Acier inoxidable 17-4PH

17-4PH is a martensitic precipitation-hardening stainless steel that provides an outstanding combination of high strength and the corrosion resistance of stainless steels. The strength, corrosion resistance and easy fabrication make 17-4PH a cost effective replacement for high strength carbon steels as well as other stainless steels.

Chemical Composition (wt. %)

Main Features

1. Corrosion resistant.
2. High tensile strength and hardness up to 600°F
3. Good machinability and excellent welding characteristics.
4. The combination of excellent mechanical and processing properties.

Main Applications

1. Used where high strength and good corrosion resistance are required.
2. Applications requiring high fatigue strength, good resistance to galling, seizing, and stress corrosion.
3. Suitable for intricate parts requiring machining and welding.
4. 17-4PH are widely used in the aerospace, chemical, petrochemical, food processing, paper and general metalworking.

Fabrication

17-4PH can be easily welded and processed by standard shop fabrication practices.

Hot forming

Hot working of 17-4PH should be performed at 950 -1200°C (1742 — 2192°F). After hot working, full heat treatment is required. This involves annealing and cooling to room temperature or lower. Then the component needs to be precipitation hardened to achieve the required mechanical properties.

Cold forming

Cold forming such as rolling, bending and hydroforming can be performed on 17-4PH, but only in the fully annealed condition. After cold working, stress corrosion resistance is improved by re-ageing at the precipitation hardening temperature.

Welding

Precipitation hardening 17-4PH can be readily welded using procedures similar to those used for the 300 series of stainless steels. Welding up to 100mm thick can be carried out without the requirement of pre heating due to its low hardness.

Acier inoxidable 304/304H

304/304H is an economical and versatile corrosion resistant stainless steel suitable for a wide range of general purpose applications. 304H is a modification of 304 with carbon content controlled in the range of 0.04 to 0.10 for increased strength at temperatures above about 800°F. 304/304H is non-magnetic in the annealed condition

Chemical Composition (wt. %)

Note: for 304, C: 0.08% max.

Main Features

1. A versatile, general purpose stainless.
2. Good resistance to atmospheric corrosion, to many organic and inorganic chemicals, and to foods and beverages.
3. Service temperature can be up to about 1500°F.

Main Applications

1. pressure vessels.
2. Petrochemical equipment.

Fabrication and Heat Treatment

Cold working: 304/304H is readily formed and fabricated through a full range of cold working operations. Any cold working operations will increase the strength and hardness of the material, and may leave it slightly magnetic.

Hot working: 304/304H can be forged in the 1700-2200°F range. For maximum corrosion resistance, forgings should be annealed at 1900°F minimum and water quenched or rapidly cooled by other means after hot working operations.

Machinability: 304/304H is a tough austenitic stainless steel subject to work hardening during deformation. The best machining results are achieved with slower speeds, heavier feeds, excellent lubrication, sharp tooling, and powerful, rigid equipment.

Heat treatment: Annealing — 304/304H should be heated to 1900ºF minimum and water quenched or rapidly cooled by other means. Hardening — 304/304H cannot be hardened by heat treatment.

Welding

304/304H is readily welded by a full range of conventional welding procedures except oxyacetylene. After welding 304/304H may be necessary to fully anneal to restore the corrosion resistance lost by sensitization to intergranular corrosion when chromium carbides were precipitated in the grain boundaries in the weld heat-affected zone.

Acier inoxidable 304L

304L is a modification of 304 with a lower carbon content (0.030max) for better intergranular resistance than 304. 304L is non-magnetic in the annealed condition. It is an economical and versatile corrosion resistant stainless steel suitable for a wide range of general purpose applications.

Chemical Composition (wt. %)

Main Features

1. A versatile, general purpose stainless.
2. Good resistance to atmospheric corrosion, to many organic and inorganic chemicals, and to foods and beverages.

Main Applications

1. pressure vessels.
2. Petrochemical equipment.

Fabrication and Heat Treatment

Cold working: 304L is readily formed and fabricated through a full range of cold working operations. Any cold working operations will increase the strength and hardness of the material, and may leave it slightly magnetic.

Hot working: 304L can be forged in the 1700-2200°F range. For maximum corrosion resistance, forgings should be annealed at 1900°F minimum and water quenched or rapidly cooled by other means after hot working operations.

Machinability: 304L is a tough austenitic stainless steel subject to work hardening during deformation. The best machining results are achieved with slower speeds, heavier feeds, excellent lubrication, sharp tooling, and powerful, rigid equipment.

Heat treatment: Annealing — 304L should be heated to 1900ºF minimum and water quenched or rapidly cooled by other means. Hardening — 304L cannot be hardened by heat treatment.

Welding

304L is readily welded by a full range of conventional welding procedures except oxyacetylene. After welding 304L may be necessary to fully anneal to restore the corrosion resistance lost by sensitization to intergranular corrosion when chromium carbides were precipitated in the grain boundaries in the weld heat-affected zone.

Acier inoxidable 309

309 is an austenitic stainless steel typically used for elevated temperature applications. Its high chromium and nickel contents provide comparable corrosion resistance, superior resistance to oxidation, and the retention of a larger fraction of room temperature strength than the common austenitic 304.

Chemical Composition (wt. %)

Main Features

1. Good oxidation resistant up to 1900°F.
2. Moderate strength at elevated temperature.
3. Good resistant to high temperature sulfur bearing atmospheres.
4. Easy to be fabricated and good weldability.

Main Applications

1. Quality standard for furnaces and other high temperature components.
2. Compared to other grades for applications and due to the high tensile strength at elevated temperatures, 309 is ideal for application where special emphasis is placed on mechanical properties.

Fabrication

309 can be easily welded and processed by standard shop fabrication practices.

Hot forming

Heat uniformly at 1742 – 2192°F (950 – 1200°C). After hot forming a final anneal at 1832 – 2101°F (1000 – 1150°C) followed by rapid quenching is recommended.

Cold forming

The alloy is quite ductile and forms in a manner very similar to 316. Cold forming of pieces with long-term exposure to high temperatures is not recommended since the alloy is subject to carbide precipitation and sigma phase precipitants.

Welding

309 can be readily welded by most standard processes including TIG, PLASMA, MIG, SMAW, SAW and FCAW.

Acier inoxidable 310

310 is an austenitic stainless steel developed for use in high temperature corrosion resistant applications. The alloy resists oxidation up to 2000°F (1100°C) under mildly cyclic conditions.

Chemical Composition (wt. %)

Main Features

1. High resistance to oxidation, and may be used in continuous service up to 2000ºF (1100ºC) provided reducing sulphur gases are not present.
2. High strength and creep properties at elevated temperatures.
3. Good resistance to hot corrosion.
4. Good strength and toughness at cryogenic temperature.

Main Applications

1. High temperature application: Furnaces — radiant tubes, burners, doors, fans, piping; Fluidized Bed Furnaces — coal combustors, grids, piping, wind boxes; Thermal Processing — annealing covers and boxes, burner grids, doors, fans, muffles and retorts, recuperators, walking beams; Cement Plants –burners, burner shields, feeding and discharging systems.
2. Cryogenic structures.
3. Food processing equipment.
4. Smelter and steel melting equipment, continuous casting equipment.
5. Petroleum refining equipment.
6. Power generation — coal gasifier internals, pulverized coal burners, tube hangers.

Fabrication

310 can be easily welded and processed by standard shop fabrication practices.

Hot forming

Heat uniformly at 1742 – 2192°F (950 – 1200°C). After hot forming a final anneal at 1832 – 2101°F (1000 – 1150°C) followed by rapid quenching is recommended.

Cold forming

The alloy is quite ductile and forms in a manner very similar to 316. Cold forming of pieces with long-term exposure to high temperatures is not recommended since the alloy is subject to carbide precipitation and sigma phase precipitants.

Welding

310 can be readily welded by most standard processes including TIG, PLASMA, MIG, SMAW, SAW and FCAW

Acier inoxidable 316/316L

316/316L is one of the most commonly used austenitic stainless steel in the chemical process industry. The addition of molybdenum increases general corrosion resistance, improves chloride pitting resistance to 304/304L.

Chemical Composition (wt. %)

Main Features

1. Improved general corrosion resistance to 304/304L.
2. Improved chloride pitting and crevice resistance to 304/304l due to the addition of Mo.
3. Good formability and weldability.

Main Applications

1. Chemical process vessels.
2. Pulp & paper production equipment.
3. Pharmaceutical and medical equipment.
4. Food processing.
5. Marine industry.

Fabrication and Heat Treatment

Cold working: 316/316L is readily formed and fabricated through a full range of cold working operations. Any cold working operations will increase the strength and hardness of the material.

Hot working: 316/316L can be forged in the 1700-2200°F range. For maximum corrosion resistance, forgings should be annealed at 1900°F minimum and water quenched or rapidly cooled by other means after hot working operations.

Machinability: 316/316L is a tough austenitic stainless steel subject to work hardening during deformation. The best machining results are achieved with slower speeds, heavier feeds, excellent lubrication, sharp tooling, and powerful, rigid equipment.

Heat treatment: Annealing — 316/316L should be heated to 1900ºF minimum and water quenched or rapidly cooled by other means. Hardening — 316/316L cannot be hardened by heat treatment.

Welding

316/316L is readily welded by a full range of conventional welding procedures except oxyacetylene. After welding 316/316L may be necessary to fully anneal to restore the corrosion resistance lost by sensitization to intergranular corrosion when chromium carbides were precipitated in the grain boundaries in the weld heat-affected zone.

Acier inoxidable 317L

317L is a molybdenum containing austenitic stainless steel, with improved corrosion resistance over 316/316L in highly corrosive process environments, particularly those containing chlorides or other halides through increasing the levels of chromium, nickel and molybdenum.

Chemical Composition (wt. %)

Main Features

1. Excellent corrosion resistance in a wide range of chemicals, especially in acidic chloride environments.
2. Improved general and localized corrosion resistance to 316/316L.
3. Good formability and weldability.

Main Applications

1. Chemical process vessels.
2. Pulp & paper production equipment.
3. Condensers in power generation.
4. FGD systems.
5. Petrochemical equipments..

Fabrication and Heat Treatment

Cold working: 317L is readily formed and fabricated through a full range of cold working operations. Any cold working operations will increase the strength and hardness of the material.

Hot working: 317L can be forged in the 1700-2200°F range. For maximum corrosion resistance, forgings should be annealed at 1900°F minimum and water quenched or rapidly cooled by other means after hot working operations.

Machinability: 317L is a tough austenitic stainless steel subject to work hardening during deformation. The best machining results are achieved with slower speeds, heavier feeds, excellent lubrication, sharp tooling, and powerful, rigid equipment.

Heat treatment: Annealing — 317L should be heated to 1900ºF minimum and water quenched or rapidly cooled by other means. Hardening — 317L cannot be hardened by heat treatment.

Welding

317L is readily welded by a full range of conventional welding procedures except oxyacetylene. After welding 317L may be necessary to fully anneal to restore the corrosion resistance lost by sensitization to intergranular corrosion when chromium carbides were precipitated in the grain boundaries in the weld heat-affected zone.

Acier inoxidable 321

321 is a titanium stabilized austenitic stainless steel with an excellent resistance to intergranular corrosion being exposed to the temperatures in the chromium carbide precipitation range from 800 to 1500°F (427 to 816°C). Its another advantageous is for high temperature service due to its good mechanical properties at elevated temperatures. It has higher creep and stress rupture properties than 304.

Chemical Composition (wt. %)

Main Features

1. Good oxidation resistant up to 1600°F.
2. Good resistance to intergranular corrosion.
3. Better high temperature properties than 304.
4. May be susceptible to chloride stress cracking.
5. Easy to be fabricated and good weldability.

Main Applications

1. Aircraft piston engine manifolds.
2. High temperature chemical processing equipment.
3. Expansion joints.
4. Food processing equipment and storage.
5. Petroleum refinery equipment.

Fabrication

321 can be easily welded and processed by standard shop fabrication methods.

Hot forming

Heat uniformly at 2100 – 2300°F (1149 – 1260°C) for hot forming. Hot forming 347at temperatures below 1700°F (927°C) is not recommended. This alloy should be water quenched or fully annealed after hot working to re-attain maximum corrosion resistance.

Cold forming

The alloy is quite ductile and forms easily.

Welding

321 can be readily welded by most standard processes including TIG, PLASMA, MIG, SMAW, SAW and FCAW. No heat treatment is needed after welding.

Acier inoxidable 347

347 is a columbium stabilized austenitic stainless steel with good general corrosion resistance and better resistance in strong oxidizing conditions than 321. It shows excellent resistance to intergranular corrosion after be exposed to the temperatures in the chromium carbide precipitation range of 800 – 1500°F (427 – 816°C). The alloy has good oxidation resistance and creep strength to 1500°F (816°C). It also possesses good low temperature toughness.

Chemical Composition (wt. %)

Main Features

1. Good oxidation resistance and creep strength to 1500°F (816°C).
2. Good resistance to intergranular corrosion.
3. Good low temperature toughness.
4. Easy to be fabricated and good weldability.

Main Applications

1. Waste heat recovery.
2. High temperature chemical processing equipment.
3. Fluid catalytic cracking units, polythionic acid service.
4. Food processing equipment and storage.
5. Petroleum refinery equipment.

Fabrication

347 can be easily welded and processed by standard shop fabrication methods.

Hot forming

Heat uniformly at 2100 – 2250°F (1149 – 1232°C) for hot forming. Hot forming 347at temperatures below 1700°F (927°C) is not recommended. This alloy should be water quenched or fully annealed after hot working to re-attain maximum corrosion resistance.

Cold forming

The alloy is quite ductile and forms easily.

Welding

347 can be readily welded by most standard processes including TIG, PLASMA, MIG, SMAW, SAW and FCAW. Heat treatment is not needed after welding.

Acier inoxidable 409

409 is a ferritic stabilized stainless steel, especially useful for the applications where oxidation or corrosion protection beyond the capacity of carbon steel and some coated steels. It is magnetic, and has good ductility, easily fabricated.

Chemical Composition (wt. %)

Main Features

1. Good corrosion resistance in moderate corrosive environment.
2. Good oxidation resistant up to 1450°F (789°C).
3. Not susceptible to chloride induced stress corrosion cracking.
4. Good ductility, easy for fabrication.

Main Applications

1. Automotive exhaust system parts: mufflers, pipes, catalytic converters, support parts.
2. Other applications at elevated temperatures, such as gas turbine exhaust silencers, heat exchangers.

Fabrication

409 stainless provides good fabricating characteristics and can be cut, blanked and formed without difficulties. Stainless steels provide fabricating characteristics that are much improved when compared to 409 stainless steel. Brakes and presses used normally on carbon steel can be used on 409 stainless.

Welding

1. Conventional welding methods and filler materials applied to austenitic 300 series can be used.
2. Titanium stabilized to be resistant against sensitization in Heat Affected Zone (HAZ).
3. Shielding gases should be based on Ar/He, mixed with some oxygen to improve arc stability. Hydrogen and nitrogen must not be used.
4. Heat input in welding should been kept in a minimum level.

Acier inoxidable 6% Moly (254SMo)

254SMo is a high-alloy austenitic stainless steel. Similar to alloy 904L, but with increased molybdenum and nitrogen contents, to be used in seawater, oil and gas piping systems on offshore production platforms and other aggressive chloride bearing media. With a excellent resistant to pitting, crevice corrosion and to stress-corrosion cracking.

Chemical Composition (wt. %)

Main Features

1. Excellent resistance to pitting and crevice corrosion.
2. High resistance to general corrosion.
3. High resistance to stress corrosion cracking.
4. High strength than conventional austenitic stainless steel.
5. Good weldability.

Main Applications

1. Process equipment in chemical industry.
2. Bleaching equipment in the pulp and paper industry.
3. Offshore production platforms and other aggressive chloride bearing media.
4. FGD systems.
5. Desalination and seawater handling equipment.

Fabrication and Heat Treatment

254SMo can be readily formed using various cold and hot working processes. Details to see « FABRICATION INSTRUCTIONS FOR HIGH-ALLOYED AUSTENITIC STEELS AND NICKEL ALLOYS »

Welding

254SMo can be joined to itself and to many other metals by conventional welding processes. These include GTAW (TIG), plasma arc, GMAW (MIG/MAG) and SMAW (MMA). Pulsed arc welding is the preferred technique. For welding, 254SMo should be in the soft-annealed or stress relieved condition and be free from scale, grease and markings.

Acier inoxidable 904L

904L is a low carbon high alloy austenitic stainless steel. The addition of copper to 904L gives it greatly improved resistance to strong reducing acids, particularly sulphuric acid. It is also highly resistant to chloride attack in pitting, crevice corrosion and stress corrosion cracking.

Chemical Composition (wt. %)

Main Features

1. Good resistance to chloride stress corrosion cracking.
2. Good crevice corrosion resistant over 316L and 317L.
3. Good weldability and excellent formability.

Main Applications

1. Process equipment in chemical industry.
2. Bleaching equipment in the pulp and paper industry.
3. FGD systems.
4. Desalination and seawater handling equipment.
5. Food and beverage.
6. Pharmaceutical equipment.

Fabrication and Heat Treatment

904L can be readily formed using various cold and hot working processes. Details to see « FABRICATION INSTRUCTIONS FOR HIGH-ALLOYED AUSTENITIC STEELS AND NICKEL ALLOYS »

Welding

904L can be joined to itself and to many other metals by conventional welding processes. These include GTAW (TIG), plasma arc, GMAW (MIG/MAG) and SMAW (MMA). Pulsed arc welding is the preferred technique.
For welding, 904L should be in the soft-annealed or stress relieved condition and be free from scale, grease and markings.