Field welding and stabilizing heat treatment method of thick-wall pipeline

A technology for stabilizing heat treatment and pipelines, applied in heat treatment furnaces, heat treatment equipment, welding media, etc., can solve the problems of no successful implementation records and ineffective solutions, and achieve the effect of low equipment requirements

Active Publication Date: 2009-10-28
CHNA ENERGY INVESTMENT CORP LTD +2
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Then, B.Messer and V.0prea etc. have also proposed the improved method of stabilizing heat treatment process (seeing Optimized Heat Treatment of 347 Type Stainless Steel Alloys for Elevated Temperature Service to Minimize Cracking.Corrosion2004, Paper No.04640: 4-12, B. Messer, V.Oprea and T.Phillips), but finally failed to effectively solve the construction problems of welding and stabilizing heat treatment of austenitic stainless steel pipes containing stabilizing elements with a wall thickness of more than 50 mm
In addition, at present, there is no record of successful implementation of pipe welding and stabilizing heat treatment for pipes with a wall thickness of 321 stainless steel containing titanium exceeding 60mm and stainless steel containing niobium having a wall thickness exceeding 50mm.

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0048] [Example 1] 54 mm thick niobium-containing austenitic stainless steel 347H

[0049] Selection of welding materials: the weight ratio of chromium and nickel is 2.1, the weight ratio of manganese and silicon is 3.79, the total weight content of sulfur and phosphorus is 0.008%, the weight ratio of niobium and carbon is 10.54, and the weight content of ferrite is 7 %.

[0050] Stabilization heat treatment: electric heating is adopted, and double-sided heating is adopted. For example, when the inner diameter of the pipe is 150 mm, the length of the heating area on one side of the outer wall along the axial direction of the pipe is 230 mm, and the length of the thermal insulation area on one side of the outer wall along the axial direction of the pipe is The length is 425mm, and the length of the inner heating zone and thermal insulation zone is half of the outer wall.

[0051] When heating, control the heating rate from 300°C, and control the heating rate at no more than 80...

Embodiment 2

[0076] [Example 2] 77mm niobium-containing austenitic stainless steel 347H

[0077] Selection of welding materials: the weight ratio of chromium and nickel is 2.1, the weight ratio of manganese and silicon is 3.79, the total weight content of sulfur and phosphorus is 0.008%, the weight ratio of niobium and carbon is 10.54, and the weight content of ferrite is 7 %.

[0078] Stabilization heat treatment: electric heating is adopted, and double-sided heating is adopted. For example, when the inner diameter of the pipe is 220 mm, the length of the heating area on one side of the outer wall along the axial direction of the pipe is 350 mm, and the length of the heat preservation area on one side of the outer wall along the axial direction of the pipe is The length is 550mm, and the length of the inner heating zone and thermal insulation zone is half of the outer wall.

[0079] When heating, control the temperature rise rate from 300°C to no more than 50°C / h. Above 300°C, the tempe...

Embodiment 3

[0104] [Example 3] 88mm niobium-containing austenitic stainless steel 347H

[0105] Selection of welding materials: the weight ratio of chromium and nickel is 2.1, the weight ratio of manganese and silicon is 3.79, the total weight content of sulfur and phosphorus is 0.008%, the weight ratio of niobium and carbon is 10.54, and the weight content of ferrite is 7 %.

[0106] Stabilization heat treatment: electric heating is adopted, and double-sided heating is adopted. For example, when the inner diameter of the pipe is 270 mm, the length of the heating area on one side of the outer wall along the axial direction of the pipe is 400 mm, and the length of the thermal insulation area on one side of the outer wall along the axial direction of the pipe is The length is 650mm, and the length of the inner heating zone and thermal insulation zone is half of the outer wall.

[0107] When heating, control the heating rate from 300°C, and control the heating rate at no more than 70°C / h. ...

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PUM

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Abstract

The invention provides a field butt welding and stabilizing heat treatment method of austenitic stainless steel thick-wall pipeline containing stabilizing elements, which comprises the steps of welding and stabilizing heat treatment. In the welding materials, the weight ratio of chromium to nickel is larger than 1.6, the weight ratio of manganese to silicon is larger than 3, the total weight content of sulfur and phosphorus is less than 0.01 percent, the weight ratio of stabilizing elements to carbon is 8-11, and the weight content of ferrite is 5 to 11 percent. The method can well realize the construction of welding and heat treatment of the austenitic stainless steel thick-wall pipeline containing stabilizing elements.

Description

technical field [0001] The invention relates to on-site welding and stabilizing heat treatment of thick-walled pipelines, in particular to a method for on-site butt welding and local stabilizing heat treatment of austenitic stainless steel thick-walled pipelines containing stabilizing elements. Background technique [0002] Austenitic stainless steel pipes containing stabilized elements such as titanium and niobium, such as 321, 347, 347H and other types of stainless steel pipes, are currently widely used in oil refining and chemical industries. However, the engineering implementation of welding and stabilization heat treatment of austenitic stainless steel thick-walled pipes containing stabilizing elements has always been a difficult problem in the world's engineering circles. [0003] Cathy Shargay, an expert from Flour Daniel, a famous American engineering company, and other researches believe that when the wall thickness of austenitic stainless steel pipes containing sta...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): B23K35/24B23K9/16B23K11/11B23K33/00C21D9/50
Inventor 孙云科万国杰谢舜敏孙华山张明周亚静张亚滨
Owner CHNA ENERGY INVESTMENT CORP LTD
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