How does stainless steel’s resistance to intergranular corrosion benefit welded joints?

Stainless steel is widely valued for its exceptional resistance to intergranular corrosion, a property that significantly enhances the performance and longevity of welded joints. Intergranular corrosion occurs when grain boundaries in a metal become susceptible to chemical attack, often due to carbide precipitation during welding. Stainless steel's high chromium content forms a passive oxide layer that protects these boundaries, preventing corrosive agents from penetrating.

In welded joints, this resistance is critical because welding can create localized heat-affected zones (HAZs) where corrosion risks are higher. By minimizing intergranular corrosion, stainless steel ensures stronger, more reliable welds with reduced cracking and failure risks. This makes it ideal for industries like chemical processing, marine engineering, and construction, where durability and corrosion resistance are paramount.

Additionally, advanced stainless steel grades (e.g., 316L or 304L) with low carbon content further resist sensitization, a common cause of intergranular corrosion. Proper welding techniques, such as using low heat input and post-weld treatments, can further optimize corrosion resistance. Ultimately, stainless steel's inherent properties make it a top choice for welded structures exposed to harsh environments.