大锻件内部裂隙型缺陷焊合规律

Study on the bonding condition of inner crack defects in heavy forgings

利用Gleeble-3500热模拟实验机,对30Cr2Ni4MoV低压转子钢内部裂隙型缺陷进行高温塑性变形焊合实验,并对焊缝处的金相组织进行观察。研究结果表明,温度、时间和变形量对裂隙焊合都有影响,温度是影响裂隙焊合的主导因素,当温度、保温时间和变形量三者满足一定的组合时,裂隙型缺陷可以通过扩散和再结晶等机制实现焊合。实验中在焊合区域出现了较明显的焊合线,有的晶粒贯穿焊合线生长,达到了较好的焊合效果。采用温度1000℃和10.7%的相对变形量、保温时间60s的工艺条件,达到的裂隙焊合效果令人满意。

The tests for bonding of inner crack defects in 30Cr2 Ni4 MoV steel under hot deformation were conducted on Gleeble-3500 simulator, and the bonding condition as well as the microstructure in bonding area were studied. The results show that temperature, holding time and deformation are the three main factors that affect the bonding quality of inner crack defects. Temperature is the leading factor and the inner crack defects can he well bonded under certain combination of temperature, time and deformation through diffusion and recrystallization. A bonding line appears in the bonding area, and some grains grow across the bonding line. The test condition with a reduction of 10. 7% and kept for 60s under 1000℃ yields a satisfactory bonding quality.