ZG40CrNi2Mo大齿圈热加工工艺研制

Development of Heat Treatment Process for ZG40CrNi2Mo Big Gear Ring

通过热处理工艺试验,确定ZG40CrNi2Mo钢热处理参数与力学性能的关系。试验结果表明:试样正火(880℃)+回火(580℃)时,抗拉强度达到1064 MPa,屈服强度达到899MPa,延伸率达到16.8%,断面收缩率达到36%,常温冲击功KV2达到24 J,硬度达到295HB,金相组织为回火索氏体+铁素体。试样淬火(860℃)+回火(600℃)时,抗拉强度达到1034 MPa,屈服强度达到905 MPa,延伸率达到16.8%,断面收缩率达到34.3%,常温冲击功KV2达到33 J,硬度达到333 HB,金相组织为回火索氏体。根据试验结果,制定大齿圈热处理工艺方案,大齿圈经正火+回火(880℃/5h空冷+580℃/10h空冷)后,力学性能和硬度均达到图纸技术要求。

The relationship between heat treatment parameters and mechanical properties of ZG40CrNi2Mo steel was determined by heat treatment process tests.The test results showed that when the test piece was subjected to normalizing(880℃)+tempering(580℃),the tensile strength reached to 1064 MPa,the yield strength reached to 899 MPa,the percentage elongation reached to 16.8%,the percentage reduction of area reached to 36%,the impact energy at room temperature reached to 24 J,and the hardness reached to 295 HB.The metallographic structure consists of tempered sorbite and ferrite.When the test piece was quenching(860℃)+tempering(600℃),the tensile strength reached to 1034 MPa,the yield strength reached to 905 MPa,the percentage elon-gation reached to 16.8%,the percentage reduction of area reached to 34.3%,the impact energy at room temperature reached to 33 J,and the hardness reached to 333 HB.The metallographic structure consists of tempered sorbite.According to the test results,the heat treatment process of the big gear ring was developed.After normalizing+tempering(880℃/5 h air cooling+580℃/10 h air cooling),the mechanical properties and hardness of the big gear ring met the technical requirements of the drawings.