28.4.2009 Brazing

New iron-chromium based brazing filler metal for demanding stainless steel applications

4th International Brazing & Soldering Conference (IBSC), in Orlando, Florida. Author: Ulrika Persson, M Sc, Höganäs AB. Nickel based brazing filler metals are commonly used in applications with high demands. Due to fluctuating raw material costs the performance of a low cost alternative to the Nickel based alloys was investigated. This paper presents an iron-chromium based brazing filler metal appropriate for brazing stainless steel. The alloy is suitable for brazing heat exchangers and EGR coolers with tough requirements on strength and corrosion resistance. The new brazing filler metal was tested in several brazing trials. The brazed joints were investigated by metallographic examinations, joint strength and corrosion resistance. The target was to benchmark against commercial available brazing filler metals. The investigations show that the alloy has excellent wetting and brazing on 316L stainless steel. The microstructure consists of a homogenous mixed matrix. The brazed joint has high strength and good corrosion resistance. The brazing temperature for the alloy is lower than for BNi5.