Heat treatment of 45# seamless steel pipe

45 # seamless steel pipe heat treatment
Recommended heat treatment temperature:
normalizing 850
quenching 840
tempering 600

45 # steel is high quality carbon structural steel, not high hardness and easy machining, often used as a template, tip, guide pin, etc., but must be carried out heat treatment.
1. 45 steel, after quenching and before tempering, hardness greater than HRC55 (up to HRC62) for qualified. The actual application of the highest hardness HRC55 (high frequency quenching HRC58).
2. 45 # steel, do not use carburizing and quenching heat treatment process:
Parts after tempering treatment have good comprehensive mechanical properties, are widely used in various important structural parts, especially those who work under alternating load of connecting rod, bolts, gears and shaft, etc. But low surface hardness, wear-resisting. Available conditioning + surface quenching to improve the surface hardness of parts. Carburizing process is generally used in surface wear-resisting, core impact resistance of overloaded parts, its wear resistance is higher than tempering + surface quenching. 0.8 to 1.2% of its surface carbon content and the core is in commonly 0.1 0.25% (special circumstances by 0.35%). Get very high hardness after heat treatment, surface (HRC58-62), the core of low hardness, impact resistance. If using 45 # steel carburizing, quenching after core ministries brittle martensite, lose the advantages of carburizing process. Now USES the carburizing process of material, the carbon content is not high, to 0.30%, has high intensity of core applications. 0.35% had never seen a instance. Can use conditioning + high-frequency surface hardening process, a carburizing wear-resistance of slightly.

GB/T699-1999 standard of 45 # steel seamless steel pipe recommended system of heat treatment at 850  normalizing, 840  quenching, 600  tempering, yield strength to achieve performance for no less than 355 MPa.
According to the standard GB/T699-1999 # 45 steel tensile strength of 600 MPa, yield strength of 355 MPa, the elongation is 16%, 40% reduction of area, shock wave for 39 J.