Martensitic stainless steel can be divided into Cr13 type martensitic stainless steel, low carbon martensitic stainless steel and super martensitic stainless steel. Cr13 type has general corrosion resistance. It is a Cr12-based martensitic stainless steel with the addition of nickel, molybdenum, tungsten, vanadium and other alloying elements. In addition to having certain corrosion resistance, it also has high high-temperature strength and high-temperature resistance. Oxidation properties.
Welding characteristics of martensitic stainless steel: Cr13 martensitic stainless steel has a particularly large hardening tendency in the weld and heat-affected zone. Hard and brittle martensite can be obtained in the welded joint under air cooling conditions. Under welding restraint stress and diffuse hydrogen Under the influence of welding, cold cracks can easily occur. When the cooling rate is small, coarse ferrite will be formed in the near seam area and the weld metal and carbides will precipitate along the crystal, which will significantly reduce the plasticity and toughness of the joint.
After the welds and heat-affected zones of low-carbon and super-martensitic stainless steel are cooled, although they all transform into low-carbon martensite, there is no obvious hardening phenomenon and they have good welding performance.