Welding method of chromium-nickel austenitic stainless steel
By polishing and cleaning the chromicopa -austenite stainless steel welding surface, combined with the technical means of solid welding and full -fledon arc welding, the problem of deformation and bubble formation during welding is solved, which improves the intensity and stability of the welding surface, reduces the strength and stability of the welding surface, reduces the intensity and stability of the welding surface, reduced Risk of break.
Patent Information
- Application Number
- CN202310888800.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-07-19
- Publication Date
- 2025-01-21
AI Technical Summary
Chromium-nickel austenitic stainless steel is prone to deform during welding, and bubbles are easily formed on the welding surface, resulting in brittle and easy to break, posing safety hazards.
By polishing the welding surface, clean up the oil and oxide film, remove the water in the box, and use the combination method of point solid welding and full -length arc welding to control the welding current and voltage to ensure the single -sided welding double -sided forming of the weld.
Reduce the deformation of the welding area, prevent the formation of bubbles, increase the strength of the welding surface, reduce the risk of fracture, and enhance the stability and safety of welding.
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of stainless steel welding, and in particular relates to a welding method for chromium-nickel austenitic stainless steel. Background Art
[0002] Stainless steel refers to steel that is resistant to corrosion by weak corrosive media such as air, steam, and water, and chemically corrosive media such as acids, alkalis, and salts. It is also called stainless acid-resistant steel and is a common and commonly used material in modern people's lives. Chromium-nickel austenitic stainless steel is widely welcomed by people for its good corrosion resistance, high hardness, and high mechanical strength. Chromium-nickel austenitic stainless steel is mainly used in bridges, roads, etc. However, chromium-nickel austenitic stainless steel is easy to deform during welding, and bubbles are easily formed on the welding surface, making the welding surface brittle and easy to break. It brings great safety hazards to construction projects. Summary of the invention
[0003] The invention provides a chromium-nickel austenitic stainless steel welding method for solving the technical problems that the chromium-nickel austenitic stainless steel is easily deformed during welding, bubbles are easily formed on the welding surface, and the welding surface is brittle and easily broken.
[0004] In order to achieve the above object, the present invention is implemented by the following technical scheme: A welding method of chromium-nickel austenitic stainless steel comprises the following steps:
[0005] S1. Polishing and grinding the welding surfaces of two austenitic stainless steels to be welded by a grinding piece so that the surface roughness of the welding surface is 1.0 to 2.2 μm;
[0006] S2, cleaning the oil stains, impurities and oxide film on the welding surface of the austenitic stainless steel to be welded;
[0007] S3, cleaning the surface impurities and oxide film of the welding rod, and placing the welding rod in a drying oven at 200° C. to 250° C. for 1 hour to remove moisture from the welding rod;
[0008] S4, butting the welding surfaces of the two austenitic stainless steels to be welded, and spot welding the welds of the two austenitic stainless steels after being butted, using a welding rod with a diameter of 1.6 mm and a welding current of 90 to 150 A during the spot welding process;
[0009] S5. The two welds of the austenitic stainless steel are manually welded with full argon arc welding. The tungsten electrode of the welding gun nozzle adopts a cerium tungsten electrode with a diameter of 1.6-2.8 mm and a tungsten electrode extension length of 10-12 mm. During argon arc welding, a welding rod with a diameter of 2.0 mm is used. The base current of the welding current is 25-20 A, the peak current is 50-80 A, the welding arc voltage is 20-30 V, and the purity of the argon gas is maintained above 99.98%.
[0010] Optionally, in S2 and S3, the two austenitic stainless steel surfaces to be welded are cleaned with acetone and 15% to 20% sulfuric acid by mass, and the welding rod is immersed in a 5% to 10% sodium hydroxide solution by mass for 45 to 60 seconds at a temperature of 70°C.
[0011] Optionally, in S4 and S5, when welding the two austenitic stainless steels, the angle between the welding gun and the weld is 80° to 90°.
[0012] Optionally, in S4, when spot welding the weld, the arc breaking method is used, the number of spot welding is not less than 2, and the length of the spot welding point is 4 to 6 mm, so that when the austenitic stainless steel is not aligned correctly, it is easy to disassemble, reassemble and spot weld again.
[0013] Optionally, in S1, when the thickness of the austenitic stainless steel is ≥6 mm, the welding surface of the austenitic stainless steel is chamfered so that the interface between the two austenitic stainless steels after butt-jointing is V-shaped, the V-shaped groove has a pair gap of 2 to 4 mm, an angle of 60° to 70°, and a blunt edge of 2.5 cm to 3.5 cm. In S4 and S5, the welds during spot welding and argon arc welding are both single-sided welded and double-sided formed.
[0014] Optionally, a welding method for chromium-nickel austenitic stainless steel further comprises the following steps:
[0015] S6. Heat treat the welded austenitic stainless steel and grind the welded joints. Check the weld surface for cracks, incomplete penetration, lack of fusion and weld nodules.
[0016] It can be seen from the above technical scheme that the beneficial effect of the welding method of chromium-nickel austenitic stainless steel provided by the present invention is: first, the two austenitic stainless steels to be welded are fixed by spot welding, and then welded by argon arc welding, so as to reduce the deformation of the welding point; by removing the moisture in the welding rod, blisters are prevented from appearing during the welding process. DETAILED DESCRIPTION
[0017] The terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, unless otherwise specified, "plurality" means two or more.
[0018] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.
[0019] Example:
[0020] Chromium-nickel austenitic stainless steel is easy to deform during welding, and bubbles are easily formed on the welding surface, making the welding surface brittle and easy to break, which brings great safety hazards to construction projects.
[0021] In order to solve the above technical problems, the present embodiment provides a welding method for chromium-nickel austenitic stainless steel, comprising the following steps:
[0022] S1. The welding surfaces of the two austenitic stainless steels to be welded are polished and ground by a grinding piece so that the surface roughness of the welding surface is 1.0-2.2 μm. When the thickness of the austenitic stainless steel is less than 6 mm, the groove shape of the two austenitic stainless steels is an I-type groove when they are butt-jointed. The welding surface of the austenitic stainless steel is directly polished and ground to remove the burrs on the welding surface. When the thickness of the austenitic stainless steel is ≥6 mm, the welding surface needs to be chamfered by a grinder so that the groove shape of the two austenitic stainless steels is a V-shaped groove when they are butt-jointed. At the same time, the gap between the V-shaped grooves is 2-4 mm, the angle is 60°-70°, and the blunt edge is 2.5 cm-3.5 cm. When the thickness of the austenitic stainless steel is ≥6 mm, the groove shape can also be U-shaped, Y-shaped, etc.
[0023] S2. Use acetone and 15% to 20% sulfuric acid to clean the oil, impurities and oxide film on the welding surface of the austenitic stainless steel to be welded to improve the stability of the welding quality. The welding surface of the austenitic stainless steel to be welded can also be pickled with 15% to 20% sulfuric acid, 5% to 7% hydrochloric acid and 5% to 7% nitric acid. The temperature during pickling is maintained between 70℃ and 80℃, and the pickling time is generally 20 to 50 minutes to remove the oxide film on the welding surface.
[0024] S3. Clean the surface impurities and oxide film of the welding rod, and place the welding rod in a drying oven at 200℃~250℃ for 1h to remove the moisture in the welding rod. Austenitic stainless steel welding rods are divided into two categories: acidic welding rods with titanium calcium type coating and alkaline welding rods with low hydrogen type coating. Low hydrogen stainless steel welding rods have good thermal cracking resistance, but the molding is not as good as titanium calcium type welding rods, and the corrosion resistance is also poor. Titanium calcium type stainless steel welding rods have good process performance and are used more in production. In the present invention, Cr19Ni10 stainless steel welding rods with titanium calcium type coating, i.e. A102 welding rods, can be used. The A102 welding rod has good mechanical properties and intergranular corrosion resistance when depositing metal, and also has excellent welding process performance and anti-porosity performance, and the coating is resistant to redness and cracking. Under the condition of a temperature of 70℃, the welding rod is placed in a sodium hydroxide solution with a mass fraction of 5% to 10% and soaked for 45 to 60S. The purpose of drying the welding rod in a drying oven at 200℃~250℃ for 1 hour is to remove moisture from the welding rod coating and reduce or eliminate the damage to the weld metal.
[0025] S4, butt the two welding surfaces of the austenitic stainless steel to be welded, and spot weld the welds of the two austenitic stainless steels after butt welding. When spot welding, use a welding rod with a diameter of 1.6mm, a welding current of 90-150A, a welding voltage of 20-24V, and a spot welding penetration of ≤0.8mm. When spot welding, use the arc breaking method. The arc breaking method is a single-sided welding and double-sided forming technology that controls the shape of the molten pool, the temperature of the molten pool, and the thickness of the liquid metal in the molten pool by controlling the continuous burning and arc extinguishing time of the arc and the rod movement. The number of spot welding is not less than 2, and the length of the spot welding point is 4-6mm, so that when the welding alignment is incorrect, it is easy to disassemble, reassemble and spot weld again.
[0026] S5. Perform manual full argon arc welding on the welds of the two austenitic stainless steels. During welding, the tungsten electrode of the welding gun nozzle adopts a cerium tungsten electrode. The diameter of the cerium tungsten electrode is 1.6-2.8 mm, and the tungsten electrode protrusion length is 10-12 mm. During argon arc welding, a welding rod with a diameter of 2.0 mm is used, the base current of the welding current is 25-20A, the peak current is 50-80A, the welding arc voltage is 20-30V, and the purity of the argon gas is maintained at more than 99.98%. When welding the two austenitic stainless steels, the angle between the welding gun and the weld is 80°-90°. The welds during spot welding and argon arc welding are both single-sided and double-sided.
[0027] S6. Heat treat the welded austenitic stainless steel and grind the welded joints. Check the weld surface for cracks, incomplete penetration, incomplete fusion and weld nodules. The post-weld heat treatment process for stainless steel can be either single high-temperature tempering or normalizing plus high-temperature tempering. Post-weld heat treatment can eliminate the residual stress of stainless steel relaxation welding; stabilize the shape and size of the structure, reduce distortion; improve the plasticity of the weld metal; improve fatigue strength; improve the ability to resist stress corrosion; and prevent the occurrence of delayed cracks.
[0028] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope of the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.
Claims
1. A welding method for chromium-nickel austenitic stainless steel, characterized in that: The following steps are involved: S1. Polishing and grinding the welding surfaces of two austenitic stainless steels to be welded by a grinding piece so that the surface roughness of the welding surface is 1.0 to 2.2 μm; S2, cleaning the oil stains, impurities and oxide film on the welding surface of the austenitic stainless steel to be welded; S3, cleaning the surface impurities and oxide film of the welding rod, and drying the welding rod in a drying oven at 200° C. to 250° C. for 1 hour to remove moisture from the welding rod; S4, butting the welding surfaces of the two austenitic stainless steels to be welded, and spot welding the welds of the two austenitic stainless steels after butting. During the spot welding, a welding rod with a diameter of 1.6 mm is used, a welding current of 90 to 150 A, and a welding voltage of 20 to 24 V is used; S5. The two welds of the austenitic stainless steel are manually welded with full argon arc welding. The tungsten electrode of the welding gun nozzle adopts a cerium tungsten electrode with a diameter of 1.6-2.8 mm and a tungsten electrode extension length of 10-12 mm. During argon arc welding, a welding rod with a diameter of 2.0 mm is used. The base current of the welding current is 25-20 A, the peak current is 50-80 A, the welding arc voltage is 20-30 V, and the purity of the argon gas is maintained above 99.98%.
2. A method for welding chromium-nickel austenitic stainless steel according to claim 1, characterized in that: In S2 and S3, the two austenitic stainless steel surfaces to be welded are cleaned with acetone and 15% to 20% sulfuric acid by mass, and the welding rod is immersed in a 5% to 10% sodium hydroxide solution by mass for 45 to 60 seconds at a temperature of 70°C.
3. The welding method of chromium-nickel austenitic stainless steel according to claim 1, characterized in that: In S4 and S5, when welding the two austenitic stainless steels, the angle between the welding gun and the weld is 80° to 90°.
4. The welding method of chromium-nickel austenitic stainless steel according to claim 1, characterized in that: In S4, when spot welding the weld, the arc breaking method is used, the number of spot welding is not less than 2, and the length of the spot welding point is 4 to 6 mm, so that when the austenitic stainless steel is not aligned correctly, it is easy to disassemble, reassemble and spot weld again.
5. The welding method of chromium-nickel austenitic stainless steel according to claim 1, characterized in that: In S1, when the thickness of the austenitic stainless steel is ≥6 mm, the welding surface of the austenitic stainless steel is chamfered so that the interface of the two austenitic stainless steels after butt joint is V-shaped, the gap between the V-shaped grooves is 2 to 4 mm, the angle is 60° to 70°, and the blunt edge is 2.5 cm to 3.5 cm. In S4 and S5, the welds during spot welding and argon arc welding are both single-sided welded and double-sided formed.
6. The welding method of chromium-nickel austenitic stainless steel according to claim 1, characterized in that: The following steps are also included: S6. Heat treat the welded austenitic stainless steel and grind the welded joints. Check the weld surface for cracks, incomplete penetration, lack of fusion and weld nodules.