
| 1.4306 | 304L | 03Х18Н11 | ~0,030 | ~1,00 | ~2,00 | ~0,045 | ~0,015 | ~0,011 | 18-20 | 10-12 | |||||||||
| 1.4435 | 316L | 03Х17Н14М3 | ~0,030 | ~1,00 | ~2,00 | ~0,045 | ~0,015 | ~0,011 | 17-19 | 2,5-3 | 12,5-15 | ||||||||
| 1.4541 | 321 | 06X18H10T, 08X18H10T, 12X18H10T | ~0,08 | ~1,00 | ~2,00 | ~0,045 | ~0,015 | 17-19 | 9-12 | Ti~0.07 | |||||||||
| 1.4550 | 347, 348 | 03Х17Н14М3 | ~0,08 | ~1,00 | ~2,00 | ~0,045 | ~0,015 | 17-19 | 9-12 | Nb ~1.00 | |||||||||
| 1.4571 | 316ti | 10X17H13M2T | ~0,08 | ~1,00 | ~2,00 | ~0,045 | ~0,015 | 16,5-18,5 | 2-2,5 | 10,5-13,5 | Ti~0.07 | ||||||||
| heat resistant | 1.4828 | 309 | 20Х20Н14С2 | ~0,20 | 1,50-2 | ~2,00 | ~0,045 | ~0,030 | ~0,011 | 19-21 | 11-13 | ||||||||
| 1.4841 | 314, 310 | 20Х25Н20С2 | ~0,20 | 1,5-2,5 | ~2,00 | ~0,045 | ~0,030 | ~0,011 | 24-26 | 19-22 | |||||||||
| 1.4845 | 310S | 20X23H18 | ~0,10 | ~1,50 | ~2,00 | ~0,045 | ~0,030 | ~0,011 | 24-26 | 19-22 | |||||||||
Surface types
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APEX METAL offers customers a variety of stainless steel products made from the best grades of stainless steel that meet strict international standards and have excellent technological and operational characteristics. The high corrosion resistance of stainless steel is the main characteristic of products made from these materials for long-term operation in aggressive corrosive environments, in wide temperature ranges.
The chemical composition of rolled products made of corrosion-resistant stainless steel AISI 304 of the austenitic class meets the requirements of the AISI standard - American Iron and Steell Institute (American Institute of Steel and Alloys). In the accompanying documents, the designation of AISI stainless steel grades and its analogues is carried out in accordance with national or international standards:
| national standard | Stainless steel grade | |||
|---|---|---|---|---|
| AISI USA | AISI 304 steel | AISI 321 steel | AISI 316 steel | AISI 430 steel |
| RF standard | 08X18H10 | 12X18H10T | 08Х17Н13М2 | 12X17 |
| EN Europe | 1.4301 | 1.4541 | 1.4436 | 1.4016 |
| UNS USA | S30400 | S32100 | S31600 | S43000 |
| SIS Sweden | 2332/33 | 2337 | 2343 | 2320 |
| BS UK | 304S31 | 321S31 | 316S33 | 430S17 |
| JIS Japan | SUS304 | SUS321 | SUS316 | SUS430 |
| DIN Germany | X5CrNi18-10 | X10CrNiTi18-10 | X3CrNiMo18-3-4 | X6Cr17 |
What information can be found on the symbol of stainless steel grades
The stainless properties of steel are due to the presence of alloying elements in its composition, the main of which are chromium and nickel. To impart special properties (greater strength, cold resistance, and others), to improve technological characteristics, other alloying elements (for example, titanium, molybdenum, manganese), rare earth metal nanoadditives are added to steel.
Thanks to alloying with titanium, stainless steel 12x18n10t acquires increased cold resistance and is used for the manufacture of welded products for cryogenic equipment operating at temperatures up to -269˚С. In addition, according to the symbol of steel grades, you can determine:
- The chemical composition of steel, for example, chromium stainless steel X6Cr17 - AISI 430 contains up to 0.08% mass fraction of carbon in its composition (the number 6 after the letter X indicates the average carbon content in steel multiplied by 100) and 16 - 18% chromium
- The class of steel, for example, the number 3 in the designation of AISI 316 stainless steel, indicates that it belongs to the austenitic class. Accordingly, the number 4 in the designation of steel 430 indicates that the steel belongs to the ferritic class, the next two digits determine the serial number of steel in the group
- The European standard indicates that stainless steel belongs to a certain type, according to the serial numbers of steels 1.4301, 1.4436, 1.4016, it can be determined that the grades in question belong to the group of stainless steels (this group includes steels under the numbers 1.40XX-1.45XX)
- The letter S in the designation of steel according to the UNS standard indicates that the material belongs to the group of heat-resistant and corrosion-resistant (stainless) steels (this group includes steels designated S00001 ... S99999)
- In the designation of steel according to the Swedish standard, the numbers 23XX indicate the chromium content in steel (all grades considered in the table refer to the group of steels with a chromium content ≥10%)
- In the standards in force on the territory of the Russian Federation, on the symbol of steel can be judged on its elemental composition, the regulatory documents for stainless steel (GOST 5632 and others) provide information on the classification of steel, chemical composition, properties, purpose and applications
- In the designation of steel according to the Swedish standard, the numbers 23XX indicate chromium ≥10%)
- In the standards in force on the territory of the Russian Federation, according to the symbol of steel, one can judge its elemental
Steel grades AISI 304 and 304L (according to the American classifier ASTM A240) and their direct Russian counterparts 08X18H10 and 03X18H11 (according to GOST) are the most common and most versatile chromium-nickel high-alloy corrosion-resistant austenitic steels that are used in almost all sectors of material production, as in the CIS countries , as well as around the world. The popularity and demand for this steel is due, at a reasonable price, to its excellent resistance to oxidation and corrosion, good weldability, a unique combination of mechanical properties and chemical composition. Due to the fact that AISI 304 intergranular corrosion occurs only at high temperature heating, this grade is especially recommended for use at low and ultra-low temperatures. AISI steel is perfectly polished and retains its aesthetic appearance for a long time, which is very important in the manufacture of architectural, building and design structures, interior items and metal furniture from it.
The main areas of application of steel AISI 304
It is difficult to find a modern field of activity, where, to one degree or another, AISI 304 steel or 0818H10. From it, in particular, everywhere they make:
- containers, containers and tanks for storage and transportation of various bulk substances and liquids;
- receivers and equipment for the production and transportation of aggressive chemicals and drugs;
- parts and elements of installations for the production of liquid and pasty food products (creams, kvass, wine, milk, etc.), as well as for their transportation;
- equipment for drilling wells and strengthening mine workings;
- cooking kitchen equipment and household cutlery.
In addition, AISI 304 serves as the base material for many units of laboratory scientific instruments, cryogenic units, molding plates, support elements, etc.
Chemical composition and differentiation of AISI 304 steel
The ASTM A240 standard regulates chemical composition AISI 304 steel as follows:
- carbon - not more than 0.08% (AISI 304L - 0.03%);
- manganese - no more than 2%;
- phosphorus - no more than 0.45%;
- sulfur - no more than 0.03%;
- silicon - no more than 0.75%;
- chromium - 18.0 - 20.0%;
- nickel - 8.0 - 10.5% (AISI 304L - up to 12%);
- nitrogen - 0.1%.
The high anti-corrosion performance of AISI 304 is associated with the presence of a thin film of chromium oxide on the surface of the material. And since this steel has an absolutely uniform structure throughout its thickness, all parts and materials made from it (sheets, rods, shaped pipes, shaped blanks), even if the top layer is damaged, continue to maintain the same resistance to corrosion. The destroyed oxide film is instantly restored, preventing the spread of damage. A similar process takes place in stainless structures that are under atmospheric action. Constant temperature fluctuations lead to the appearance of microcracks, in which a protective layer is immediately formed. This property of AISI 304 steel made it possible to manufacture reliable containers, railings for external stairs and balconies, swimming pools and much more. The guaranteed durability of such products is at least 150 years.
The presence of a large amount of nickel in AISI 304 gives this steel grade an important advantage over nickel-free counterparts (AISI 430, etc.). Since the melting point of nickel is much higher than that of chromium, it remains in the metal structure even when exposed to heat (for example, during welding), while chromium almost completely burns out. Remaining in the weld, nickel provides its strength and additional corrosion resistance.
AISI 304 steel differs from many other stainless steels in the possibility of differentiation. This means that during the production process of the material, it can be given some specific properties associated with a specific area of \u200b\u200bits subsequent application or the required nature of processing. By varying the composition of steel (within the established norms), it is possible to provide it with:
- higher weldability;
- the ability to deep and rotary drawing;
- stretch forming capability;
- increased strength, work hardening;
- additional heat resistance;
- special suitability for certain types of machining.
Like any austenitic steel, AISI 304 can be, if necessary, additionally strengthened either by adding nitrogen to its composition (modification 304LN), or by one of the factory technological methods of shape strengthening (hard work, pressure, repeated skin-pass rolling or stretching).
The nitriding process is most suitable for steels intended for the manufacture of large objects in the oil and gas and chemical industries (transport containers, columns, tanks). In this case, with a higher design strength of the metal, it is possible to reduce the wall thickness and thereby achieve significant savings in material costs.
Austenitic stainless steels that have undergone form strengthening are used for the production of parts and elements that carry mechanical loads - welded pipes, molding plates for the automotive industry, keg hoops, building reinforcement, straps, chains, fences, etc.
Steel AISI 304 (08X18H10), unlike the 400th group of "stainless steel" (analogues 12X17), does not have magnetic properties, which in certain cases is very important in its practical application. However, this quality is only a consequence of the special internal structure of the metal, it in no way affects its chemical and corrosion resistance, strength characteristics and manufacturability in processing.
The most important operational properties and manufacturability of AISI 304
The main operational qualities of AISI 304 steel, which determine its applicability and manufacturability, include its following properties:
1. Resistant to high and low temperatures.
With increasing temperature, the tensile strength of AISI 304 decreases. This is especially noticeable when the material is heated above 425 degrees. C. So, if at 600 degrees. Since this parameter is equal to 380 N/mm2, then at 800 deg. C - already 170 N / mm2, and at 1000 deg. C - only 50 N/mm2. According to the same algorithm, the elastic limit also decreases.
- with continuous exposure - 925 degrees. FROM;
- with intermittent exposure - 850 degrees. FROM.
Reducing the operating temperature to ultra-low values leads to a serious increase in the strength of steel: at -78 degrees. C tensile strength is 1100 N/mm2, at -161 deg. C - 1450 N / mm2, and at -196 deg. C - 1600 N/mm2. The elastic limit of the material also slightly increases, although not to the same extent, and the impact strength deteriorates.
2. Corrosion resistance.
AISI 340 shows good resistance to most acids (with the exception of sulfuric). Under atmospheric exposure, it significantly exceeds aluminum in corrosion resistance. especially ordinary carbon steel. So, in rural conditions, the ten-year corrosion rate of AISI 340 is 0.0025 (aluminum - 0.025, carbon steel - 5.8), and in industrial marine conditions - 0.0076 (aluminum - 0.686, carbon steel - 46.2).
3. Heat treatment of the material.
- Annealing.
Optimum annealing temperature AISI 304 - from 1010 to 1120 degrees. C. The most ideal conditions for this technological operation are a temperature of 1070 degrees. C and subsequent rapid cooling (or tempering).
- Vacation.
It is best to temper steel 304 for 1 hour at a temperature of 450 to 600 degrees. C. If there is a need to avoid sensitization, the operating temperature should be reduced to 400 degrees.
- Hot working (forging).
Forging AISI 304 or its other hot processing must be carried out at an initial temperature of 1150 - 1260 degrees. C and final - 900 - 925 degrees. C. In this case, annealing of the workpiece is required. To achieve uniformity of heating, it should be taken into account that such uniformity in AISI 304 steel is achieved 12 times slower than when heating carbon steels.
4. Cold working.
AISI 304 steel and its modification 304L, due to good ductility and high strength properties, are easy to cold work. Typical types of such processing include bending, drawing (rotary and deep) and stretch forming. For the forming operation, in principle, it is possible to use the same equipment and the same tool as for carbon steels, however, since austenitic steels are additionally hardened during this process, mechanical forces one and a half to two times higher are required here.
- Bending.
Bending limits for different AISI 304 sheet thicknesses are different. With a thickness of up to 3 mm, the minimum bending radius can be practically zero, with a greater thickness - equal to half the thickness of the sheet. Bending angle - 180 degrees. with a thickness of 3 - 6 mm and 90 degrees. with a thickness of 6 - 12 mm. The reverse straightening of austenitic steels is greater than that of carbon steels. Therefore, the workpiece should be slightly “bended” (when bent at a right angle, the bend can be from 2 to 25 degrees, depending on the ratio of the radius and thickness of the sheet). The recommended minimum bending radius for 304 steel is twice the sheet thickness.
- Deep and rotary extraction.
Using a press, while deep drawing, the material is allowed to flow freely without subjecting the workpiece to braking. But when drawing products with exact dimensions, molding with stretching (braking) is most often used, in this case it is desirable to provide for a hardening process combined with molding.
Rotary drawing is carried out on turning and spinning equipment and, in fact, is molding with turning. This method usually forms products of symmetrical rotation (buckets, etc.), which do not require subsequent polishing.
5. Weldability.
AISI 304 steel can be easily welded by any modern method. Subsequent heat treatment of the seam is not required. But in order to avoid the risk of intercrystalline corrosion, it is useful to carry out additional annealing at a temperature of 1050 - 1150 degrees. C followed by rapid cooling. The cooled welding seam should be cleaned of scale and passivated (treated with pickling paste).