Wenzhou Kaixin Kaixin Metal Co., Ltd
What is TP431 rustfritt stål (OSS 43100)1.4057?
The material AISI 431, which equals 1.4057, BS 431S29, and X17CrNi16-2, is a stainless martensitic chromium-nickel steel with a chromium content of 15-17 %. Due to the high chromium content, this stainless steel has better corrosion resistance and toughness than comparable steels with a lower chromium content. The material AISI 431 (1.4057, BS 431S29, X17CrNi16-2) is magnetic (ferromagnetic) and has a tensile strength of 800-950 N/mm² (in heat treatment condition +QT800) with a density of 7.0 kg/dm³ (at room temperature). Due to its high strength and resistance, this steel is used, among other things, for the manufacture of machine parts subject to high mechanical stress, such as piston rods. The material can be used in the temperature range from -40°C to 400°C. It has good polishability, but only medium forgeability and poor machinability. Cold forming is possible. This stainless steel grade can be welded well with most welding processes.
1.4057 QT800 Stainless Steel
The exact composition varies for martensitic stainless steel grades. But typically 1.4057 stainless steel will contain: 15 - 17% krom; 2 - 2.5% Nickel; 0.12 - 0.22% Karbon. It may also have small amounts of silicon, molybden, and phosphorous. Brearley’s initial samples of stainless steel were martensitic. These alloys are magnetic and are usually formed in the annealed condition, and heat treated afterwards.
Chromium is the main alloying element of martensitic 1.4057 rustfritt stål, carrying moderate corrosion resistance to a material with inherently high strength and hardness. Normally, nickel concentrations of 2 - 2.5% are added as a stabilizing element to make sure that a martensitic steel keeps its toughness properties during heat treatment, which allows the fabrication of a number of component types.
Martensitic stainless steels are often forgotten, maybe because compared to austenitic and ferritic grades, they are not in high demand. Though, they often play a huge and often unseen role in modern infrastructure. The strength which is gained by heat treatment depends on the carbon content of the alloy. Increasing the carbon content increases the potential hardness and strength but decreases toughness and ductility.
The higher carbon grades are capable of being heat treated to a hardness up to 60 HRC. In the heat-treated, hardened and tempered condition optimum corrosion resistance is achieved. Other martensitic grades have been created with nickel and nitrogen additions but possessing lower carbon levels than the traditional grades. These steels have improved weldability, toughness, and corrosion resistance.
Equivalent Grades of Stainless Steel 1.4057
| EU I | USA – | Germany FRA,WNr | Kina GB | Poland Pn | Russia GOST |
| X17CrNi16-2 | 431 | X17CrNi16-2 | 1Cr17Ni2 ML1Cr17Ni2 | 2H17N2 | 14KH17N220KH17N2 |
1.4057 Chemical Composition
Mekaniske egenskaper
| Description | 1.4057 Rustfritt stål |
| Strekkstyrke (MPa) | <1000 |
| Yield Styrke (MPa) | 1080 |
| Forlengelse (% in 50mm) | 20 |
| Hardhet (HB) | <388 |
| Impact Charpy V (J) | 50 – 84 |
Fysiske egenskaper
Magnetizability: present
Tetthet (kg/dm³): 7.0
Termisk ledningsevne (at up to 20°C): 25
Electronic resistance at room temperature (in Ω mm²/m): 0.70
Supplied Forms
Ark;Strip;Rør;Bar;Rør;Tallerken;Beslag & Flanges;Angle.
Korrosjonsbestandighet
As a chromium-nickel steel, the material AISI 431 (1.4057, BS 431S29, X17CrNi16-2) has good corrosion resistance. Imidlertid, the material is susceptible to intergranular corrosion. Maximum corrosion resistance is achieved with a bright metallic surface.
Forgeability of the material
The martensitic chromium-nickel steel AISI 431 (1.4057, BS 431S29, X17CrNi16-2) has medium forgeability. During the forging process, the material should first be heated slowly to 850 °C. This should be followed by rapid heating. It should then be heated quickly to around 1180 °C. Forging can be carried out in the temperature range between around 1150 °C and 950 °C. The material should then cool down slowly. This material is not normally used for open-die forging and closed-die forging.
Heat Treatment
| Temperatur i °C | Cooling | |
| Hot forming | 1.100 – 800 | Furnace, slow cooling |
| Heat treatment | ||
| Soft annealing (+ EN) | 680 – 800 | Furnace, air |
| Tempering (+ QT) | ||
| Herding | 950 – 1050 | Oil, air or polymer |
| Annealing QT800 | 750 – 800 + 650 – 700 | Water or air |
| Annealing QT900 | 600 – 650 | Water or air |
Cold forming
The material 1.4057 can be deformed, punched and cold-worked to a certain point.
Sveising
When welding 1.4057 with a matching filler, the work piece is usually heated to a temperature
of between 100 °C and 300 °C prior to welding and is tempered as soon as possible after welding
to restore some ductility to the weld zone. For optimal properties, the entire work piece should
be re-heat treated. When the mechanical properties are not of primary concern, then Novonit®
4430 eller 4370 can be used as the filler material. When these two fillers are used, pre-heating
of the work piece is not required. Care must be taken to ensure that no nitrogen or carbon
containing gasses are used for the shielding gas since this can adversely affect the properties
of the weldment. To ensure adequate corrosion resistance of the weldment, any spatter or heat
tint must be removed.
Benefits of Using 1.4057 Rustfritt stål
- Easy to machine into complex parts
- Suitable for applications that are hygiene-critical
- Good resistance to seawater and water of varying salt concentrations
Applikasjoner
- Marine systems
- Pump & propeller shafts
- Outboard motor driveshafts
- Valve stems
- Aircraft components
- Axles
- Beslag
- Bolts & nuts