Cold welded steel pipe cracks
Date:2018-01-18 View:430 Tag:Cold welded steel pipe cracks
The reason of the cold crack is the process of the hardenability of the welding material which is easy to be cooled by the people when being welded. The cooling speed of the welding is too late for the residual hydrogen in the weld to escape. The molecular hydrogen of a hydrogen atom Of the metal pores cause a lot of pressure, so that the pressure of local metal cold bending cracks; focus on hydrogen embrittlement and hardening of the welding stress and tensile stress analysis at the same time prone to the formation of cold cracks.
Preventive measures: pre-welding and slow cooling after welding, heat-affected zone decomposition of austenite can be sufficient temperature range, to avoid hardening of the organization, while reducing the role of welding stress; timely after low temperature annealing, dehydroepiandrosterone Treatment, elimination of stress generated during welding, and timely diffusion of hydrogen to the outside; choice of low-hydrogen type and alkaline flux or austenitic stainless steel wire, and other consumables dry and strict purification tank; protection and strengthening of welding Clean the surface to avoid invasion of hydrogen; choose a reasonable welding specification, using a reasonable assembly of three-dimensional welding sequence.