SCM440 is a commonly used steel for the production of high-strength fasteners. The product has the advantages of stable composition, low harmful elements, high purity of steel, small decarburization layer, less surface defects, etc. It is easy to carry out spheroidizing annealing, low cold heading cracking rate, stable heat treatment quality and uniform hardness, and is widely used in engine, mold and other industries.
It is a medium hardenability steel, with good strength and comprehensive mechanical properties after heat treatment, good manufacturability and high yield. The maximum operating temperature is 427℃. Can be used as turbine fastener.
Characteristics and applications
1. Good quenching, can be deep quenching, rather than the market anti-saw lock surface hardening
2. Less tendency to temper brittleness
3. High temperature processability is good, beautiful after processing
4. Good welding
5. The impact absorption performance is good, the hammer will have a sense of rebound, can not carry out violent destruction advantages:
(1). Good processability (2). Good impact absorption performance (3). Easy welding
Chemical composition
C 0.38-0.43
Si 0.15-0.35
Mn 0.60-0.85
P≤0.03
S≤0.03
Cu≤0.30
Ni≤0.25
Cr 0.90-1.20
MO 0.15-0.30
Mechanical property
Tensile strength σb (MPa) : ≥1080(110)
Yield strength σs (MPa) : ≥930(95)
Elongation δ5 (%) : ≥12
Section shrinkage ψ (%) : ≥45
impact work Akv (J) : ≥63
Impact toughness value αkv (J/cm²) : ≥78(8)
Hardness: ≤217HB
Sample size: sample billet size is 25mm
