SKH53 chemical composition
Carbon C: 1.00 ~ 1.10 (promise deviation: ± 0.01)
  Si Si: 0.20 ~ 0.45 (promise deviation: ± 0.05)
  Manganese Mn: 0.15 ~ 0.40 (promise deviation: 0.04)
Sulfur S: ≤ 0.030 P P: ≤ 0.030
   Chromium Cr: 3.75 ~ 4.50 (promise deviation: ± 0.05)
Ni: to promise the residual content of ≤ 0.30
Copper Cu: agreed to the residual content of ≤ 0.25
Vanadium V: 2.25 ~ 2.75 (promise deviation: ± 0.05)
  Mo Mo: 4.75 ~ 6.50 (promise deviation: size ≤ 6, ± 0.05; size> 6, ± 0.10)
Tungsten W: 5.00 ~ 6.75 (promise bias: dimensions ≤ 10, ± 0.10; size> 10, ± 0.20)

SKH53 mechanical properties
Hardness: the hardness of delivery: (other processing methods) ≤ 269HB; (annealing) ≤ 255HB. Quenching and tempering heat treatment system and the sample hardness: ≥ 64HRC
SKH53 heat treatment process
Standard heat treatment: quenching, 730 ~ 840 ℃ preheating, 1190 ~ 1210 ℃ (salt bath) or 1200 ~ 1220 ℃ (box-type furnace) heating, oil cooling, 540 ~ 560 ℃ tempering two times, each time 2h.
SKH53 delivery status
Hot rolling, forging, annealing cold-drawn steel bar to the state of delivery, hot-rolled, forged steel bar to annealing + other processing methods (peeling, light pull, grinding or polishing, etc.) after the delivery process