Welding method for high-nitrogen steel

A welding method and high-nitrogen steel technology, applied in welding equipment, welding/welding/cutting items, non-electric welding equipment, etc., can solve problems such as large linear expansion coefficient, reduced joint performance, and low thermal conductivity of austenitic stainless steel , to achieve high performance strength, no loss of nitrogen element, good forming effect

Active Publication Date: 2016-02-24
NANJING UNIV OF SCI & TECH +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0006] (1) The loss of nitrogen in the weld area, that is, the formation of nitrogen pores and the escape of nitrogen, reduces the solid solution nitrogen content in the weld, resulting in a decline in joint performance;
[0007] (2) The precipitation of nitrides, carbides and carbonitrides in the weld zone and the welding heat-affected zone will decrease the mechanical properties and corrosion resistance;
[0009] (4) Austenitic stainless steel has low thermal conductivity and large linear expansion coefficient, and is prone to large deformation after welding
When the above problems occur in the high-nitrogen steel welded joints, the mechanical properties and corrosion resistance of the joints will decrease accordingly.

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0032] Using high nitrogen steel with a size of 3mm×50mm×50mm as the base material, 80μm×50mm×50mm Fe 75 B 15 Si 10 Nb 1 The amorphous alloy foil is used as the intermediate layer for the instantaneous supercooled liquid phase diffusion welding process.

[0033] Specific steps are as follows:

[0034] 1) Before welding, use sandpaper to clean the surface to be welded of high nitrogen steel, remove the oxide film and oil stain on the surface, and obtain a connection surface with better roughness;

[0035] 2) The base metal and the amorphous alloy are stacked in sequence, and placed in a vacuum hot-press furnace for welding. When the vacuum degree of the vacuum hot pressing furnace reaches 1×10 -2 When the temperature is Pa, the hot-press furnace starts heating. During the heating process, keep the welding pressure at 2Mpa, and control the heating rate at 20°C / min. When the temperature in the vacuum hot-press furnace reaches 550°C, keep it warm for 5 minutes for connection,...

Embodiment 2

[0040] Two columnar high-nitrogen steel materials with a diameter of 20mm and a length of 10mm are used as base materials, and Fe 75 B 15 Si 10 Nb 1 Amorphous alloy powder is used as an intermediate layer for instantaneous supercooled liquid phase diffusion welding process.

[0041] Specific steps are as follows:

[0042] 1) Clean the upper and lower planes of the columnar high-nitrogen steel base material with sandpaper to remove the oxide film and oil stain on the surface;

[0043] 2) Fe 75 B 15 Si 10 Nb 1 The amorphous alloy powder is coated on the surface to be welded so that the thickness of the middle layer is 100 μm, and then put into a vacuum hot-press furnace. When the vacuum degree of the vacuum hot pressing furnace reaches 1×10 -2 At Pa, the hot-press furnace starts heating. During the heating process, keep the welding pressure at 2Mpa, and control the heating rate at 20°C / min. When the temperature in the hot-press furnace reaches 550°C, keep it warm for 5 ...

Embodiment 3

[0048] Using high nitrogen steel with a size of 3mm×50mm×50mm as the base material, 80μm×50mm×50mm Fe 50 Ni 30 B 20 The amorphous alloy foil is used as the intermediate layer for the instantaneous supercooled liquid phase diffusion welding process.

[0049] Specific steps are as follows:

[0050] 1) Before welding, use sandpaper to clean the surface to be welded of high nitrogen steel, remove the oxide film and oil stain on the surface, and obtain a connection surface with better roughness;

[0051] 2) The base metal and the amorphous alloy are stacked in sequence, and placed in a vacuum hot-press furnace for welding. When the vacuum degree of the vacuum hot pressing furnace reaches 1×10 -2At Pa, the hot-press furnace starts heating. During the heating process, keep the welding pressure at 2Mpa, and control the heating rate at 20°C / min. When the temperature in the hot-press furnace reaches 650°C, keep it warm for 5 minutes for connection, and then raise the temperature to ...

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Abstract

The invention discloses a welding method for high-nitrogen steel. According to the method, a block amorphous alloy material serves as an interlayer during welding, connection is achieved through the superplasticity of the amorphous material in a supercooled liquid region, then the amorphous layer is diffused into a base material by increasing the temperature, and the welding of metallurgical bonding is achieved. The welding method is particularly suitable for welding among boards. A welded joint which is high in strength and good in forming can be obtained through the welding method, and when amorphous alloy powder of Fe75B15Si10Nb1 serves as an interlayer, the highest tensile strength of the welded joint is up to 780 MPa.

Description

technical field [0001] The invention relates to a welding method for high nitrogen steel, which belongs to the field of metal welding. Background technique [0002] High-nitrogen stainless steel refers to a type of stainless steel whose nitrogen content exceeds its equilibrium solubility at 1600°C and in the atmosphere. Usually, ferritic / martensitic stainless steel with a nitrogen content exceeding 0.08wt% or austenitic stainless steel with a nitrogen content exceeding 0.4wt% Body stainless steel is called high-nitrogen stainless steel, which is a new type of engineering material that is currently booming. According to the type of matrix structure, high nitrogen stainless steel can be divided into three categories: high nitrogen austenitic stainless steel, high nitrogen ferritic / martensitic stainless steel and high nitrogen (austenite + ferrite) duplex stainless steel. [0003] High-nitrogen austenitic stainless steel mainly uses nitrogen to partially or even completely rep...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): B23K20/14B23K20/16B23K20/227B23K20/24B23K103/04
CPCB23K20/14B23K20/16B23K20/227B23K20/24B23K2103/04
Inventor 孔见梁玉龙王克鸿周琦彭勇
Owner NANJING UNIV OF SCI & TECH
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