The Effect of Mechanical Milled BNi-3 Fillers on the Vacuum Brazed Joints of 2205 Duplex Stainless Steel

• Main Authors: Jia-Shiun Jang, 張嘉訓
• Other Authors: Liu-Ho Chiu
• Format: Others
• Language: zh-TW
• Published: 2001
• Online Access: http://ndltd.ncl.edu.tw/handle/76625731776014263961

碩士 === 大同大學 === 材料工程研究所 === 89 === The purpose of this study is to make brazing filler powders with different alloying compositions, via mechanical ball milling to braze 2205 duplex stainless steel by vacuum brazing; and proceed to the corrosion test of the brazed joints, hoping to get the brazed joints that have the similar corrosion properties between matrix and fillers, and further, to improve the corrosion resistance of the 2205 duplex stainless steel brazed joints. The γ phase proportion of 2205 duplex stainless steel is more while the cooling rate is slow. The amount of sigma phase precipitated is increased as the cooling rate was lowered. The starting powder (no milling) exhibits the narrow and sharp main peaks of nickel, boride and silicon elements. After 3 hours milling, most strength peak and exist few little relative weaker peak. Have partial amorphous phase grow. BNi-3 with 3 hours-ball-milled appears blocky fragments and refined. The addition of Cr2N can make the ball-milled BNi-3 powder more uniform, but the addition of Fe cannot. For BNi-3 powder, after 3 hours ball-milled, the addition of N(1% N) can not only decrease the brazed temperature(990℃～1090℃ down to 970℃～1030℃), but also improve the corrosion resistance of 2205 duplex stainless steel joints.