Can Stainless Steel be Welded?
Welding, the process of joining two metals together, has been around for thousands of years and dates all the way back to the Bronze Age. Of course, technology has changed in countless ways since this time but the purpose of welding remains the same. In this edition of the BS Stainless blog, we focus on the welding of stainless steel.
The short answer to the question posed in the title of this article is yes. It is, however, important to note that there are some differences as compared to welding other common metals like carbon steel or mild steel.
One of the first considerations that must be made is the fact that stainless steel is very effective at retaining heat. By its very nature, welding involves the use of extremely elevated temperatures and this means that stainless steel can sometimes warp or become otherwise distorted during the welding process. The cooling process after welding must also be carefully controlled to avoid the material warping or even cracking. In addition, welding can also leave scratches and other blemishes if not carried out by an experienced welder.
Different types of stainless steel present correspondingly-different challenges. Ferritic steel has a notably low maximum interpass temperatures so must be heated using a low heat input, otherwise its inherent strength can be negatively impacted. Martensitic stainless steel needs careful preheating if it is not to be at risk of cracking. Austenitic stainless steel is prone to cracking if the heat input is too high, especially if the weld is concave or flat.
A crucial aspect of welding stainless steel is to choose the right grade of TIG or MIG welding wire, sometimes referred to as 'filler material'. This must be of the same grade as the base material or higher. When welding grade 304 stainless steel, for example, grade 304 or grade 316 welding wire should be used.
TIG Welding
Though slower than other welding processes, TIG welding produces the most precise and aesthetically-pleasing welds. It allows welding to do be using a low current and thus a low input of heat, providing better control and reducing the potential for distortion. It is especially useful when welding thin pieces of stainless steel.
MIG Welding
Much faster than TIG welding and often fully automated, MIG welding is widely used in production facilities. While MIG welds are not as visually neat as TIG welds, they are reliably solid, especially when it comes to thicker materials. The power source is pulsed, improving quality and creating a cleaner weld. Stability is further enhanced with gas mixtures including gases such as helium and oxygen.
BS Stainless is a leading supplier of stainless steel wire, including MIG and TIG welding wire in many grades and of absolutely superlative quality; these products are made available to our customers at an extremely competitive price point. Please browse our website or get in touch with our expert technical team for further details.