Bolt test determination method for conditioning reheat cracking sensitive temperature of high-strength steel

Abstract

The invention relates to a bolt test determination method for conditioning reheat cracking sensitive temperature of high-strength steel for a pressure container. The method comprises the following steps: firstly, cutting part of a steel plate to be tested to prepare a plurality of bolt samples and soleplates; then welding the bolt samples and the soleplates to acquire a plurality of groups of combined pieces, then mounting the welded combined pieces onto a high-temperature creep testing machine, carrying out loading test on the combined pieces under different test temperatures, and recording breakdown time, namely the time from when the combined pieces reach a preset load to when the combined pieces break down under the test temperatures, and acquiring the test temperature corresponding to the shortest breakdown time as the reheat cracking sensitive temperature of the steel plate after a lot of breakdown time is acquired. The method disclosed by the invention not only has the advantage that a Y-groove cracking test method can be compared to an actual structure, but also can acquire a relatively accurate test result; meanwhile, the method is small in measurement workload and high in measurement efficiency and is a simple and easy reheat cracking sensitive temperature determination method.

Description

technical field [0001] The invention relates to a reheat crack sensitive temperature detection method of a quenched and tempered high-strength steel plate for a pressure vessel, which is used for measuring the reheat crack sensitive temperature of the steel and provides a basis for formulating a post-weld heat treatment process for a quenched and tempered high-strength steel pressure vessel. Background technique [0002] After the pressure vessel is welded, there will inevitably be a large welding residual stress. The welding residual stress of the pressure vessel made of quenched and tempered high-strength steel is even greater. If it is allowed to exist, it will bring hidden dangers to the safe operation of the pressure vessel. For this reason, the general pressure vessel must be subjected to post-weld heat treatment after welding to eliminate welding residual stress. As the strength of quenched and tempered steel is getting higher and higher, the problem of reheat cracks ...

AI Technical Summary

Problems solved by technology

The traditional methods for measuring the sensitive temperature of reheating cracks mainly include the following: one is to use a small iron research sample to conduct tests at different heat treatment temperatures to detect the sensitive temperature of reheating cracks of the steel plate, but the accuracy of this method is very low. low, the data obtained are often too large in error, and have little guiding significance for the actual post-weld heat treatment process; another method is to use welding thermal simulation technology to simulate the microstructure of the HAZ, and then conduct high-temperature mechanical performance tests under heat treatment conditions. In order to obtain the reheating crack sensitive temperature, the test conditions of this method are far from the actual engineering application, and the accuracy of the data obtained is often poor. In addition, this test also requires expensive thermal simulation testing machine

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