Titanium and stainless steel can be welded, but not with welding rods.
The methods used for welding titanium and stainless steel include explosion welding, friction welding, brazing, flash butt welding, and diffusion welding.
The main difficulties in welding titanium and titanium alloys to stainless steel are:
1. The melting point difference is large, about 150°C, which will cause the loss of Fe and the burning or evaporation of alloy elements, making it difficult to weld the welded joints;
2. Iron and titanium can easily form intermetallic compounds, such as TiFe, TiFe2, Ti2Fe, etc. In addition, the alloying elements chromium and nickel in stainless steel can also form brittle intermetallic compounds with titanium. At the same time, titanium is also a strong carbide-forming element, and The carbon in the steel combines to form brittle TiC.
Multiple composite brittle intermetallic compounds may also be formed between titanium, iron, chromium, and nickel. Because the intermetallic compounds are relatively brittle, the joints will be embrittled. Under the action of welding stress, it is easy to cause cracks or even fractures in the welds, resulting in joints. The plasticity and high-temperature properties deteriorate.
3. The thermal conductivity, specific heat capacity, and linear expansion coefficient of the two are greatly different, resulting in coarse grains of the weld and large welding deformation.
