Ce合金化及喷丸对Q235钢组织和力学性能的影响

Effect of Ce Alloying and Shot Peening on Microstructure and Mechanical Properties of Q235 Steel

以Q235钢为原料,添加稀土Ce重熔轧制后得到改性钢。采用高能喷丸技术对型钢进行表面强化处理。考察了不同喷丸参数对钢微观组织和力学性能的影响。结果表明:经喷丸处理后,Q235钢表面产生了明显的塑性变形,晶粒明显细化,显微硬度升高,从试样表面到心部具有明显的显微组织梯度和硬度梯度,并形成深约140μm的残余压应力层。以0.66 MPa压力喷丸后,Ce的质量分数为0.024%的钢的最大抗弯强度和抗拉强度可达713.2和366.3 MPa,比未加稀土但经过喷丸处理的钢的最大值分别提高了14.4%和13.54%,比未加稀土且未喷丸的钢的最大值分别提高了45.7%和20.02%。

Using Q235 steel as raw material,a modified steel was obtained by adding rare earth Ce and then remelting and rolling,and surface of the steel was strengthened by high-energy shot peening technology.The effect of different shot peening parameters on microstructure and mechanical properties of the steel was investigated.The results showed that after shot peening,the surface of the Q235 steel had been obviously plastic deformed,the grain was obviously refined,and the microhardness increased significantly.There were obvious microstructure gradient and hardness gradient from the sample surface to the core,and a residual compressive stress layer of about 140μm in depth was formed.After shot peening at pressure of 0.66 MPa,the maximum bending strength and tensile strength of the steels with 0.024%Ce by mass could reached 713.2 MPa and 363.5 MPa,which were 14.4%and 13.54%higher than those of the steels having no Ce but undergoing shot peening,respectively,and 45.7%and 20.02%higher than those of the steels without both Ce and shot peening,respectively.