通过热膨胀相变仪得到热膨胀曲线，结合显微组织和硬度测试结果，绘制Si-Mn-Mo-Cr-V低碳贝氏体钢的静态过冷奥氏体连续冷却转变曲线；利用热模拟试验机在奥氏体区对试验钢进行不同变形量的压缩变形，随后冷却到不同温度保温150 s再空冷至室温，研究了奥氏体区压缩变形对贝氏体相变和显微组织的影响。结果表明：未经奥氏体区压缩变形、奥氏体区单道次压缩变形40%、奥氏体区两道次压缩变形58%条件下，试验钢贝氏体相变起始温度分别约为400，385，300℃；奥氏体区压缩变形后试验钢在冷却过程中的贝氏体相变延迟，相变起始温度降低，且变形量越大，贝氏体相变的起始温度越低；与未奥氏体区压缩变形试验钢相比，奥氏体区变形后试验钢在冷却过程中形成的贝氏体组织明显细化，晶粒取向增多，且硬度明显升高。

The static supercooled austenite continuous cooling transition curve of Si-Mn-Mo-Cr-V low-carbon bainitic steel was drawn by thermal expanding curve obtained with thermal expansion phase change meter combined with microstructure and hardness test results. The test steel was subjected to compression deformation in austenite zone with different deformation, and then was cooled to different temperatures for 150 s and air cooled to room temperature by thermal simulation testing machine; the effect of compression deformation in austenite zone on bainite phase transformation and microstructure were studied. The results show that the initial temperatures of bainite phase transformation of test steel without compression deformation in austenite zone, with single-pass compression deformation by 40% in austenite zone and with double-pass compression deformation by 58% in austenite zone were 400, 385, 300℃, respectively. The bainite phase transformation of test steel during cooling process was delayed after compression deformation in austenite zone; the initial phase transformation temperature decreased, and the greater the deformation in austenite zone, the lower the initial temperature of the bainite phase transformation. Compared with the test steel without compression deformation in austenite zone, the bainite of the test steel with compression deformation in austenite zone became finer, the grain orientation increased, and the hardness were obviously improved.