1, heat-resistant steel is resistant under high temperature creep resistance to hydrogen embrittlement damage and antioxidant capacity, and corrosion-resistant steels certain media. Chemical composition and microstructure by the microstructure, can be divided into pearlite steel, martensitic steel, austenitic steel. Note alloying elements chromium, molybdenum, vanadium, niobium, titanium, tungsten, nickel, etc., to ensure the strength of steel and hot corrosion resistance. 2, and heat-resistant steel supporting Welding Electrode, mainly used for welding high temperature and pressure, hydrogen embrittlement resistance under the conditions of the pipeline, container, petroleum refining, and steel cracking unit reactor, heat exchanger, etc. To improve the weld crack resistance, the use of low hydrogen type electrode. 3, more heat-resistant steel alloy elements, welding hardened larger, should be preheated before welding and interpass temperature control, slow cooling after welding or high temperature before cooling has not been tempered. 4, dissimilar steel welding, component selection and adapt to the middle of the welding material, and poor welding material according to the appropriate choice of preheat temperature and post weld heat treatment conditions. 5, used alone or when used for welding thick-walled tube, the choice of type of heat-resistant steel, low hydrogen Aluminium Welding Electrode. 6, before welding weldments remove rust, oil, water and other magazines, especially for R517A, R717A, R727A and other electrode. 7, the electrode R307B, R407B, etc., DC reverse, when using a short arc welding operation, in order to narrow weld is appropriate. 8, with Cr content is below 5% pearlite, when more than 5% martensite. Cr-Ni austenitic steels. 9, in the thin-walled pipe welding, widely used welding backing, acid covered surface electrode process. 10, heat-resistant martensitic steel welding, crater cracking full attention to the problem, with many "point arc" method to fill the crater.
Modern architecture is basically a pressure vessel welding structure. Welding is the main pressure vessel manufacturing process means. The electrodes are the most commonly used welding material. Depending on the purpose and performance, Welding Electrodecan be divided into nine categories.
â‘ structural steel electrode (common low-alloy steel is also included in this category): this type of deposited metal electrode, at room temperature, the natural environment has a certain mechanical properties.
â‘¡ heat-resistant steel, molybdenum and chromium-molybdenum electrodes: These electrodes deposited metal, with varying degrees of heat to work.
â‘¢ stainless steel electrode: these deposited metal electrode, at room temperature, high or low temperatures with different degrees of resistance to atmospheric corrosion medium corrosion and certain mechanical properties.
â‘£ welding electrodes: These electrodes designed for welding the metal surface, the deposited metal at room temperature and high temperature has a certain degree of resistance to different types of wear or corrosion properties.
â‘¤ low-temperature electrodes: These electrodes deposited metal, in different media under the conditions of low temperature, low temperature has a certain ability to work.