Cold-drawn seamless pipe is a standard steel type in GB in my country. 40Cr steel is one of the most widely used steels in the machining industry. After heat treatment, it has excellent comprehensive physical properties, excellent ultra-low temperature fracture toughness and low gap sensitivity. 40cr seamless steel pipe has excellent cutting performance, it can be hardened to Ф28～60mm when water quenched, and can be hardened to Ф15～40mm when oil quenched. In addition to heat treatment, this type of steel is also suitable for cyanidation and induction hardening. The workability is good. When the strength is 174-229HB, the relative drilling process performance is 60%. This steel is suitable for making small and medium injection molds.
40cr seamless steel pipe composition
C:0.37~0.44 Si:0.17~0.37 Mn:0.50~0.80 Cr:0.80~1.10 Ni:≤0.30 P:≤0.035 S:≤0.035 Cu:≤0.30
Mo:≤0.10
Physical properties
Specimen blank specification (mm): 25
Tempering treatment:
The first heat treatment heating temperature (℃): 850; coolant: oil
The second heat treatment heating temperature (℃):-
Quenching heating temperature (℃): 520; Compressive strength (σb/MPa): ≥810 (when the specific strength is 25HRC) Yield limit (σs/MPa): ≥785 Breaking elongation (δ5/%): ≥9 Section Shrinkage rate (ψ/%): ≥45 Impact digestion and absorption work (Aku2/J): ≥47
Brinell hardness (100/3000HBW) (quenching or high temperature quenching): ≤207
