Carbide in the airport chair welding of stainless steel for corrosion resistance
In the manufacturing process of the airport chair, may the carbide welding has a certain effect on corrosion resistance: intergranular chromium carbide precipitation with the increasing of temperature sensitive area, the increase of temperature time faster.
When weld intergranular chromium carbide precipitation, corrosion resistance and resistance to stress corrosion resistance decreased obviously.
Reduced corrosion resistance, is due to appear rich chromium carbide in grain boundary, and the nearby parent metal chromium content decreased, while the intergranular carbide precipitation generally occurred in 427 -
871 degrees temperature range, but usually occurs in welding heating and cooling rapidly, so the limit sensitization effect to the narrow range, the narrower scope with the chemical composition and heat preservation time, and steel, general is about 649 -
Direct parent metal near the weld, due to welding heat annealing or solid solution treatment, at the same time because usually taken by the cooling speed quickly enough to keep the solid carbide of vast solution, because the general corrosion resistance, with normal place not far away from the weld may be depends on the thermal cycle, there is a low rate of heating and cooling of narrow area.
In the heat affected zone, intergranular chromium carbide precipitation is likely.