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.