Method for preventing oxidation in stainless steel welding in low-vacuum environment

Abstract

The invention relates to a method for preventing oxidation in stainless steel welding in a low vacuum environment, which comprises the following steps of: 1) building a titanium metal space on a vacuum welding furnace chassis according to the size of a stainless steel material part to be welded; (2) the stainless steel material part is placed in the titanium metal space; (3) vacuumizing, heating, preserving heat and cooling according to the operation specification of a vacuum welding furnace; and (4) the vacuum welding furnace is opened, the welded stainless steel parts are taken out, and quality inspection is conducted. The method has the beneficial effects that metal titanium is used for adsorbing and degassing, the problem that the stainless steel surface is oxidized and becomes black during welding is solved, the requirement for the vacuum environment is low, and the welding reliability of stainless steel parts is improved. And the titanium metal space can be reused. The production efficiency is improved, and the cost is reduced.

Description

Technical Field

[0001] The invention belongs to the field of stainless steel material welding or vacuum degassing, and relates to anti-oxidation stainless steel welding. Background Art

[0002] In a low vacuum environment (using an oil pump), when stainless steel parts are welded or degassed, the surface will be oxidized and blackened, affecting the appearance of the product. To remove the oxide layer on the surface of stainless steel parts, the welded parts need to be cleaned. The cleaning fluids are all chemical acid or alkali solvents, which are corrosive to the welds, causing weld leakage and affecting product reliability. When stainless steel parts are welded or degassed in a high vacuum environment (using a molecular pump or an ion pump), the surface will not be oxidized, but the vacuum system is complex and the cost is increased.

[0003] Therefore, it is very necessary to weld or degas stainless steel parts in a low vacuum environment (using an oil pump) without oxidation, avoid chemical acid or alkali corrosion, reduce product costs, and improve production efficiency. So far, there is no simple and efficient method to solve the problem of blackening the surface of stainless steel parts during welding or degassing in a low vacuum environment (using an oil pump). Titanium has good gas absorption properties above 650°C, especially for gases such as hydrogen, oxygen, and nitrogen. Therefore, it is feasible to study a method to weld stainless steel in a low vacuum environment using the characteristics of titanium. Summary of the invention

[0004] The present invention aims to solve the problem that the surface of stainless steel parts will be oxidized and blackened when welded in a low vacuum environment (using an oil pump). A method is proposed in which a space made of metal titanium is used in a low vacuum environment to weld stainless steel without being oxidized in a low vacuum environment.

[0005] The technical solution of the present invention is: a method for preventing oxidation of stainless steel welding in a low vacuum environment, 1) building a titanium metal space on the chassis of a vacuum welding furnace according to the size of the stainless steel parts to be welded; 2) Place stainless steel parts into the titanium space; 3) Evacuate, heat up, keep warm and cool down according to the vacuum welding furnace operating procedures; 4) Open the vacuum welding furnace, take out the welded stainless steel parts, and conduct quality inspection.

[0006] Furthermore, the shape of the titanium metal space is made according to the shape of the vacuum welding furnace chassis, which is round or square, and is provided with a cover that can be opened and closed on the top or a door that can be opened and closed on the side. The cover or door is opened to put the stainless steel parts in. After the stainless steel parts are put in, the cover or door is closed.

[0007] Furthermore, the titanium metal space is non-fixedly connected to the chassis of the vacuum welding furnace, and the titanium metal space can be reused after being cleaned and degassed after use.

[0008] The beneficial effects of the present invention are as follows: a. The present invention utilizes the adsorption characteristics of metal titanium to build a space surrounded by titanium, which effectively solves the problem that the surface of stainless steel parts will be oxidized and blackened during welding or degassing in a low vacuum environment. The vacuum environment requirements are low, and the reliability of welding of stainless steel parts is increased. The titanium metal space can be reused and can be used again after multiple uses only by cleaning.

[0009] b. The process selection of the present invention is flexible, and the implementation method is simple and practical, which greatly improves the production efficiency and reduces the cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a schematic diagram of the structure of the present invention; 1- Vacuum chamber of vacuum welding furnace, 2- Vacuum welding furnace chassis, 3- Titanium metal space. DETAILED DESCRIPTION

[0011] 1) According to the size of the stainless steel parts to be welded, a space surrounded by titanium metal is built on the chassis of the vacuum welding furnace; 2) Place stainless steel parts into the titanium space; 3) Evacuate, heat up, keep warm and cool down according to the vacuum welding furnace operating procedures; 4) Open the vacuum welding furnace, take out the welded stainless steel parts, and conduct quality inspection, such as air tightness test.

[0012] The shape of the titanium metal space is made according to the shape of the vacuum welding furnace chassis, which is generally round or square, and is equipped with a top-openable cover (applicable to vacuum welding furnaces with vacuum chambers that open on the top) or a side-openable door (applicable to vacuum welding furnaces with vacuum chambers that open on the sides). The cover or door is opened to put stainless steel parts in. After the stainless steel parts are put in, the cover or door is closed.

[0013] The titanium metal space is not fixedly connected to the chassis of the vacuum welding furnace. After the titanium metal space is used, it is taken out and reused after cleaning and degassing.

Claims

1. A method for preventing oxidation of stainless steel welding in a low vacuum environment, characterized in that: 1) According to the size of the stainless steel parts to be welded, build a titanium metal space on the chassis of the vacuum welding furnace; 2) Place stainless steel parts into the titanium space; 3) Evacuate, heat up, keep warm and cool down according to the vacuum welding furnace operating procedures; 4) Open the vacuum welding furnace, take out the welded stainless steel parts, and conduct quality inspection.

2. The method for preventing oxidation of stainless steel welding in a low vacuum environment according to claim 1, characterized in that: The shape of the titanium metal space is made according to the shape of the vacuum welding furnace chassis, which is round or square, and is provided with a cover that can be opened and closed on the top or a door that can be opened and closed on the side. The cover or door is opened to put the stainless steel parts in. After the stainless steel parts are put in, the cover or door is closed.

3. The method for preventing oxidation of stainless steel welding in a low vacuum environment according to claim 1, characterized in that: The titanium metal space is not fixedly connected to the chassis of the vacuum welding furnace. After the titanium metal space is used, it can be reused after cleaning and degassing.

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