A New Method of Edge Crack Suppression in the Rolling Process of Magnesium Alloy Sheet and Study on the Method of Cathodic Protection

Xintao Li,Haibin Li,Yong Niu,Chenglong Yang,Yanchun Zhu

doi:10.1155/2020/3169517

Abstract

A new method is proposed to solve edge cracking and corrosion in rolling process of the magnesium alloy plate. Usually in the process, the edge cracking is caused by the great temperature difference between the edge and the center of the alloy plate and the corrosion is by water in air. The method uses hot air wrapped around the plate to perfectly prevent edge cracking and corrosion. The method also includes cathodic protection for the magnesium alloy based on electrochemistry. The suppression of cathodic protection on the chemical activity of the magnesium alloy was studied. The experiment shows that the new method of edge heating with hot air wrapping is effective to prevent edge cracking and corrosion. Also, the cathodic protection can effectively suppress the chemical activity of the magnesium alloy and improve the surface quality in the rolling process of the magnesium plate, which provides a new concept in rolling process of the magnesium alloy.

Highlights

Magnesium alloys are new materials for the biomedical and automobile industries. e alloys have a lot of properties, such as low density, high specific strength, high specific stiffness and fatigue strength, good thermal conductivity, good damping and vibration reduction, good cutting performance, and easy recycling, that leads to numerous industrial applications [1,2,3]. e environment control of rolling equipment has a great effect on the quality in the rolling process of the magnesium alloy [4,5,6]
The flame heating method can effectively eliminate the local heating caused by the temperature difference between the center and the edge, the magnesium element in the magnesium alloy has active chemical properties, which is easy to induce the modification of the magnesium alloy and even induce the spontaneous combustion accident of the magnesium alloy
According to the basic principle of air flow, the traditional conveying roller table is shown in Figure 1(a). e rapid air flow will be formed on both sides of the magnesium alloy plate

Summary

Introduction

Magnesium alloys are new materials for the biomedical and automobile industries. e alloys have a lot of properties, such as low density, high specific strength, high specific stiffness and fatigue strength, good thermal conductivity, good damping and vibration reduction, good cutting performance, and easy recycling, that leads to numerous industrial applications [1,2,3]. e environment control of rolling equipment has a great effect on the quality in the rolling process of the magnesium alloy [4,5,6]. Combined with the study of cathodic protection, the method realizes to suppress edge crack and hydrogen corrosion [44, 45] in rolling process of the magnesium alloy plate and effectively improve the forming quality of the magnesium plate [46]. Because of the obstacle of the magnesium alloy, the hot air produced by the heat preparation box will be wrapped on both sides, forming the temperature compensation for the both edges of the magnesium alloy plate. E temperature compensation roller equipment achieves the purpose of heating at both edges of the magnesium alloy, collects harmful gases and dust, and eliminates potential hazards by the approximate steady temperature field formed by recycling hot air convection. The magnesium alloy plate is frictionally connected with the conductive layer of the conductive roller under gravity. e negative voltage of the plate realizes cathodic protection and reduces the complex

Figure 8

Design of the Experimental Equipment and Methods

Experimental Results and Analysis

Conclusion