Research on a Development Method for Nickel-Based Brazing Filler Metals Based on Stainless Steel Brazing Technology

The article designs the composition of nickel-based brazing filler metals for stainless steel brazing. Through vacuum brazing experiments, the tensile strength and wettability of brazed joints with different filler metal compositions are obtained. The influence of different alloy elements in the nickel-based brazing filler metals on the tensile strength and wettability of the joints is analyzed. Research results indicate that manganese and silicon in the brazing filler metal lower its melting point. Additionally, the addition of silicon enhances oxidation resistance and improves fluidity. The inclusion of molybdenum enhances the wettability of the brazing filler metal on the weldment. Combined with rare earth elements, it further improves the brazing filler metal’s ability to fill gaps, increases the toughness and strength of the brazed joint, and mitigates the high brittleness of the brazed joint caused by the presence of silicon. In addition, chromium can form an antioxidant layer, enhancing the corrosion resistance of brazed joints. Taking into account factors such as the melting temperature range of the brazing filler metal, preparation process, toughness, and spreadability, the composition range of Mn, Mo, Cr, Si, and rare earth elements in the brazing filler metal is determined as follows: Mn element mass fraction of 8 ~ 17%, Mo element mass fraction of 2 ~ 6%, Cr element mass fraction of 10 ~ 20%, Si element mass fraction of 0.5 ~ 3%, and rare earth element mass fraction of 2 ~ 10%.