my country's GB standard steel number is 40Cr, German DIN standard material number 1.17035/1.7045, German DIN standard steel number 41Cr4/42Gr4, British EN standard steel number 18, British BS standard steel number 41Cr4, French AFNOR standard steel number 42C4, French NF Standard steel number 38Cr4/41Cr4, Italian UNI standard steel number 41Cr4, Belgian NBN standard steel number 42Cr4, Swedish SS standard steel number 2245, American AISI/SAE/ASTM standard steel number 5140, Japanese JIS standard steel number SCr440(H)/SCr440 , International Organization for Standardization ISO standard steel number 41Cr4.
[Critical point temperature]
(Approximate value) Acm=780℃
[Normalizing Specifications]
Temperature 850~870℃, hardness 179~229HBS.
[Specifications for Softening Treatment of Cold Pressed Blanks]
The temperature is 740~760℃, the holding time is 4~6h, and then the temperature is cooled to ≤600℃ at a cooling rate of 5~10℃/h, and then the product is air-cooled.
The hardness before treatment is ≤217HBS, and the hardness after softening is ≤163HBS.
[Specifications for Pig Iron Chip Protection Swing Tempering]
(670±10)℃×2h, with the furnace heating up, (710±10)℃×2h, with the furnace cooling, (670±10)℃×2h, with the furnace heating, (710±10)℃×2h, and then with the furnace Cool down the furnace to (670±10)℃×2h, then raise the temperature to (710±10)℃×2h, then cool down the furnace for a total of 3 cycles, then cool down to 550℃ and air-cool out of the furnace. The hardness after treatment is 153HBS.
[Specifications for quenching and tempering treatment]
Quenching temperature is 850℃ ±10℃, oil cooling; tempering temperature is 520℃±10℃, water, oil and air cooling.
