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Super duplex stainless steel casting riser cutting and welding repair method

A duplex stainless steel, riser cutting technology, applied in welding connection methods, welding equipment, welding accessories, etc., can solve the problems of easy cracking, coarse grains, high scrap rate and other problems in castings, and achieve high yield and low cost. , the effect of improving work efficiency

Inactive Publication Date: 2018-10-02
LIAONING FU-AN HEAVY INDUSTRY CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] The content of Cr in super duplex stainless steel is as high as 26%, and contains a certain amount of N. The content of ferrite in the matrix metallographic structure is close to 50%, and the higher the content of ferrite in the steel matrix, the more brittle the steel is. Larger, poorer fluidity, coarser grains, greater tendency to cause hot cracking, the above characteristics bring many difficulties to the production of super duplex stainless steel castings, especially riser cutting and repair welding, usually in The casting is carried out under the condition of over 200°C. At this time, the casting is very prone to cracks, resulting in a high scrap rate

Method used

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  • Super duplex stainless steel casting riser cutting and welding repair method
  • Super duplex stainless steel casting riser cutting and welding repair method
  • Super duplex stainless steel casting riser cutting and welding repair method

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Embodiment 1

[0044] In this embodiment, the super duplex stainless steel high temperature and high pressure corrosion resistant pump (hereinafter referred to as the pump body 10), such as Figure 2a , Figure 2b As shown, it is a three-head screw pump body, and the specific parameters are as follows

[0045] (1) Material: super duplex stainless steel 6A

[0046] (2) The composition of the main chemical components is shown in the following table:

[0047] chemical composition

C

Si

mn

P

S

Cr

Ni

Mo

N

content(%)

≤0.03

≤1.0

≤1.5

≤0.04

≤0.02

24-26

6-8

4-5

0.1-0.3

[0048] (3) The material characteristics of the pump body 10:

[0049] The material used contains 24%-26% chromium and 0.1%-0.3% N, which is higher than the chromium and nitrogen content in ordinary duplex steel. It is a super duplex stainless steel, and the ferrite content in the matrix is ​​required to reach 50%. The above has increased the difficulty ...

Embodiment 2

[0058] In this embodiment, the super duplex stainless steel high temperature and high pressure corrosion resistant valve (hereinafter referred to as the valve body 13), such as Figure 4a , 4b As shown, the specific parameters are as follows;

[0059] (1) Material: duplex stainless steel 5A;

[0060] (2) The chemical composition is as shown in the following table:

[0061] chemical composition

C

Si

mn

P

S

Cr

Ni

Mo

N

content(%)

≤0.03

≤1.0

≤1.5

0.04

≤0.02

24-26

6-8

4-5

0.1-0.3

[0062] (3) Structural characteristics of the valve body 13:

[0063] The valve body 13 is a 1500-pound valve body with relatively thick wall thickness. Therefore, the size of the riser 11 used in the design of the casting process is relatively large, and the heat generated during the riser cutting is relatively large, which is prone to cracks;

[0064] (4) Outline dimensions of valve body castings:

[0065] The maximum ou...

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Abstract

The invention relates to a super duplex stainless steel casting riser cutting and welding repair method. In the heat preservation period after casting pouring, when the temperature of a casting is reduced to 900 to 950 DEG C, a casting and a riser are jointly immersed in water to be subject to quenching and rapid cooling treatment, the casting is cooled to the room temperature, a part prepared tobe treated is exposed of water, and riser cutting and welding repair are carried out. An underwater riser cutting and welding repair method is adopted, cracks generated during casting welding repair and riser cutting can be effectively avoided, the yield is improved, and the forceful guarantee is provided for smooth production of the super duplex stainless steel casting.

Description

technical field [0001] The invention relates to the technical field of casting post-processing, in particular to a super duplex stainless steel casting riser cutting and welding repair method. Background technique [0002] Super duplex stainless steel usually refers to ultra-high cleanliness stainless steel containing Cr 25%-27%, Ni 6.5%-7.5%, Mo 3%-4%, N≤0.3%, and contains appropriate amount of Cu, W, Si and other elements. This type of steel has better local corrosion resistance and intergranular corrosion resistance than ordinary duplex stainless steel, and its weldability is also significantly improved because of its excellent corrosion resistance to seawater, organic acids and other special media. , very suitable for the manufacture of high-pressure organic salt or seawater corrosion-resistant pumps, valves and other components. Ferrite and austenite in the matrix of super duplex stainless steel account for about 50% each, so it has the characteristics of both austenit...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): B23K9/00B23K9/013B23K9/32B23K7/00B22D31/00
CPCB22D31/00B23K7/00B23K9/0026B23K9/013B23K9/323
Inventor 吕世平石鹏宋益元张凯李璐张佳秋
Owner LIAONING FU-AN HEAVY INDUSTRY CO LTD
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