铸钢件准固态区域应力、应变数值模拟及热裂机制

NUMERICAL SIMULATION OF STRESS-STRAIN IN CASTING STEEL DURING SOLIDIFICATION AND FORMATION MECHANISM OF HOT-TEARING

对ZG45实际热裂试棒的数种工况进行了应力-应变的数值模拟，对热裂形成机制进行了讨论.研究认为：热裂起源于Bingham体，是塑性变形超过Bingham体塑性储备值所致.模拟结果表明：相对热节使Bingham体应变集中，合适的冷铁可有效地降低Bingham体应变集中，减少热裂发生的可能性.

As regard to several cases of real hot tearing ZG45 bars (C 0.42%-0.52%,Mn 0.5%- 0.8%, Si 0.2%- 0.45%), numerical simulation of stress-strain during solidification was conducted. The formation mechanism of hot tearing was discussed, and the conclusion is drawn that hot tearing originates from Bingham body and is caused when strain of Bingham body being over preserved plastic strain. The simulated results show that relative hot spot gives rise to increase in concentration strain of Bingham body, and that case of proper chilI could effectively decrease concentration strain of Bingham body, uponthere to reduce possibility of hot tearing.