基于包套压缩的高铬铸铁塑性变形行为及力学性能

Plastic deformation behavior and mechanical properties of high chromium cast iron based on canning compression

采用包套压缩工艺对本征脆性高铬铸铁进行了热压缩加工。将高铬铸铁与软韧碳钢包套组坯以后,采用热模拟试验机在温度为1150℃、应变速率为0.01 s-1和压下量分别为10%、30%、50%的条件下进行热压缩实验,研究了高铬铸铁在包套压缩工艺下的宏观热塑性变形行为、微观组织演化和力学性能。结果表明,碳钢包套施加的三轴压应力状态有助于抑制高铬铸铁热变形过程中的裂纹萌生和发展,施加碳钢包套后,高铬铸铁可以实现较大变形量的热塑性变形,并且没有出现宏观裂纹和损伤。热压缩塑性变形细化了高铬铸铁中M7C3碳化物的微观晶粒尺寸。通过测定纳米硬度证实了高铬铸铁碳化物的微区硬度随着压下量的增加得到了强化。

The canning compression process was used to perform hot compression processing of brittle high chromium cast iron(HCCI).After assembling HCCI and tough carbon steel cladding into billets,the hot compression experiments were carried out under the condition of temperature of 1150℃,strain rate of 0.01 s-1 and reduction of 10%、30%and 50%by Gleeble-3800 thermo-mechanical simulator.The macro hot plastic deformation behavior,microstructure evolution and mechanical properties of HCCI under cladding compression process were investigated.The results show that the triaxial compression stress applied by carbon steel canning is benefical to inhibit the initiation and growth of cracks of HCCI during the hot deformation.After applying carbon steel cladding,HCCI can achieve larger deform-ation amount of hot plastic deformation,and there is no macro cracks and damage.Hot compression plastic deformation refines the micro-scopic grain size of M7C3 carbides in HCCI.It is verified that the microcell hardness is improved with the increase of reduction by the nano-hardness test.