Automatic welding method for low-temperature high-manganese steel

Abstract

The invention provides an automatic welding method for low-temperature high-manganese steel, and belongs to the technical field of high-manganese steel welding. The automatic welding method comprises the following steps that (1) the low-temperature high-manganese steel to be in butt joint and a welding material are prepared; wherein the low-temperature high-manganese steel to be butted is not beveled, and the weld gap is 0-1mm; (2) assembling the low-temperature high-manganese steel to be butted on a platform, and fixing the low-temperature high-manganese steel to be butted by adopting a fixing clamp, so that a welding seam is 0-1mm; and (3) an automatic welding method is adopted for conducting single-pass welding on the low-temperature high manganese steel to be in butt joint, and single-face welding and double-face forming are achieved. Automatic welding of the low-temperature high-manganese steel is achieved through the single-face welding and double-face forming welding method, reverse buckling operation is reduced, the operation efficiency is improved, meanwhile, the welding quality of the low-temperature high-manganese steel is improved, and environmental pollution is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of high manganese steel welding, and in particular relates to an automatic welding method for low-temperature high manganese steel. Background Art

[0002] The performance of low-temperature high manganese steel is basically the same as that of stainless steel, and it can replace stainless steel in the construction of LNG storage tanks. Therefore, many LNG storage tanks now use low-temperature high manganese steel to reduce construction costs.

[0003] At present, the more stable welding method for low-temperature high-manganese steel is manual arc welding, whose groove form is generally V-shaped or X-shaped groove. The welding method is to weld one side, then planer and grind the other side before welding. However, manual arc welding uses a multi-layer and multi-pass welding method, which is slow and inefficient. The welding quality is restricted by the welder's level, which easily leads to unstable welding quality. In addition, manual arc welding also has the following problems:

[0004] Low temperature high manganese steel adopts multi-layer and multi-pass welding, which generates a large amount of overall welding heat, is prone to deformation, and will affect the mechanical properties of the weld joint;

[0005] Manual arc welding of low-temperature high-manganese steel requires double-sided welding, and the weld needs to be gouged, which will produce smoke and dust, which is harmful to the environment and health;

[0006] Low-temperature high-manganese steel is welded manually, which requires beveling and consumes manpower and material resources.

[0007] Automatic welding of low-temperature high-manganese steel is gradually emerging. CN 115971615 A ​​discloses a fully automatic welding process for high-manganese austenitic steel suitable for LNG storage tanks, which uses high-manganese austenitic steel to melt extremely inert gas shielded welding for base welding, fully automatic submerged arc welding for filling and fully automatic submerged arc welding for covering, and its groove forms include V-shaped grooves and X-shaped grooves. The welding process parameters of the shielded welding base welding are: welding current 140-150A, arc voltage 18-19V, welding speed 400-600mm / min; gas flow 15-20mL / min; base welding 2-4 passes. Fully automatic submerged arc welding filling: welding current 400-460A, arc voltage 29-33V, welding speed 450-550mm / min, fully automatic submerged arc welding filling 10-30 passes. Fully automatic submerged arc welding capping: welding current 360-400A: arc voltage 25-28V, welding speed 360-400mm / min. Fully automatic submerged arc welding capping 3-4 passes. This welding process can automatically and efficiently weld, can weld long straight seams in flat welding positions, has good comprehensive mechanical properties, does not require slag removal at the root of the LNG tank, has good back-forming of the weld, and has excellent welding quality on the back of the weld. However, this fully automatic welding method still requires beveling, and there are problems such as complex welding process and a large number of welding passes. Summary of the invention

[0008] The embodiment of the present invention provides an automatic welding method for low-temperature high manganese steel, which adopts a single-sided welding and double-sided forming welding method to realize automatic welding of low-temperature high manganese steel, reduce back-threading operations, improve operating efficiency, and at the same time improve the welding quality of low-temperature high manganese steel and reduce environmental pollution.

[0009] In order to achieve the above object, the present invention adopts the following technical solutions.

[0010] An automatic welding method for low-temperature high-manganese steel, the automatic welding method comprising the following steps:

[0011] 1) preparing low-temperature high manganese steel to be butted (or welded); wherein the low-temperature high manganese steel to be butted is not grooved, and the weld is 0 to 1 mm (i.e., the groove angle is 0°, and the groove gap is 0 to 1 mm);

[0012] 2) Assemble the low-temperature high manganese steel to be butted on the platform, and fix the low-temperature high manganese steel to be butted with a fixing fixture so that the weld is 0-1 mm; fix the slide rail on the platform, roll-connect the welding trolley with the slide rail, and equip the welding trolley with a welding gun, and place the welding gun at the weld position, so that the welding trolley, the slide rail and the welding gun are assembled in place;

[0013] 3) An automatic welding method is used to perform single-pass welding on the butted low-temperature high-manganese steel to achieve single-sided welding and double-sided forming.

[0014] As an optional implementation, the thickness of the low-temperature high manganese steel is 3 to 12 mm (eg, 5 mm or 10 mm).

[0015] As an optional implementation, the automatic welding method includes deep penetration argon arc welding (ie, K-TIG welding method).

[0016] Deep penetration argon arc welding (K-TIG / DP TIG) is a new type of method that can achieve "Keyhole" welding. Its welding mechanism is that the base metal vaporizes under the action of high-temperature arc, and the generated metal vapor leaves the molten pool at a certain speed. The escape of metal vapor produces a reaction force on the molten liquid metal, which works together with the arc pressure to make the metal surface of the molten pool concave downward, forming a small pit, and the molten metal is squeezed to the surrounding of the molten pool. This process continues, and a keyhole is formed in the liquid metal through the dynamic balance between the surface tension of the molten pool metal and the arc pressure. Deep penetration argon arc welding mainly relies on the arc force formed by the current and the static pressure and surface tension of the liquid metal to maintain the dynamic balance of the molten pool.

[0017] As an optional implementation, the automatic welding method uses a welding carriage for welding.

[0018] As an optional implementation, the step 2) further includes the following steps:

[0019] The slide rail is fixed on the platform, the welding carriage is connected to the slide rail by rolling, a welding gun is arranged on the welding carriage, and the welding gun is placed at the welding seam position, so that the welding carriage, the slide rail and the welding gun are assembled in place.

[0020] As an optional implementation, in the step 3), a welding gun on a welding trolley is used to perform single-pass welding on the weld seam of the low-temperature high manganese steel workpieces to be butted. During the welding process, the welding trolley rolls and moves on the slide rail, thereby driving the welding gun to move along the extension direction of the weld seam, thereby realizing automatic welding of the low-temperature high manganese steel workpieces.

[0021] As an optional implementation, in the automatic welding method, welding wire is not filled during the single-pass welding process.

[0022] As an optional implementation, the automatic welding method performs welding in an inert gas protective atmosphere, and preferably, the inert gas is argon.

[0023] As an optional embodiment, the automatic welding method does not require back-planing.

[0024] As an optional implementation, in the automatic welding method, the welding current is 460-480A (for example, 470A), and the welding voltage is 26-28V (for example, 27V).

[0025] In the present invention, by controlling the welding current and welding voltage, the low-temperature high-manganese steel is melted at a suitable high temperature, which is beneficial to controlling the dynamic balance between the surface tension of the molten pool metal and the arc pressure, thereby facilitating the formation of a keyhole in the liquid metal. Furthermore, by controlling the welding speed, it is beneficial to ensure the forming speed of the liquid metal in the weld and ensure the welding quality.

[0026] As an optional implementation, in the automatic welding method, the welding speed is 250-300 mm / min (for example, 260 mm / min or 280 mm / min).

[0027] The present invention designs a reasonable weld for butting low-temperature high manganese steel, does not open a groove on the low-temperature high manganese steel to be welded (or butted), adopts a small weld, provides small hole welding conditions for the low-temperature high manganese steel, and then adopts a deep-melting argon arc welding method. By designing a reasonable welding current, voltage and welding speed, the dynamic balance of the molten pool is maintained by relying on the arc force formed by the current in the deep-melting argon arc welding process and the static pressure and surface tension of the liquid metal, so that the low-temperature high manganese steel forms a keyhole structure in the weld during a single-pass welding process, thereby achieving a welding effect of single-sided welding and double-sided forming.

[0028] In addition, since the present invention does not use welding wire (or welding material) in the low-temperature high manganese steel welding process, it relies on the melting effect of the high-temperature arc on the low-temperature high manganese steel substrate itself, and realizes the welding (or docking) of two pieces of low-temperature high manganese steel through molten liquid metal. It has good compatibility and is beneficial to improving the welding quality of low-temperature high manganese steel. There is no welding quality problem caused by the compatibility problem between the substrate to be welded and the welding material when other welding materials are selected.

[0029] In the present invention, the above technical features can be freely combined to form a new technical solution without conflicting with each other.

[0030] The beneficial effects brought by the present invention are as follows:

[0031] (1) It can be seen from the above scheme that an embodiment of the present invention provides an automatic welding method for low-temperature high-manganese steel. The welding method adopts deep-melting argon arc welding to achieve single-sided welding and double-sided forming automatic welding of low-temperature high-manganese steel without groove opening and with a weld gap of 0 to 1 mm (for example, 0.1 mm, 0.2 mm, 0.5 mm, 0.6 mm or 0.8 mm), thereby improving welding efficiency and welding quality;

[0032] (2) The automatic welding method for low-temperature high manganese steel of the present invention is used to realize one-step forming of the weld of low-temperature high manganese steel plates with a thickness of 3 to 12 mm, thereby solving the problem of large overall heat quantity of high manganese steel, reducing the number of weld filling layers, and improving the mechanical properties of the weld joint;

[0033] (3) The automatic welding method for low-temperature high manganese steel of the present invention eliminates the need for back-planing, reduces back-threading operations, improves operating efficiency, improves the welding quality of low-temperature high manganese steel, reduces environmental pollution, saves manpower and material resources, and saves production costs; ensures the construction quality of ships under construction, and has won unanimous praise from shipowners and ship inspectors. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 A schematic diagram showing the groove structure of low temperature high manganese steel in Example 1 of the present invention;

[0035] Figure 2 A schematic diagram showing the structure of a low-temperature high-manganese steel workpiece before welding in Example 1 of the present invention;

[0036] Figure 3 A schematic diagram showing the structure of a low-temperature high-manganese steel workpiece during welding in Example 1 of the present invention.

[0037] Figure 4 A schematic diagram showing the groove structure of the low-temperature high manganese steel in Comparative Example 1 of the present invention.

[0038] Figure 5 A schematic diagram showing the welding process of low temperature high manganese steel in comparative example 1 of the present invention. DETAILED DESCRIPTION

[0039] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution in the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiment of the present invention. Obviously, the described embodiment is a part of the embodiment of the present invention, not all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0040] Example 1

[0041] A welding method for low temperature high manganese steel, such as Figure 1 As shown, the following steps are included:

[0042] S1: prepare the low-temperature high manganese steel workpiece to be butted; wherein, when welding the low-temperature high manganese steel workpiece, no groove is opened, or the groove angle is 0°, and the weld (i.e., groove gap) is 0 to 1 mm. Figure 1 As shown;

[0043] S2: According to Figure 1 The structure shown in the figure assembles two low-temperature high-manganese steel workpieces to be butted on a platform and fixes them with a fixing fixture so that the weld is 0 to 1 mm; fixes the slide rail on the platform, rolls the welding trolley and the slide rail together, and arranges a welding gun on the welding trolley. The welding gun is placed at the weld position, and the welding trolley, slide rail, and welding gun are assembled in place. Figure 2 As shown;

[0044] S3: Use the welding gun on the welding carriage to perform single-pass welding on the weld seam of the low-temperature high-manganese steel workpiece to be connected. During the welding process, the welding carriage rolls and moves on the slide rail, thereby driving the welding gun to move along the extension direction of the weld seam to achieve automatic welding of the low-temperature high-manganese steel workpiece. Figure 3 As shown, the specific welding process is as follows:

[0045] The K-TIG welding method is used to weld the low-temperature high manganese steel. The welding process adopts automatic welding by a welding trolley. The welding shielding gas is argon. The weld assembly gap is 0-1mm. No groove is required. The weld is welded in a single pass without using welding wire or back planing. The weld is formed in one time, realizing single-sided welding and double-sided forming. The welding speed is 250-300mm / min. The low-temperature high manganese steel plate thickness applicable to this welding method is 3-12mm.

[0046] Specifically, the welding parameters during the welding process are shown in Table 1.

[0047] Table 1 Welding parameters in Example 1

[0048]

[0049] Example 2

[0050] The difference between this embodiment and embodiment 1 is that the plate thickness is 12 mm, the welding current is 480 A, the welding voltage is 28 V, and the welding speed is 250 cm / min.

[0051] Example 3

[0052] The difference between this embodiment and embodiment 1 is that the plate thickness is 6 mm, the welding current is 480 A, the welding voltage is 28 V, and the welding speed is 250 cm / min.

[0053] Example 4

[0054] The difference between this embodiment and embodiment 1 is that the plate thickness is 3 mm, the welding current is 460 A, the welding voltage is 26 V, and the welding speed is 250 cm / min.

[0055] Comparative Example 1

[0056] A conventional welding method for low temperature high manganese steel comprises the following steps:

[0057] (1) Prepare low-temperature high-manganese steel base material and welding materials; the welding groove of the base material is V-shaped, the groove angle is 60°, and the groove gap is 0-3mm. Figure 4 As shown;

[0058] (2) Manual arc welding is used to weld low-temperature high-manganese steel. After one side is welded (front side welding), the other side is planed and polished before welding (i.e., back side welding). The specific welding method is as follows: Figure 5 As shown. Among them, the welding process parameters are as follows:

[0059] The welding current is 100-140A, the arc voltage is 20-25V, the welding speed is 12-17cm / min, and the welding heat input is 8-16kJ / cm; the interlayer temperature is ≤100℃, and the root cleaning is carried out before the reverse side welding.

[0060] The above are preferred embodiments of the present invention. It should be pointed out that, for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. An automatic welding method for low temperature high manganese steel, characterized in that: The automatic welding method comprises the following steps: 1) preparing low-temperature high manganese steel and welding materials to be butted; wherein the low-temperature high manganese steel to be butted is not grooved, and the weld gap is 0 to 1 mm; 2) Assembling the low-temperature high manganese steel to be butted on the platform, and fixing the low-temperature high manganese steel to be butted with a fixing fixture so that the weld is 0 to 1 mm; 3) An automatic welding method is used to perform single-pass welding on the low-temperature high-manganese steel to be butted, so as to achieve single-sided welding and double-sided forming.

2. The automatic welding method of low temperature high manganese steel according to claim 1, characterized in that: The thickness of the low-temperature high manganese steel is 3 to 12 mm.

3. The automatic welding method of low temperature high manganese steel according to claim 2, characterized in that: The automatic welding method includes deep penetration argon arc welding.

4. The automatic welding method of low temperature high manganese steel according to claim 3, characterized in that: In the automatic welding method, no welding wire is filled during the single-pass welding process.

5. The automatic welding method for low temperature high manganese steel according to any one of claims 1 to 4, characterized in that: The automatic welding method adopts a welding carriage to perform automatic welding.

6. The automatic welding method of low temperature high manganese steel according to claim 5, characterized in that: The step 2) also includes the following steps: The slide rail is fixed on the platform, the welding carriage is connected to the slide rail by rolling, a welding gun is arranged on the welding carriage, and the welding gun is placed at the welding seam position, so that the welding carriage, the slide rail and the welding gun are assembled in place.

7. The automatic welding method of low temperature high manganese steel according to claim 6, characterized in that: In the step 3), a welding gun on a welding carriage is used to perform single-pass welding on the weld seam of the low-temperature high-manganese steel workpieces to be butted. During the welding process, the welding carriage rolls and moves on the slide rail, thereby driving the welding gun to move along the extension direction of the weld seam, thereby realizing automatic welding of the low-temperature high-manganese steel workpieces.

8. The automatic welding method of low temperature high manganese steel according to claim 7, characterized in that: The automatic welding method performs welding in an inert gas protection atmosphere.

9. The automatic welding method for low temperature high manganese steel according to any one of claims 1 to 4, characterized in that: In the automatic welding method, the welding current is 460-480A, the welding voltage is 26-28V, and the welding speed is 250-300mm / min.

10. The automatic welding method of low temperature high manganese steel according to claim 7 or 8, characterized in that: In the automatic welding method, the welding current is 460-480A, the welding voltage is 26-28V, and the welding speed is 250-300mm / min.

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