GB/T 3077 20Cr alloy steel plate has good comprehensive mechanical properties after quenching and tempering at low temperature, with good impact toughness at low temperature and no obvious tempering brittleness. During carburizing, the grain size of GB/T 3077 20Cr alloy steel plate tends to grow. Therefore, secondary quenching is required to improve the toughness of GB/T 3077 20Cr alloy steel plate. Cooling quenching is not suitable.
After normalizing, when the hardness of GB/T 3077 20Cr alloy steel plate is 170-217HB, the relative chip processability is about 65%, and the weldability is medium. It should be preheated to 100-150℃ before welding, and the plasticity is medium during cold deformation.
In order to improve the wear resistance of die cavity, carburizing treatment, quenching and low temperature tempering are required after the mold is formed, so as to ensure that the die surface of GB/T 3077 20Cr alloy steel plate has high hardness, high wear resistance and good toughness. For the mold with low requirement of service life, it can also be directly quenched and tempered. There are also many examples of cold working dies made by using low carbon martensite.
GB/T 3077 20Cr alloy steel plate process route: blanking forging die blank annealing mechanical rough machining cold extrusion forming recrystallization annealing mechanical finishing carburizing quenching tempering tempering grinding polishing assembly.
