An overall heating and local cooling heat treatment process for welding seams of tube groups

Abstract

The invention discloses a whole heating and local heat dissipation type pipe group weld joint treatment process. A pipe group adopting the whole heating and local heat dissipation type pipe group weldjoint treatment process comprises a first pipeline, a second pipeline, first heat preservation cotton and second heat preservation cotton, wherein the first heat preservation cotton is applied abovea low-hardness area of a weld joint formed by welding the first pipeline and the second pipeline and is provided with a hole area, and the second heat preservation cotton is applied above the hoe area. The pipe group is characterized by also comprising a first temperature control thermocouple, a second temperature control thermocouple and a heater, wherein the first temperature control thermocouple, the second temperature control thermocouple and the heater are connected to the weld joint. The heating treatment process comprises the following steps of heating, heat dissipation and hardness detection. By adopting the method, safe operation of pipelines and pipe fittings of power plants can be ensured.

Description

technical field [0001] The invention relates to the field of welding, in particular to an overall heating and local heat dissipation type pipe group welding seam heat treatment process. Background technique [0002] In the overhaul construction of pipelines and pipe fittings in power plants, there are many cases where some pipes or pipe fittings are replaced. When the welding is resumed, there will be welding between the new pipes and the original pipes or original pipe fittings. Especially for P91 and P92 large-diameter, thick-walled high-temperature and high-pressure pipes or fittings, the welding and heat treatment processes are complicated and difficult. The existing post-weld heat treatment scheme is mainly: according to the pipe diameter specification, a plurality of thermocouples are arranged in the weld seam, and the temperature is controlled in different regions. The heaters in each zone heat up at the same heating rate at the same time, the constant temperature ti...

AI Technical Summary

Problems solved by technology

[0005] Chinese invention CN201711214445.X discloses a local heat treatment process for the girth weld of the tube plate assembly and the lower head assembly, which adopts a local heat dissipation method to achieve an overall heat dissipation effect, thereby trying to solve the hardness that is prone to occur during the heat dissipation process after welding Out of control problem, but it is mainly used in the local heat treatment of the steam generator tube sheet assembly and the lower head assembly girth weld. and cannot be used in the field to which the present invention belongs

[0006] To sum up, in the prior art, there is still no effective solution to the problem of heat dissipation during welding of power plant pipelines during maintenance

Images