1. Executive standard: ASTM A29/A29M-04
2. Features:
1) Good processability, small processing deformation.
2) The fatigue resistance is quite good, it is medium hardenable steel, 4140 has good strength and good comprehensive mechanical properties after heat treatment, good manufacturability, and high yield. The maximum operating temperature is 427 degrees Celsius.
3) 4140 seamless steel pipe has high strength, hardenability, good toughness, small deformation during quenching, high creep strength, and enduring strength at high temperature. It is used to manufacture forgings that require higher strength and larger quenched and tempered section than 35CrMo steel, such as large gears for locomotive traction, supercharger transmission gears, rear axles, connecting rods, and spring clips that are heavily loaded, and can also be used drill pipe joints and fishing tools for oil deep wells below 2000m, and can be used for molds of bending machines.
3. Chemical composition
Region: China
Standard: GB/T 3077-1999
Carbon (C) 0.38~0.45.
Silicon (Si) 0.17~0.37
Manganese (Mn) 0.50~ 0.80
Phosphorus (P) ≤0.035
Sulfur (S)≤0.035
Chromium (Cr) 0.9~ 1.20
Nickel (Ni) 0.030
Molybdenum (Mo) 0.15~0.25
Copper (Cu) 0.30
4. Mechanical properties
Tensile strength (MPa) ≥1080 (110)
Yield strength (MPa)≥930(95)
Elongation ≥12
Reduction of area ≥45
Impact energy Akv(J) ≥63
Impact toughness value (J/cm2) ≥78(8)
Hardness≤217HB
5. Heat treatment specifications and metallographic structure
Heat treatment specification: quenching 850C, oil cooling; tempering 560C water cooling, oil cooling.
Metallographic structure: tempered sorbite
6. Delivery status
Delivery in heat treatment (normalizing, annealing, or high-temperature tempering) or without heat treatment.
