Straight welded joint crack sensitivity evaluation method and multivariant restraining plate for evaluating

Abstract

The invention discloses a straight welded joint crack sensitivity evaluation method and a multivariant restraining plate for evaluating, applied to a process of producing a large-diameter longitudinal submerged arc welded pipe by a pipeline steel plate, particularly applied to evaluating welding cold crack sensitivity of the pipe made of the pipeline steel plate under large restraint. The multivariant restraining plate comprises a lower restraining base plate (1) and an upper restraining sleeve plate (2), wherein the upper restraining sleeve plate (2) covers on the lower restraining base plate, and the upper restraining sleeve plate is used for clamping and restraining the pipeline steel plate to be evaluated between the lower restraining base plate and the upper restraining sleeve plate, and enabling the welding groove of the pipeline steel plate to be evaluated to be positioned at a welding position between the lower restraining base plate and the upper restraining sleeve plate. The method comprises the steps of: prewelding under the protection of high-speed melting polar gas, machining a double-Y-shaped groove with a thick truncated edge on the pipeline steel plate to be evaluated for welding; placing for more than 24 hours after the welding is completed, performing non-destructive testing to the welded joint by using a manual ultrasonic non-destructive testing device with an angular sensor, and evaluating. According to the straight welded joint crack sensitivity evaluation method and the multivariant restraining plate for evaluating, the actual situation when a large-diameter longitudinal submerged arc welded pipe is welded can be comprehensively reflected.

Description

technical field [0001] The invention relates to a technology for evaluating the sensitivity of welding cracks in the process of preparing straight seam submerged arc welded pipes from pipeline steel plates, especially the technology for evaluating the sensitivity of cold cracks in welding cold cracks of pipeline steel plates under relatively restrained conditions. The present invention designs multi-element restraint plates including restraint bottom plates and restraint sleeve plates, etc., and conducts welding cold crack sensitivity evaluation for relatively large-scale pipeline steel plates for pipe making, from the dimensions of welding test plates, restraint conditions, welding joint design, welding process Methods and specifications, etc., comprehensively reflect the actual situation of large-diameter longitudinal welded pipe welding. The invention can also be used to evaluate the welding crack sensitivity when different kinds of welding material combinations, welding pr...

AI Technical Summary

Problems solved by technology

So far, no technology and evaluation method have been found that can directly reflect the crack sensitivity under the welding conditions of pipeline steel plate pipes, especially the sensitivity to welding cold cracks

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