热轧304L/Q235B不锈钢复合板界面特征及性能分析

Characteristics of bonding interface and analysis of properties of hot-rolled 304L/Q235B stainless steel clad plate

研究了不同压下率热轧304L/Q235B复合板的复合界面的显微组织以及成分分布、剪切强度、显微硬度变化。结果表明,热轧不锈钢复合板复合界面由于C、Cr元素扩散,复合界面附近形成一定厚度的扩散层,且由于有碳化物的形成,扩散层的硬度增加,黑色带状区域为扩散层的一部分,在该区域边界,硬度达到峰值。复合界面处有黑色夹杂物形成,成分为Mn的硫化物和氧化物。碳钢侧组织为铁素体和珠光体,且随压下率增加,珠光体体积分数增加。在碳钢侧有脱碳层形成,随压下率增加,脱碳层厚度减小。复合板剪切强度随道次压下率的增加有所增加,并且剪切断口同时存在韧性断裂区域和脆性断裂区域,断裂发生在复合界面处。

Microstructure,composition,shear strength,micro-hardness of the bonding interface of 304 L/Q235 B clad plates by different reduction rates were studied. The results show that the diffusion layer exists at the interface due to the diffusion of carbon and chromium.Due to the formation of carbides,the hardness of the diffusion layer increases. The hardness reaches up to the peak value at the boundary of black area which is a part of diffusion layer. The existed black inclusions at the bonding interface consist of the eutectic of Mn S and Mn and the oxide of Si-Mn. The volume fraction of the pearlite in the steel increases with the increasing reduction rate. The width of decarburized layer decreases with the increasing reduction rate. The shear strength increases with the increasing pass reduction rate.Ductile fracture area and brittle fracture area coexists at the shear fracture.