Product brief introduction
20Cr Compared with 15cr steel has higher strength and hardenability, in oil critical hardening 4 ~ 22 mm in diameter and critical quenching in water through 11 ~ 40 mm in diameter, but toughness is poorer, this steel carburizing still has a tendency to grain growth, temperature and direct quenching effect on impact toughness is bigger, so need 2 times after carburizing quenching in order to improve the toughness of parts for the core, no temper brittleness.
Cold high strain and plastic steel, can be in the condition of cold wire drawing;
Cutting resistance in high temperature normalizing or quenched and tempered condition is good, but after annealing is poorer;
20 cr is pearlite, better weldability, generally do not need to heat treatment after welding, but the thickness is greater than 15 mm preheating before welding the parts to 100 ~ 150 ℃, also don't undertake tempering heat treatment after welding.
S ： ≤0.035
P ： ≤0.035
Most of the steel used in the manufacture of the demand is higher, intensity of heart surface wear, under section under 30 mm or small carburized parts of complex shape and load (oil quenching), such as: transmission gear, gear shaft, CAM, worm, piston pin, claw clutch, etc.;
For the heat treatment deformation and high abrasion resistance parts, should be high frequency surface quenching after carburizing, such as modulus is less than 3 of the gear, shaft, spline shaft, etc.
This steel can be used in the quenched and tempered state and used in the manufacture of large and medium under impact load in her work parts, this kind of steel also can be used as a low carbon martensite steel quenching, further increasing steel yield strength and tensile strength increased (about 1.5 ~ 1.7 times).