碳扩散对非真空热轧不锈钢复合板结合性能的影响

采用非真空热轧方法制备304不锈钢/Q235碳钢复合板材,利用OM、SEM、EDS等研究了不同压下率和轧后冷却方式下复合界面夹杂物、界面组织及力学行为的演变,并分析了C扩散对复合板界面组织形成及结合强度的影响。结果表明,随着轧制压下率的增加,界面夹杂物由块状向线型、连续点状乃至弥散点状分布变化。当压下率较低(28%)时,复合板剪切断裂位于结合界面处,随着压下率增加至47%及以上,复合板断裂位置为脱碳铁素体区。另外,热轧复合板经水冷工艺处理后,由于冷却速率较快,要抑制碳钢侧C元素的扩散,避免复合界面处脱碳区域的形成,从而提高了复合界面的结合强度。

Effect of carbon diffusion on the bonding performance of non-vacuum hot-rolled stainless steel clad plates

The non-vacuum hot rolling method was employed to prepare 304 stainless steel/Q235 carbon steel clad plates. By means of OM, SEM and EDS, etc., the evolution of inclusions, interface structure and mechanical behavior of the composite interface with different reduction ratios and post-rolling cooling approaches were studied, and the effects of C diffusion on the interfacial structure and bonding strength of the clad plates were discussed. The results show that with the increase of rolling reduction ratio, the distribution of interface inclusions changes from bulk to linear, continuous point and even dispersed point distribution. When the reduction rate is low (28%), the shear fracture position of the clad plate is located at the bonding interface. As the reduction ratio increases to 47% or more, the fracture position is located at the decarburized ferrite area. In addition, for the hot-rolled clad plate treated by water cooling process, the diffusion of C element on the carbon steel side can be suppressed due to the faster cooling rate, The formation of decarburized region near the interface can be avoided, and the bonding strength of the composite interface is further improved.