X70/316L复合轧制界面结合性能影响因素研究

Influencing factors for bonding performance of composite rolled X70/316L

采用轧制法对X70管线钢和316L不锈钢进行复合,试验结果显示增大高温阶段轧制道次压下率有助于界面的冶金结合。对复合界面进行微观观察,发现在界面处出现了Cr,Ni的富集及Fe元素的减少,原因在于基板、复板两侧存在较大的浓度梯度,导致在高温下合金元素由高浓度向低浓度扩散;界面处断续分布着Cr,Si,Fe,Ni的氧化物,是造成界面结合强度较低的主要原因。

X70 pipeline and 316L stainless steel were combined by clad rolling,experimental results show that increasing reduction rate for rolling pass at high temperature was conducive to interface metallurgical bonding. By microscopic observation for clad interface, it was found that Cr, Ni enriched in the interface, meanwhile the content of Fe decreased, which was caused by large concentration gradient between base plate and clad plate, and it led to the diffusing of alloy elements from high concentration region to low concentration region at high temperature. Discontinuous distribution of Cr, Si, Fe, Ni oxide in. the interface was the main reason for the lower interface bonding strength.