Basic Information
20Cr, alloy structural steel. Unified digital code: A20202
Standard GB / T 3077-1999 GB / T 17107
Chemical composition
(Wt) (%)
Carbon C: 0.18 ~ 0.24
Si Si: 0.17 ~ 0.37
Manganese Mn: 0.50 ~ 0.80
Chromium Cr: 0.70 ~ 1.00
Sulfur S: to allow the residual content of ≤ 0.035
Phosphorus P: allow the residual content ≤ 0.035
Ni: to allow the residual content of ≤ 0.030
Copper Cu: to allow the residual content ≤ 0.030
Key Features
Compared with the 15Cr steel, higher strength and hardenability, quenching in oil, the critical diameter of 4 ~ 22mm, the critical quenching diameter in water up to 11 ~ 40mm, but the toughness is poor, this was still carburizing steel a tendency to grain growth, direct quenching temperature greater impact on the toughness, so the secondary hardening after carburizing need to improve the toughness of the Ministry of parts heart, no temper brittleness; steel cold plastic strain is high, drawing in cold state ; can be cutting in high-temperature normalizing or quenching and tempering conditions are good, but after annealing poor; good weldability, weld heat treatment is generally not required, but the thickness of the parts is greater than 15mm in the warm-up before welding to be 100 to 150 ℃.
20Cr, alloy structural steel. Unified digital code: A20202
Standard GB / T 3077-1999 GB / T 17107
Chemical composition
(Wt) (%)
Carbon C: 0.18 ~ 0.24
Si Si: 0.17 ~ 0.37
Manganese Mn: 0.50 ~ 0.80
Chromium Cr: 0.70 ~ 1.00
Sulfur S: to allow the residual content of ≤ 0.035
Phosphorus P: allow the residual content ≤ 0.035
Ni: to allow the residual content of ≤ 0.030
Copper Cu: to allow the residual content ≤ 0.030
Key Features
Compared with the 15Cr steel, higher strength and hardenability, quenching in oil, the critical diameter of 4 ~ 22mm, the critical quenching diameter in water up to 11 ~ 40mm, but the toughness is poor, this was still carburizing steel a tendency to grain growth, direct quenching temperature greater impact on the toughness, so the secondary hardening after carburizing need to improve the toughness of the Ministry of parts heart, no temper brittleness; steel cold plastic strain is high, drawing in cold state ; can be cutting in high-temperature normalizing or quenching and tempering conditions are good, but after annealing poor; good weldability, weld heat treatment is generally not required, but the thickness of the parts is greater than 15mm in the warm-up before welding to be 100 to 150 ℃.
