The Study of Corrosion Resistance and Microstructure of Bi-steels after Welding with 309 Wires

• Main Authors: Chen Bo-Chang, 陳柏彰
• Other Authors: Dr.-Ing. Dong-Yih Lin
• Format: Others
• Language: zh-TW
• Published: 2006
• Online Access: http://ndltd.ncl.edu.tw/handle/58510568380500540903

碩士 === 義守大學 === 材料科學與工程學系碩士班 === 94 === The purpose of this study is to discuss the effect of silicon content on the corrosion resistance and microstructure of bi-steels after welding with 309 wires. The experiments in this research showed that δ-ferrite increases with the increasing of silicon content in welding wires because silicon is an element acts as austenite phase stabilizer in stainless steels. The chromium content of δ-ferrite at the center of fusion zone is higher than that at the fusion line. The corrosion test showed that the materials in HAZ are corroded more serious than that in the matrix. The effect of silicon contents on corrosion resistance can be divided in two parts: the resistance against intergranular corrosion decreases with the increase of silicon content; the resistance against uniform corrosion increases with the increase of silicon content. Silicon is the major affecting element on the corrosion resistance at fusion zone. As mechanical properties were hardness of tested materials performed. The hardness of fusion zone with 0.65wt% silicon contented wires showed the highest value. The increase of silicon content in welding wires induces to the increasing of hardness of steels.