METHOD OF WELDING PETROLEUM CHEMICAL EQUIPMENT OF 10G2FR STEEL WITH CONTROL OF THE THERMAL CYCLES.

Use of automatic welding under a layer of flux with increased linear power and electroslag welding under conditions of the control of the parameters of the thermal cycles to an optimum program makes it possible to increase the productivity of the process by two to three times in comparison with the generally used method of automatic welding with reduced linear power. The use of these production methods for welding high-strength heat-treated steels is economically more effective in comparison with normalized steels of greater (20-30%) thickness. THe consumption of weld wire, flux, and power is reduced. Results of the laboratory investigations were confirmed in the production of an oil-dust collector. The apparatus was hydrostatically tested at a pressure of 69 kg/cm**2. Its weld joints were tested by nondestructive testing methods according to All-Union State Standard 7512-55. The results of these tests showed that the quality of the weld joints satisfies the requirements of All-Union Standard 26-291-71. Comparison of the values of criteria for weld joint and the base metal shows that uniform strength of the weld joints in comparison with the base metal of heat-treated 10G2FR steel may be almost reached by controlling the thermal cycle in automatic welding under flux and in electroslag welding.