Stainless steel are magnetic like carbon steel. They are problematic to weld due to grain growth in the heat affected zone which reduces ductility and may result in cracks. Increasing chromium and molybdenum contents increase corrosion resistance as it does for austenitic stainless steels, however, this high alloying results in the precipitation of embrittling intermetallic phase upon welding. These microstructural problems due to welding restrict the use of ferritic stainless steels to very thin thicknesses and thus are not used in the construction of large heavy walled vessels and tanks, and structures like austenitic stainless steels. Common ferritic grades are: Type AISI
Duplex stainless steel are higher. This can be a great advantage when strength is important. This is the case in bridges, pressure vessels or tie bars. Chemicals composition of grades from EN 10088-1 (2014) Standard are given in the table below: Mechanical properties from European Standard EN 10088-3 (2014) (for product thickness below 160mm): <nowiki>*</nowiki>for thickess ≤ 5 mm The minimum yield stress values are about twice as high as those of austenitic stainless steels. Duplex grades are therefore attractive when mechanical properties at room tempearature are important because they allow thinner sections. Duplex stainless steel Duplex stainless steels is the most recent