0.12 - 0.2 %
15 - 17 %
1.25 - 2.5 %
Automotive industry, Chemical industry, Aerospace industry, Petrochemical industry, Mechanical engineering
Good - The formation of chromium carbides and the associated chromium depleted regions that form around these precipitates make this grade of steel susceptible to intergranular corrosion. Surface condition plays an important role in the corrosion resistance of this steel with polished surfaces exhibiting far superior corrosion resistance compared with rougher surfaces on the same material. PRE = 17.5 – 21.26
Poor - The machinability of this grade of stainless steel is directly related to its hardness. 1.4057 machines similar to carbon steels of the same hardness. Although it must be realised that the machining parameters will vary depending on the structure/hardness of the stee
1.4057 can be hardened by holding at a temperature between 950 °C – 1060 °C followed by cooling in air or oil. The tempering temperature is dependent on the desired strength. Since this grade of steel is susceptible to 475 °C embrittlement, care must be taken to limit exposure to the temperature range 420 °C to 520 °C, both during fabrication and service. QT900 (tempered between 600 °C and 650 °C).
It is formable at 800-1100°C
Quenched and tempered QT 900
Good - 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 or 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.