AISI4140 seamless tube
AISI4140 seamless tube Mechanical properties
tensile strength σ b（MPa）：≥1080（110）
yield strength σ s（MPa）：≥930（95）
elongation δ 5（%）：≥12
Area shrinkage ψ (%)：≥45
Impact energy Akv (J): ≥ 63
Impact toughness value α kv(J/cm2)：≥78(8)
Hardness: ≤ 217hb
heat treatment
Annealing annealing No. 1 760 ± 10 ℃ annealing, furnace cooling to 400 ℃ air cooling.HB220-230
Normalizing No.4 860 ± 10 ° C, normal air cooling.
Quenching + tempering No.5 840 ± 10 ℃ quenching or oil (depending on the complexity of the product), 680-700 ℃ tempering. HB
Tempering quenching + tempering No 6 840 ± 10 ℃ quenching oil, 470 ℃ tempering. HRC41-45
Quenching and tempering + quenching and tempering No.7 840 ± 10 ℃ quenching oil, 480 ℃ tempering. HRC35-45
Tempering quenching + tempering No 8 quenching at 850 ° C and then tempering at 510 ° C. HRC38-42
Quenching and tempering + tempering No 9) quenching at 850 ℃ and tempering at 500 ℃. HRC40-43
Quenching and tempering + tempering No 10 850 ℃ quenching and then 510 ℃ tempering. HRC36-42
Quenching and tempering + tempering No 11 quenching at 850 ℃ and then tempering at 560 ℃. HRC32-36
Tempering quenching + tempering No 12 860 ° C quenching followed by 390 ° C tempering. HRC48-52。