DESIGN AND PROCESS DESCRIPTION OF WELDED JOINTS IN GENERAL-PURPOSE STRUCTURAL STEELS

Ensuring the durability and longevity of welded joints in metallic structures is an important problem of life support, especially in the conditions of the North. Welded joints are the crucial areas reducing resistance to brittle failure, and heat-affected zones (HAZ) are their weakest sites in terms of cold resistance. Thermokinetic diagrams and diagrams of anisothermal decay of austenite (ADA) are used for the determination of the structure composition and mechanical characteristics of the HAZ metal in the welding of many structural steels for various purposes. To choose optimum rates of cooling by preheating of products to be welded, the structure composition and mechanical characteristics of the HAZ metal, we use a carbon equivalent Ce. Besides, in terms of the effect of design and process factors on the formation of welded joints, the paper shows the necessity of controlling welding consumables when welding general-purpose steels.