316L不锈钢在Zn-5%Al合金液中的长期热浸镀行为研究

Study on Long-Term Hot Dipping Behavior of 316L Stainless Steel in Zn-5%Al Alloy Melt

为了明确316L不锈钢在450℃的Zn-5%Al(质量分数,下同)合金液中的长期热浸镀行为,采用扫描电镜(SEM)、能谱仪(EDS)、X射线衍射仪(XRD)、电化学剥层法等测试手段,分析了Zn-Al合金液与不锈钢基体界面处金属间化合物的形成和生长规律。结果表明:在长期热浸镀过程中,Zn-Al合金液和不锈钢基体界面处始终形成一层致密而连续的Fe_(4)Zn_(13)(FeAl_(3))金属间化合物相层。该相层随浸泡时间的延长而增厚,当316L不锈钢在Zn-Al合金液中的热浸镀时间超过240 h后该相层达到生长与溶解动态平衡。不锈钢中Cr、Ni元素对FeAl_(3)相层起到了稳定作用。连续致密且稳定的金属间化合物层是316L不锈钢在Zn-5%Al合金液中具有良好稳定性的原因。

With the aim of researching the long-term hot dipping behavior of 316L stainless steel in Zn-5%(mass fraction,the same below)Al alloy melt at 450℃,the formation and growth rules of intermetallic compounds at the interface between Zn-Al alloy melt and stainless steel substrate were analyzed by scanning electron microscope(SEM),energy dispersive spectrometer(EDS),X-ray diffractometer(XRD)and electrochemical stripping method.Results showed that during the long-term immersion process,the interface between Zn-Al alloy melt and the stainless steel substrate always maintained a dense and continuous phase layer of intermetallic compound Fe_(4)Zn_(13)(FeAl_(3)).The thickness of the layer increased with the prolongation of the immersion time,but when the hot dipping time exceeded 240 h,the growth and dissolution of the layer achieved a dynamic equilibrium.Furthermore,the Cr and Ni elements in stainless steel had a stabilizing effect on the Fe Al_(3)phase layer.A continuously dense and stable intermetallic compound layer was the essential reason for the good corrosion resistance of 316L stainless steel in Zn-5%Al alloy melt.