Influence of rolling reduction on corrosion behavior of WE43 alloy
(1. School of Materials Science and Engineering, University of Science and Technology of China, Shenyang 110016, China;
2. Shi-changxu Innovation Center for Advanced Materials, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China;
3. School of Materials Science and Engineering, Shandong University of Science and Technology, Qingdao 266590, China;
4. State Key Laboratory for Mechanical Behavior of Materials, Xi’an Jiaotong University, Xi’an 710049, China;
5. Shandong Key Laboratory of Advanced Aluminium Materials and Technology, Binzhou Institute of Technology, Binzhou 256606, China)
2. Shi-changxu Innovation Center for Advanced Materials, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China;
3. School of Materials Science and Engineering, Shandong University of Science and Technology, Qingdao 266590, China;
4. State Key Laboratory for Mechanical Behavior of Materials, Xi’an Jiaotong University, Xi’an 710049, China;
5. Shandong Key Laboratory of Advanced Aluminium Materials and Technology, Binzhou Institute of Technology, Binzhou 256606, China)
Abstract: The corrosion behavior of WE43 alloy with different rolling reductions (0%, 25%, 45%, and 80%) at 500°C was investigated in 3.5 wt.% NaCl solution. The microstructure evolution of the rolled WE43 alloy was characterized in detail by means of optical microscopy (OM), transmission electron microscopy (TEM) and electron back-scattered diffraction (EBSD). The results show that with increasing reductions, basal texture is gradually enhanced and grain size gradually decreases. Only the alloy with 45% reduction exhibits dispersed dynamic precipitates. Immersion and electrochemical measurements demonstrate the decreasing order of the corrosion resistance of the rolled WE43 alloy: 45% reduction > 80% reduction >？25% reduction >？0 reduction. The best corrosion resistance of the WE43 alloy with 45% reduction is mainly related to a large number of finely dispersed precipitates, which are capable of promoting the formation of a compact corrosion product layer. The increased corrosion rate of the sample with 80% reduction is induced by the re-solution of the majority of precipitates into the matrix. The grain size, basal texture and deformation twins have a limited effect on the corrosion resistance of rolled WE43 alloy compared with the precipitates.
Key words: rare earth magnesium alloy; rolling reduction; precipitate; texture; grain size; corrosion hehavor