Should be based on parent material chemical composition, mechanical properties, combined with the pressure vessel welding performance and structural characteristics, conditions of use and welding methods considering the selection of welding materials, if necessary, be determined experimentally.Weld metal properties should be greater than or equal to the corresponding value of the base material standards or to meet minimum technical conditions prescribed pattern. Various types of steel weld metal requirements are as followsWelding material standards or product samples are listed on Cast Iron Welding Wire performance of the deposited metal (excluding base metal) performance, but performance depends on welded joints weld metal (including welding; material deposited metal and base metal) and welding process, there is no any welding material in Aluminium Welding Rods process can act on welded joints in the heat affected zone and change its properties, from selection of welding materials, it can only consider the weld metal properties needed to ensure the performance of welded joints welded process (especially post-weld heat treatment line energy) cooperation.
Low-alloy heat-resistant steel at high temperature long-term work, in order to ensure high performance of heat-resistant steel, the steel required to add more of the alloy elements (such as Cr, Mo, V, Nb, etc.). In the choice of welding materials, we must first ensure that the weld and base metal properties matching with the necessary heat resistance, thus requiring the chemical composition of the weld metal and base metal should be consistent. If the weld and base metal chemical composition that much difference, high long-term use, some elements of the joint region diffusion occurs (such as carbon diffusion near the fusion line), the joint trying to performance degradation. Heat-resistant steel electrode can be generally steels and components operating temperature to choose. Optional heat resistant steel Gas Shielded Welding Wire material on the principle that the weld metal alloy composition and performance indicators consistent with the corresponding parent material, or should meet the minimum technical conditions proposed performance indicators. To improve the ability of thermal cracking of the weld metal, the carbon content of the weld should be slightly lower than the carbon content of the base material, should generally be controlled at between 0.07% to 0.15%. Since carbon and alloying elements in steel joint action of heat-resistant Stainless Steel Welding Electrodes can easily form a hardened tissue, weldability is poor. This general preheat heat-resistant steel, tempering after welding. In recent years, thin-walled pipe welding commonly used welding backing, hand acidic surface covered arc welding process, greatly improving the quality of welding. However, the crack resistance of these electrodes is inferior to low hydrogen type electrode, when used alone or when used for welding thick-walled tube, you should choose a low hydrogen type heat-resistant steel electrode.