奥氏体不锈钢热轧边裂实验研究

奥氏体不锈钢Cr15Mn9Cu2NiN在热轧过程中容易产生边裂.在热模拟试验机上开发出热轧实验装置,进行热轧实验,分析该不锈钢边部裂纹产生的原因.结果表明,压下量达到一定程度时,在所有变形温度下,试样边部均会产生裂纹,裂纹均沿奥氏体晶界扩展.在1000～1150℃变形时裂纹倾向较大,分析认为这与奥氏体不锈钢在此温度区间内的延性下降有关.在该温度区间内,轧后试样的微观组织具有晶粒租大和晶粒内部变形亚结构与孪晶共同存在的特征,而在1200℃变形时,晶粒尺寸较小,晶粒内部的变形亚结构和孪晶全部消失.

Experimental Study on Edge-cracking in Austenitic Stainless Steel CrlSMn9Cu2NiN during Hot Rolling

Austenitic stainless steel Crl5Mn9Cu2NiN is prone to suffer from edge cracking during hot rolling. Hot rolling test is conducted on an experimental hot rolling device, which is designed cooperate with thermal simulator. Formation mechanism of edge cracks is researched through this test. The results show that, when press quantity reaches to a certain amount, samples will crack on edge at all test temperatures. All the edge cracks propagate along austenitic grain boundaries. In the range of 1000-1150℃ deformation, cracking tend ency of samples are severe, which is related to the reduction of ductility in austenitic stainless steel. The char- acteristic of microstructures in hot rolled specimens is deformation substructures and twins boundaries in coarse grains in this temperature range. But at 1200℃ deformation, the grain size of specimens is smaller, and all substructures and twins boundaries disappear in the grains.