20CrMo directory 


 Grade: 20CrMo Standard: GB / T 3077-1988 corresponding to the standard: JIS G4053: 2003 ASTM A29M: 2005 ISO 683-18:1996 uniform digital code: A30202 
 Natural science 
 ● Features and Scope: the higher hardenability, non-temper brittleness, very good weldability, cold cracking tendency to form small, cutting and cold can be a good strain plasticity. General conditioning or carburizing conditions used for the manufacture of non-corrosive medium and temperature lower than 250 ℃, the medium containing a mixture of nitrogen and hydrogen in high pressure pipe work and a variety of fasteners, higher carburizing parts such as gears and shafts. ● Chemical Composition: C: 0.17 ~ 0.24 Si Si: 0.17 ~ 0.37 Manganese Mn: 0.40 ~ 0.70 S S: agreed residual phosphorus content ≤ 0.035 P: ≤ 0.035 promise residual content of chromium Cr: 0.80 ~ 1.10 Ni: to agree the residual content of ≤ 0.030 Copper Cu: Mo promised residual content ≤ 0.030 Mo: 0.15 ~ 0.25 ● Mechanical Properties: Tensile σb (MPa): ≥ 885 (90) yield strength σs (MPa): ≥ 685 (70) Elongation δ5 ( %): ≥ 12 Reduction of area ψ (%): ≥ 50 Impact energy Akv (J): ≥ 78 impact toughness αkv (J/cm2): ≥ 98 (10) Hardness: ≤ 197HB sample size: the sample blank standard size 15mm ● Heat treatment and microstructure: heat treatment specifications: quenching 880 ℃, water, oil cooling; tempering 500 ℃, water-cooled, oil-cooling. ● Delivery status: to heat treatment (normalizing, annealing, or tempering) or heat treatment delivery, delivery status should be indicated in the contract. ● 20CrMo heat treatment: 20CrMo material is low carbon alloy steel for carburizing; heat treatment specifications: quenching 880 ℃, water, oil cooling; tempering 500 ℃, water-cooled, oil-cooling. ● 20CrMo hardness 20CrMo quenching (860-880 ℃ cold water or oil), plus low-temperature (150 - 200 ℃) annealing, 20CrMo hardness HRC32-33 ● Heat treatment and mechanical properties: steel: 20CrMo blank sample size / mm: 15 Heat Treatment | Hardening | Heat temperature / ℃ | first quenching: 880 Heat Treatment | Hardening | Heat temperature / ℃ | second quenching: - Heat treatment | hardening | Coolant: water, oil, heat treatment | Tempering | heating temperature / ℃: 500 Heat treatment | Temper | coolants : water, oil, mechanical properties | tensile strength σb / MPa | ≥: 885 mechanical properties | yield point σs / MPa | ≥: 685 mechanical properties | Elongation δ5 (%) | ≥: 12 mechanical properties of | ψ surface shrinkage (%) | ≥: 50 Mechanical Properties | Impact absorbed energy AKV / J | ≥: 78 
 Delivery status hardness HBS | ≥: 197