METHOD OF DETERMINING THE LENGTH OF THE REGION WHICH DOES NOT COOL DOWN BELOW THE PREHEAT TEMPERATURE IN MULTI-PASS WELDING.

One of the main conditions of preventing cold cracking in welded joints of alloy steels in multi-pass welding is to maintain the temperature of the metal of the welded joint at a specific level. In practice, this is usually achieved by preheating the welding zone to temperature T//p and using the block welding method. The size of the block (welding section) is selected in such a manner as to insure that the welded joint does not cool down to temperature below T//p during the entire course of the process as a result of self-heating. This paper focuses on the determination of the maximum length of the block which does not cool down at any point below the specific temperature T//p.