Partial post-weld heat treatment method for butt joint of connecting pipe seat

A butt joint and post-heat treatment technology, which is applied in heat treatment furnaces, heat treatment equipment, heat treatment process control, etc., can solve the problems of deteriorating heat treatment temperature field, increasing joint residual stress, and joint performance damage, so as to overcome adverse effects and avoid additional The effect of stress

Inactive Publication Date: 2016-04-06
SUZHOU NUCLEAR POWER RES INST +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The excursion of the maximum temperature deteriorates the heat treatment temperature field, increases the residual stress of the joint after heat treatment, and has an adverse effect on the performance and life of the joint, especially when the maximum temperature of the excursion exceeds the phase transition point of the material, the material regenerates Crystallization will cause serious damage to the performance of the joint, and even directly lead to the scrapping of the joint

Method used

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  • Partial post-weld heat treatment method for butt joint of connecting pipe seat
  • Partial post-weld heat treatment method for butt joint of connecting pipe seat
  • Partial post-weld heat treatment method for butt joint of connecting pipe seat

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0080] The cylinder material of a header is P91 steel, the material of the connecting seat is T91, the specification of the connecting seat is OD63.5×18 (mm), the height of the connecting seat is 90mm, the material of the pipe connected to the connecting seat is T91 steel, and the specification is OD63. 5×18 (mm). The welding process requires post-weld heat treatment for the butt joint of the nozzle seat. The given process parameters for post-weld heat treatment are: constant temperature 750°C, constant temperature time 2h, time from room temperature to constant temperature 2.5h, cooling from constant temperature The cooling rate to 300°C is 300°C / h.

[0081] Using the method of the present invention to carry out post-weld heat treatment on the butt joint of the socket, the specific implementation steps are as follows:

[0082] (1) Arrangement of thermocouples: Arrange one thermocouple on the butt weld as the temperature control thermocouple of the main heating device; arrang...

Embodiment 2

[0092] A nozzle socket on a steam drum body has been repaired by welding. After the repair, post-weld heat treatment is required for the butt joint of the nozzle socket. The material of the steam drum body is SA299, the material of the connecting seat is 20MnMo, the specification of the connecting seat is OD273×28(mm), and the length of the connecting seat is 100mm; the material of the pipe is 20G, and the specification is OD273×22(mm). The given post-weld heat treatment process parameters are: constant temperature temperature 600°C, constant temperature time 1.5h, time for heating from room temperature to constant temperature is 2h, time for cooling from constant temperature to 300°C is 1.0h.

[0093] Using the method of the present invention to carry out post-weld heat treatment on the butt joint of the socket, the specific implementation steps are as follows:

[0094] (1) Arrangement of thermocouples: Arrange one thermocouple on the butt weld as the temperature control ther...

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PUM

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Abstract

The invention relates to a local post weld heat treatment method for an adapter tube seat butt joint. A main heating device and an auxiliary heating device which are independently arranged are adopted; heating elements of the main heating device are symmetrically arranged at two ends of a butt weld in equal power and equal width, and the width of the heating element arranged at each end is equal to length of an adapter tube seat; a temperature control thermocouple is arranged on the butt weld; a heat treatment curve is set according to a specified post weld heat treatment process parameter; heating elements of the auxiliary heating device are arranged on a cylinder by taking a fillet weld as the center, and a temperature control thermocouple is arranged on the fillet weld; the constant temperature is a temperature at the end of an independent heating constant temperature stage of the main heating device, namely + / -30 DEG C; and the constant temperature time, the temperature rise time and the temperature reduction speed are respectively 90-110 percent of those of the main heating device. The method is suitable for local post weld heat treatment of adapter tube seats of various specifications and materials, a phenomenon that the highest temperature point in a heating area deviates from the butt weld can be effectively avoided, and the technical requirement on the post weld heat treatment of the joint is met.

Description

technical field [0001] The invention relates to a local post-weld heat treatment method for a butt joint of a socket, which is particularly suitable for the local post-weld heat treatment of the butt joint of a socket whose height is less than or equal to 3 times the outer diameter. Background technique [0002] Post-weld heat treatment is a kind of heat treatment to eliminate the residual stress of welded joints and improve the structure and performance of welded joints. The general process is: install thermocouple → arrange heating device → set heat treatment parameters → wrap insulation cotton → perform heat treatment . [0003] The cylinders of pressure vessels, headers, etc. are generally manufactured in the factory and undergo overall heat treatment, but the butt joints connecting the pressure vessels, headers and the pipes outside the cylinder are welded on site. When heat treatment is required after welding, only partial heat treatment can be carried out. Post-weld ...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C21D9/50C21D11/00
Inventor 陈忠兵吕一仕孙志强
Owner SUZHOU NUCLEAR POWER RES INST
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