Process evaluation device and process evaluation method for butt welding of stainless steel and low alloy steel

Abstract

The invention discloses a stainless steel and low alloy steel butt welding process evaluation device and process evaluation method.The stainless steel and low alloy steel butt welding process evaluation device comprises a structural part protection part, a heat preservation cotton plate and a horizontal placement part, protection cotton is arranged in the structural part protection part, and the horizontal placement part is arranged on the structural part protection part; the two welding materials are horizontally placed on the upper portion of the structural part protection part through the horizontal placing part, a welding groove is formed between the two welding materials, the heat preservation cotton plate is correspondingly arranged under the welding groove, and the structural part protection part is provided with a shielding gas assembly corresponding to the welding groove. The structure protection part of the box body structure is arranged, the stainless steel plate and the low-alloy steel plate are horizontally arranged on the structure protection part through the horizontal placement part, heat preservation or shielding gas protection on the welding position is achieved through the heat preservation cotton plate and the shielding gas assembly based on the welding process to be evaluated, and therefore process evaluation is facilitated; by means of the process evaluation method, the operation cost of follow-up actual welding can be greatly reduced, and guarantee is provided for engineering construction.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of welding process evaluation, in particular to a stainless steel and low alloy steel butt welding process evaluation device and method. BACKGROUND

[0002] In the welding professional block, large structural parts, oil pipelines and pressure equipment often need to be manufactured by welding, especially in the design of large spare parts for special equipment, there are welding operations of the same metal connection, different metal connection and other machining positions on the same equipment, such as: base material cast steel ZG35Cr24Ni7SiN + base material cast steel ZG35Cr24Ni7SiN welding of the same material; base material cast steel ZG35Cr24Ni7SiN + stainless steel 06Cr25Ni20 welding of different materials; base material cast steel ZG35Cr24Ni7SiN + low alloy steel Q355 welding of different materials; base material stainless steel 06Cr25Ni20 + low alloy steel Q355 welding of different materials; base material low carbon steel Q235 + low alloy steel Q355 welding of different materials, etc.

[0003] When welding different metals of stainless steel and low alloy steel on the equipment, a large number of welding equipment and welding materials need to be purchased to meet the welding requirements of different metal connection materials, which occupies a large area, has complex process and high cost, and welding defects are easy to occur when welding directly, so that the welding quality cannot be guaranteed.

[0004] In view of the above defects, the present application creator finally obtains the present application after a long time of research and practice. SUMMARY

[0005] In order to solve the above technical defects, the technical scheme adopted by the present application is to provide a stainless steel and low alloy steel butt welding process evaluation device, which comprises a structural part protection part, a heat preservation cotton board and a horizontal placement part, the structural part protection part is provided as an open-ended rectangular box structure, the protection cotton is arranged in the structural part protection part, the horizontal placement part is arranged on the structural part protection part, two welding materials are horizontally placed on the upper part of the structural part protection part through the horizontal placement part, a welding groove is formed between the two welding materials, the heat preservation cotton board is correspondingly arranged below the welding groove, the structural part protection part is provided with a protection gas assembly corresponding to the welding groove, and the two welding materials are respectively stainless steel plate and low alloy steel plate.

[0006] Preferably, the protection gas assembly comprises a protection gas inlet hole and a protection gas conveying pipeline, the protection gas inlet hole is arranged on the structural part protection part, the protection gas inlet hole is arranged below the welding groove, and the protection gas inlet hole is connected with the protection gas conveying pipeline.

[0007] Preferably, the structure protection part comprises a bottom plate, two first side plates and two second side plates, the two first side plates are arranged in parallel, the two second side plates are arranged in parallel, and the first side plates and the second side plates are both fixed vertically on the bottom plate, and the first side plates and the second side plates alternately surround to form a rectangular frame structure.

[0008] Preferably, the height of the first side plate is greater than the height of the second side plate, and the two first side plates are arranged on both sides of the stainless steel plate and the low alloy steel plate.

[0009] Preferably, the horizontal placement part comprises two horizontal support plates, the two horizontal support plates are arranged on the same horizontal plane, and the two horizontal support plates are respectively fixed on the two second side plates, the horizontal support plates are arranged on the upper end of the second side plates, and the horizontal support plates on the two second side plates correspondingly support the stainless steel plate and the low alloy steel plate.

[0010] Preferably, the stainless steel plate and the low alloy steel plate are both arranged as flat plates, one side of the stainless steel plate and the low alloy steel plate is provided with a single-bevel groove, and the single-bevel groove of the stainless steel plate and the low alloy steel plate forms the welding groove.

[0011] Preferably, the single-bevel groove is arranged as a 30° inclined groove, the cross section of the welding groove is Y-shaped as a whole, and the upper part of the welding groove is formed as a V-shaped groove with an angle of 60° by the two single-bevel grooves.

[0012] Preferably, a process qualification method for butt welding of stainless steel and low alloy steel adopts a process qualification device for butt welding of stainless steel and low alloy steel, and comprises the following steps:

[0013] S1, preparation before welding;

[0014] S2, welding process route;

[0015] In the step S2, the welding process route is:

[0016] The structure protection part is installed, the protection gas conveying pipeline is inserted into the structure protection part in advance, the heat insulation cotton plate is placed in the structure protection part, and the stainless steel plate and the low alloy steel plate are arranged in pairs and placed horizontally on the horizontal placement part.

[0017] The welding groove is cleaned, and the single-sided groove on both sides is preheated by 100° to 120°; the weld includes a bottom layer, a filling layer and a cover layer from bottom to top. ERNiCrMo-3 welding wire is used for welding the weld. The welding of the bottom layer adopts a straight wire feeding method, and the welding of the filling layer and the cover layer adopts a crescent wire feeding method. The interlayer temperature is maintained during the welding process, and local welding stress is eliminated by hammering and each layer is cleaned. After the cover layer is welded, the weld is track-tempered by 300°. After the weld cools to room temperature, X-ray flaw detection and mechanical property testing are performed, and finally it is delivered for use in the formulated welding process.

[0018] Compared with the prior art, the beneficial effect of the present invention is that: the present invention arranges the structural protection part of the box structure, horizontally arranges the stainless steel plate and the low-alloy steel plate on the structural protection part through the horizontal placement part, and based on the welding process to be evaluated, the insulation cotton board and the protective gas component are used to achieve insulation or protective gas protection at the welding position, thereby facilitating process evaluation. The process evaluation of the present invention can greatly reduce the operating cost of subsequent actual welding, providing protection for engineering construction. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A structural stereoscopic view of the process evaluation device for butt welding of stainless steel and low alloy steel;

[0020] Figure 2 An exploded view of the structure of the process qualification device for butt welding of stainless steel and low alloy steel;

[0021] Figure 3 Schematic diagram of the weld seam of the butt welding of stainless steel and low alloy steel.

[0022] The numbers in the figure represent:

[0023] 1-stainless steel plate; 2-low alloy steel plate; 3-weld; 4-single-side bevel; 5-structural component protection part; 6-shielding gas inlet hole; 7-shielding gas delivery pipeline; 8-insulation cotton board; 9-horizontal placement part; 31-bottom layer; 32-first filling layer; 33-second filling layer; 34-covering layer. DETAILED DESCRIPTION

[0024] The above and other technical features and advantages of the present invention are described in more detail below with reference to the accompanying drawings.

[0025] Example 1

[0026] like Figure 1 、 Figure 2 As shown, Figure 1 A structural stereoscopic view of the process evaluation device for butt welding of stainless steel and low alloy steel; Figure 2It is a structural exploded view of the process qualification device for butt welding of stainless steel and low alloy steel.

[0027] The process qualification device for butt welding of stainless steel and low alloy steel comprises a structure protection part 5, a heat preservation cotton plate 8 and a horizontal placement part 9, the structure protection part 5 is provided as a long box structure with an open upper end, the protection cotton is arranged in the structure protection part 5, the horizontal placement part is arranged on the structure protection part 5, two welding materials are horizontally placed on the upper part of the structure protection part 5 through the horizontal placement part, a welding groove is formed between the two welding materials, the heat preservation cotton plate 8 is correspondingly arranged directly below the welding groove, the structure protection part 5 is provided with a protective gas assembly corresponding to the welding groove, and the two welding materials are respectively a stainless steel plate 1 and a low alloy steel plate 2.

[0028] Preferably, the protective gas assembly comprises a protective gas inlet hole 6 and a protective gas conveying pipeline 7, the protective gas inlet hole 6 is arranged on the structure protection part 5, the protective gas inlet hole 6 is arranged below the welding groove, and the protective gas inlet hole 6 is connected with the protective gas conveying pipeline 7, so as to introduce welding protective gas into the structure protection part 5, so as to protect the back of the weld 3 from forming at the welding groove.

[0029] Specifically, the structure protection part 5 comprises a bottom plate, two first side plates and two second side plates, the two first side plates are arranged in parallel, the two second side plates are arranged in parallel, and the first side plates and the second side plates are both fixed vertically on the bottom plate, and the first side plates and the second side plates alternately surround to form a rectangular frame structure, and the structure of the structure protection part can form a sealed structure with only the upper end being open, so that the welding position can be heat preserved by the protection cotton, and the welding position can also be gas protected by the protective gas.

[0030] Preferably, the height dimension of the first side plate is greater than that of the second side plate, and the two first side plates are arranged on the two sides of the stainless steel plate 1 and the low alloy steel plate 2 at the same time, so that the stainless steel plate 1 and the low alloy steel plate 2 can be limited in the horizontal direction, so as to further improve the position stability of the stainless steel plate 1 and the low alloy steel plate 2 after alignment.

[0031] The horizontal placement part 9 comprises two horizontal support plates, the two horizontal support plates are arranged on the same horizontal plane, and the two horizontal support plates are fixedly arranged on the two second side plates respectively, the horizontal support plates are correspondingly arranged at the upper ends of the second side plates, and the horizontal support plates on the two second side plates correspondingly support the stainless steel plate 1 and the low alloy steel plate 2 respectively, so as to ensure the alignment stability of the stainless steel plate 1 and the low alloy steel plate 2.

[0032] The stainless steel plate 1 and the low alloy steel plate 2 are both configured as flat plates, and a single-sided bevel 4 is provided on one side of the stainless steel plate 1 and the low alloy steel plate 2. The single-sided bevel 4 of the stainless steel plate 1 and the low alloy steel plate 2 forms the welding groove.

[0033] The single-sided bevel 4 is generally set to a 30° inclined bevel, the cross section of the welding groove is a Y-shaped groove as a whole, and the upper part of the welding groove is formed by two single-sided bevels 4 to form a V-shaped groove with an angle of 60°.

[0034] The present invention sets the structural protection part of the box structure, and horizontally sets the stainless steel plate 1 and the low-alloy steel plate 2 on the structural protection part through the horizontal placement part. Based on the welding process to be evaluated, the insulation cotton plate 8 and the protective gas component can be used to achieve insulation or protective gas protection at the welding position, thereby facilitating process evaluation. It has a novel structure, compact and reasonable configuration, low investment, small site occupation, low operation and maintenance costs, easy operation, and reliable operation.

[0035] Example 2

[0036] In this embodiment, the two welding materials are stainless steel (06CR25NI20) and low alloy steel (Q355), respectively.

[0037] The stainless steel plate 1 is machined from 25 mm and has dimensions of 400 mm in length × 200 mm in width × 25 mm in thickness, and a single-side groove 4 with a 30° angle is machined on the long side.

[0038] The low alloy steel plate 2 is machined from 25 mm and has dimensions of 400 mm in length × 200 mm in width × 25 mm in thickness, and a single-side groove 4 with a 30° angle is machined on the long side.

[0039] The stainless steel plate 1 and the low alloy steel plate 2 are paired to form a Y-shaped welding groove, and then a weld 3 is formed by single-sided welding and double-sided forming.

[0040] The structural member protection portion 5 is machined and welded using a 10 mm diameter machine. The stainless steel plate 1 and the low-alloy steel plate 2 are placed horizontally on the horizontal placement portion 9. The shielding gas delivery pipe 7 is machined from a seamless steel pipe having a diameter of 10 mm and is inserted into the shielding gas inlet hole 6. The delivered argon gas protects the stainless steel plate 1 and the low-alloy steel plate 2 from forming the weld seam 3 on the back surface.

[0041] Connection method: first, the single-sided groove 4 is formed on the stainless steel plate 1 and the low-alloy steel plate 2 by mechanical processing, and then the stainless steel plate 1 and the low-alloy steel plate 2 are paired, and the shielding gas delivery pipe 7 is inserted into the shielding gas inlet hole 6, and the insulation cotton plate 8 is placed in the structural part protection part 5, and then the paired stainless steel plate 1 and the low-alloy steel plate 2 are placed horizontally on the horizontal placement part, and finally the stainless steel plate 1 and the low-alloy steel plate 2 are welded to form a weld 3.

[0042] Example 3

[0043] The process evaluation method for butt welding of stainless steel and low alloy steel of the present invention comprises the following steps:

[0044] S1, preparation before welding;

[0045] S2, welding process route.

[0046] In step S2, the welding process route is:

[0047] Install the structural member protection portion 5 and insert the protective gas delivery pipe 7 into the structural member protection portion 5 and supply gas 2 minutes in advance to fill the structural member protection portion 5 with argon gas for bottom layer welding protection; place the thermal insulation board 8 into the structural member protection portion 5; finally, place the assembled stainless steel plate 1 and low alloy steel plate 2 horizontally on the horizontal placement portion 9;

[0048] The welding groove is cleaned, and the single-sided groove 4 on both sides is preheated by 100° to 120°. The weld 3 includes a bottom layer 31, a filling layer and a cover layer 34 from bottom to top. ERNiCrMo-3 welding wire is used when welding the weld 3. The welding of the bottom layer 31 adopts a straight wire feeding method, and the welding of the filling layer and the cover layer 34 adopts a crescent wire feeding method. During the welding process, the interlayer temperature is maintained, local welding stress is eliminated by hammering, and each layer is cleaned without welding defects. After the welding of the cover layer 34 is completed, the weld 3 is track-tempered by 300°. After the weld 3 cools to room temperature, X-ray flaw detection and mechanical property testing are performed, and finally it is delivered for use in the formulated welding process.

[0049] like Figure 3 As shown, Figure 3 Schematic diagram of the weld 3 of the butt welding of stainless steel and low alloy steel; in this embodiment, the filling layer is provided with two layers, namely a first filling layer 32 and a second filling layer 33.

[0050] In step S2, different welding process parameters are adopted based on different welding processes to achieve process evaluation of the corresponding welding processes.

[0051] The specific contents of the pre-welding preparation in step S1 are as follows:

[0052] Welding equipment: Panasonic YC-400TX4 manual argon arc welding and stick arc welding combined welding machine, Panasonic YD-350FR2 manual carbon dioxide gas shielded welding machine, high purity argon purity 9999.9%. Welding material selection: ERNiCrMo-3 welding wire, φ2.5mm for GTAW argon arc welding, φ1.2mm for MAG gas shielded welding.

[0053] Bottom layer weld protection cooling device: the structure protection part 5 and the heat preservation cotton board 8.

[0054] Auxiliary facilities: angle grinder, file, hammer, flat shovel, mask, template, temperature meter, magnifying glass, heat preservation cotton.

[0055] Welding material: stainless steel plate 1 and low alloy steel plate 2.

[0056] Pre-welding requirements: the welding position area and the welding material should not have oil stains, oxide layers, moisture, etc., and should expose the metal luster. Use oxyacetylene · flame to remove moisture and oil, and then polish rust with sandpaper or grinding machine.

[0057] Welding position: horizontal fixed welding 1G.

[0058] Welding requirements: single-sided welding double-sided forming weld 3, 3 layers of surfacing fusion base material, weld 3 without any welding defects and meet the design size.

[0059] In the embodiment, the specific welding process parameters of the stainless steel and low alloy steel butt welding are selected by the following table.

[0060] Welding process parameter selection table

[0061]

[0062] The specific content of the step S2 is as follows:

[0063] Install the structure protection part 5, insert the protection gas conveying pipeline 7 and send gas 2 minutes in advance, so that the inside of the structure protection part 5 is filled with argon, which is convenient for the bottom layer 31 of the welding groove to be welded, the heat insulation cotton board 8 is placed in the structure protection part 5, and finally the matched stainless steel plate 1 and low alloy steel plate 2 are horizontally placed on the horizontal placement part. The single-sided groove 4 is cleaned, the single-sided groove 4 on both sides is preheated to 100-120 DEG, in order to better reduce the local temperature difference stress, improve the internal organization, prevent or reduce the hardened organization, the temperature verification must be carried out on both sides of the welding seam 3 by using a temperature measuring gun, after the temperature reaches, the bottom layer 31 is welded by using a combination of a Panasonic YC-400TX4 manual argon arc welding and a stick arc welding, a manual tungsten argon arc welding straight line operation method, high-purity argon with a purity of 9999.9%, welding material: ERNiCrMo-3 welding wire, argon arc welding wire φ2.5mm. The horizontal angle between the welding wire and the welding part is 20-45 DEG, the horizontal angle between the welding gun and the welding part is 75-85 DEG, the welding current is 110A-140A, the welding seam 3 is divided into the bottom layer 31, the first filling layer 32, the first filling layer 32 and the cover layer 34 from bottom to top, after the bottom layer 31 is welded by single-sided welding and double-sided forming, the welding seam 3 is cleaned to ensure that there is no welding defect and the welding seam 3 is flat, which is convenient for the filling layer welding, the filling layer and the cover layer 34 are started to be welded by using a YD-350FR2 manual carbon dioxide gas protection welding machine, the gas protection welding wire is φ1.2mm, the welding material is ERNiCrMo-3 welding wire, the interlayer temperature is kept not lower than the preheating temperature, a crescent-shaped operation method is adopted, the welding seam 3 surface is cleaned layer by layer, the welding layer reaches 10mm and must be hammered to further eliminate the local welding stress, after ensuring that there is no any welding defect, the next layer welding is carried out, the cover layer 34 must be higher than the base material, but cannot be >3mm, the welding seam 3 on both sides keeps smooth transition with the base material, after the whole welding is completed, the welding seam 3 area is continuously tracked and heated by using oxyacetylene for 300 DEG constant temperature for 2 hours, then the heat insulation cotton is banded and slowly cooled to room temperature, X-ray detection is carried out on the pressure-bearing container according to JB / T4730-2005, and then the mechanical property detection is carried out according to NB / T47016-2011, the welding performance of the cast steel and the stainless steel completely meets the requirements through the detection effect, and the welding process is delivered for use.

[0064] The present application is aimed at the particularity of butt welding of stainless steel 06CR25NI20 and low alloy steel Q355, a device and process for evaluating butt welding of stainless steel and low alloy steel are developed and implemented. The implementation of the process evaluation method is not only safe and easy to operate, but also has stable welding quality, low investment cost, meets the actual needs of the site, has high work efficiency, greatly reduces the maintenance cost, and provides protection for engineering construction. At the same time, the process evaluation of stainless steel and low alloy steel welding provides a scientific reference for other special type welding.

[0065] The above descriptions are only the preferable embodiments of the present application, which are only illustrative but not restrictive. It is understood by those skilled in the art that many changes, modifications, even equivalences can be made to the present application within the spirit and scope defined by the claims of the present application, and all of them will fall into the protection scope of the present application.

Claims

1. A process evaluation device for butt welding of stainless steel and low alloy steel, characterized in that: It includes a structural part protection part, a thermal insulation cotton board and a horizontal placement part. The structural part protection part is configured as a rectangular box structure with an open upper end. The protective cotton is arranged in the structural part protection part, and the horizontal placement part is arranged on the structural part protection part. Two welding materials are horizontally placed on the upper part of the structural part protection part through the horizontal placement part. A welding groove is formed between the two welding materials. The thermal insulation cotton board is correspondingly arranged directly below the welding groove. The structural part protection part is provided with a shielding gas assembly corresponding to the welding groove. The two welding materials are respectively a stainless steel plate and a low alloy steel plate.

2. The process evaluation device for butt welding of stainless steel and low alloy steel according to claim 1, characterized in that: The shielding gas assembly includes a shielding gas inlet hole and a shielding gas delivery pipeline. The shielding gas inlet hole is arranged on the structural component protection part, the shielding gas inlet hole is arranged corresponding to the bottom of the welding groove, and the shielding gas inlet hole is connected to the shielding gas delivery pipeline.

3. The process evaluation device for butt welding of stainless steel and low alloy steel according to claim 2, characterized in that: The structural member protection portion includes a bottom plate, two first side plates and two second side plates, the two first side plates are arranged in parallel, the two second side plates are arranged in parallel, and the first side plates and the second side plates are both vertically fixed on the bottom plate, and the first side plates and the second side plates are alternately arranged to form a rectangular frame structure.

4. The process evaluation device for butt welding of stainless steel and low alloy steel according to claim 3, characterized in that: The height dimension of the first side plate is greater than the height dimension of the second side plate, and the two first side plates are simultaneously arranged on both sides of the stainless steel plate and the low-alloy steel plate.

5. The process evaluation device for butt welding of stainless steel and low alloy steel as claimed in claim 3, characterized in that: The horizontal placement part includes two horizontal support plates, which are arranged on the same horizontal plane and are respectively fixed on the two second side plates. The horizontal support plates are correspondingly arranged at the upper ends of the second side plates, and the horizontal support plates on the two second side plates respectively support the stainless steel plate and the low alloy steel plate.

6. The process evaluation device for butt welding of stainless steel and low alloy steel as claimed in claim 3, characterized in that: The stainless steel plate and the low alloy steel plate are both configured as flat plates, and one side of each of the stainless steel plate and the low alloy steel plate is provided with a single-sided bevel, and the single-sided bevel of the stainless steel plate and the low alloy steel plate forms the welding groove.

7. The process evaluation device for butt welding of stainless steel and low alloy steel according to claim 6, characterized in that: The single-sided bevel is set to a 30° inclined bevel, the cross-section of the welding groove is a Y-shaped groove as a whole, and the upper part of the welding groove is a V-shaped groove with a 60° angle formed by two single-sided bevels.

8. A process evaluation method for butt welding of stainless steel and low alloy steel, characterized in that: A process assessment device for butt welding of stainless steel and low alloy steel according to any one of claims 2 to 7 comprises the following steps: S1, preparation before welding; S2, welding process route; In step S2, the welding process route is: Install the structural component protection portion and insert the protective gas delivery pipe into the structural component protection portion to supply gas in advance; place the thermal insulation cotton board into the structural component protection portion; and place the aligned stainless steel plate and the low alloy steel plate horizontally on the horizontal placement portion; The welding groove is cleaned, and the single-sided groove on both sides is preheated by 100° to 120°; the weld includes a bottom layer, a filling layer and a cover layer from bottom to top. ERNiCrMo-3 welding wire is used for welding the weld. The welding of the bottom layer adopts a straight wire feeding method, and the welding of the filling layer and the cover layer adopts a crescent wire feeding method. The interlayer temperature is maintained during the welding process, and local welding stress is eliminated by hammering and each layer is cleaned. After the cover layer is welded, the weld is track-tempered by 300°. After the weld cools to room temperature, X-ray flaw detection and mechanical property testing are performed, and finally it is delivered for use in the formulated welding process.

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