Grade: SUS631
Material: precipitation hardened stainless steel.
Executive standard: JIS G4303-1998
Materials and characteristics.
SUS631 steel is precipitation hardened stainless steel. This kind of steel is strengthened by solution treatment and precipitation of the second phase, and the hardness is about 37 43HRC, which can meet the requirements of some plastic mold forming parts. The metallurgical quality of these steels is high, and special smelting is generally used, so the purity, mirror abrasiveness, and etching processability are good, so that the mold has good precision and accuracy retention. It has good weldability, and the hardness of the surface and core is uniform.
Hardness and application of SUS631 stainless steel.
After SUS631 steel is treated by solid solution, the austenite structure is obtained, the toughness of the steel is good, the hardness is low 229HBS, it is easy to be cut, and it is convenient for cold deformation and aging treatment after processing and forming. Through aging treatment, the austenite is converted into martensite and strengthened by Nial precipitation, and the hardness of the steel can be increased to 38 40HRC, and the aging deformation is very small (0.).01%), if through cold treatment, the austenite can continue to be converted into martensite, and the hardness can be increased to 42 48HRC. This type of steel can also be nitrided to improve wear resistance, anti-seizure and mold life. SUS631 steel is mainly used for corrosion-resistant, high-wear-resistant, high-precision plastic molds.
Chemical composition parameters of SUS631 stainless steel.
Carbon (C) content: 007%
Silicon (Si) content: 100%
Manganese (Mn) content: 100%
Phosphorus (P) content: 0035%
Sulphur(s) content: 0030%
Nickel (Ni) content: 300-5.00%
Chromium (Cr) content: 1550-17.50%
Copper (Cu) content: 300-5.00%
Niobium (NB) content: 015-0.45%
Solution treatment. SUS631 steel is a precipitation hardening stainless steel, which has an austenitic structure in the solution state, with good toughness, and is easy to be cold deformed or cold worked for. The solution temperature is 1050, water or air cooled, and the hardness is 229HBS.
Aging and cold treatment.
1) The aging temperature is 760 x90min (air cooling) + 565 x90min (air cooling), and the aging hardness is 363HBS.
2) Aging and cold treatment: 950 x10min+-73 cold treatment 8h+510 x30min, hardness 388hbs.