Stabilizing heat treatment method for TP347 thick-wall pipeline

Abstract

The invention discloses a stabilizing heat treatment method for a TP347 thick-wall pipeline. The stabilizing heat treatment method comprises the following steps of determining a heat treatment process; according to the determined heat treatment process, analyzing the causes of cracking in the stabilizing heat treatment; and carrying out heat treatment construction, including treatment before heattreatment and treatment of a heat treatment implementation process. According to the stabilizing heat treatment method for the TP347 thick-wall pipeline provided by the invention, the residual stressis reduced as much as possible on the basis that the stabilizing heat treatment purpose is achieved, and the stabilizing heat treatment method has important significance in industrial production. According to the stabilizing heat treatment method for the TP347 thick-wall pipeline provided by the invention, tp347 stabilizing heat treatment can be realized, and the inner and outer walls meet the temperature requirement. According to the stabilizing heat treatment method for the TP347 thick-wall pipeline provided by the invention, the effects of reducing the stress peak value and homogenizing thestress distribution can be achieved while the requirement of stabilizing heat treatment temperature is met. The method is easy to operate and wide in applicability, and the TP347 stabilizing heat treatment process with different wall thicknesses can be achieved.

Description

technical field [0001] The invention relates to a pipeline heat treatment method. In particular, it relates to a stabilizing heat treatment method for TP347 thick-walled pipes. Background technique [0002] Because TP347 material has good high-temperature oxidation resistance, wear resistance, corrosion resistance and thermal stability, it is widely used in pipeline installations of high-pressure hydrogenation units. According to the statistical analysis of accidents in some hydrocracking units, austenitic stainless steel welds and heat-affected zones are the areas with the most serious corrosion damage, so it is necessary to stabilize the welds processed on the construction site by heat treatment. In recent years, with the enlargement of refining and chemical units, the nominal diameter and wall thickness of TP347 stainless steel pipes in high-pressure hydrogenation units have also been increasing. The problem of cracks is also becoming more and more prominent. There are...

AI Technical Summary

Problems solved by technology

[0003] Due to the traditional stabilization heat treatment process, the temperature of the pipe workpiece along the thickness direction is uneven during the heat treatment process due to the excessive thickness of the workpiece pipe wall, which will cause problems such as thermal stress, deformation, cracking, and even scrapping; in order to fully heat the inner wall and achieve stability The requirements of chemical heat treatment process often lead to excessive temperature of the outer wall, so that the outer wall of the pipeline is overheated and causes tissue damage and other problems, thereby reducing the performance and service life of the pipeline workpiece

Moreover, due to the construction conditions of the site, the thick-walled pipeline often has a large temperature difference between the inside and the outside, and the thermal stress along the thickness direction is large, and the residual stress relief effect is not good. Therefore, a new local heat treatment process is proposed to achieve the purpose of stabilizing heat treatment. The reduction of residual stress is of great significance to industrial production

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