Stainless steel: 4Cr13 Standard: GB / T 1220-1992 ● Features and Scope: 4Cr13 3Cr13 characteristics of high hardness after quenching than some, good corrosion resistance. Used as a high hardness and high wear resistance of heat pumps, valves, valves, bearings, medical equipment, springs and other parts. ● Chemical Composition: Carbon C: 0.36 ~ 0.45 4Cr13 stainless steel silicon Si: ≤0.60 Mn Mn: ≤0.80 sulfur S: ≤0.030 Phosphorus P: ≤0.035 Chromium Cr: 12.00 ~ 14.00 Ni: to allow contains ≤0.60 ● Mechanical Properties: Hardness : annealing, ≤201HB; quenching and tempering, ≥50HV ● heat treatment and microstructure specifications: Heat treatment specifications: 1) annealing, 800 ~ 900 ℃ slow cooling or rapid cooling to about 750 ℃; 2) quenching, 1050 ~ 1100 ℃ oil cooling ; 3) tempering, 200 ~ 300 ℃ rapid cooling. Microstructure: Organizing for the martensite type. ● Delivery status: to heat treatment delivery in general, the treatment types specified in the contract; not indicated, by not heat treatment delivery. ● annealing generally 780-800 degrees using annealing, heat 4-6 hours to ≤50 degrees / hour, cooled to 550 degrees baked cooled, isothermal annealing using 2-4 700-800 degrees insulation sales, then 670-720 degrees insulation keep 2-4 hours to ≤50 ° / hr cooling rate was cooled to 500 degrees baked cooled, annealed hardness 241-197HB