阅读说明：本技术 覆土罐罐壁板的焊接方法 (Welding method for tank wall plate of soil covering tank ) 是由 张磊 宁博 陈自振 吴道凡 张坤 李会英 于 2019-10-12 设计创作，主要内容包括：本发明涉及一种覆土罐罐壁板的焊接方法,属于覆土罐技术领域。本发明的覆土罐罐壁板的焊接方法,包括：加工双V型复合坡口；采用混合气体保护焊进行罐壁板的横焊和立上焊；保护气体为二氧化碳与氩气组成的混合气。将该焊接方式与双V型复合坡口、混合气进行结合,能够在保证焊缝质量的前提下,减少焊缝填充量,提高焊接效率,提升30％的综合焊接工效,从而降低了焊接施工成本。下段坡口角度设为42.5°～47.5°,有利于将坡口边缘充分融化,避免出现未熔合,保证焊缝质量,上段坡口面角度设为3.5°～6.5°,有利于减少填充量,降低焊接成本。该混合气有利于获得较大的熔深,保证打底时能够焊透,同时减少焊接飞溅。(The invention relates to a welding method of a tank wall plate of an earth covering tank, and belongs to the technical field of earth covering tanks. The welding method of the tank wall plate of the soil covering tank comprises the following steps: processing a double-V-shaped composite groove; adopting mixed gas shielded welding to perform horizontal welding and vertical up-welding of the tank wall plate; the protective gas is a mixed gas consisting of carbon dioxide and argon. The welding mode is combined with the double-V-shaped composite groove and the mixed gas, so that the filling amount of the welding seam is reduced, the welding efficiency is improved, and the comprehensive welding efficiency is improved by 30% on the premise of ensuring the quality of the welding seam, thereby reducing the welding construction cost. The angle of the lower-section groove is set to be 42.5-47.5 degrees, which is beneficial to fully melting the edge of the groove, avoiding the occurrence of incomplete fusion, ensuring the quality of a welding seam, and the angle of the upper-section groove surface is set to be 3.5-6.5 degrees, which is beneficial to reducing the filling amount and reducing the welding cost. The mixed gas is beneficial to obtaining larger fusion depth, can ensure thorough welding during bottoming, and simultaneously reduces welding spatter.)

1. A welding method for wall plates of an earth covering tank is characterized by comprising the following steps:

(1) processing a double-V-shaped composite groove on a tank wall plate;

the double-V-shaped composite groove comprises a truncated edge, a lower-section groove and an upper-section groove, wherein a groove inflection point is arranged at the joint of the lower-section groove and the upper-section groove, the groove angle of the lower-section groove is 42.5-47.5 degrees, the groove surface angle of the upper-section groove is 3.5-6.5 degrees, the length of the truncated edge is 0.5-1.5 mm, and the distance between the groove inflection point and the bottom edge of a tank wall plate is 4-6 mm;

(2) adopting mixed gas shielded welding to perform horizontal welding and vertical up-welding of the tank wall plate;

the shielding gas adopted by the mixed gas shielded welding is a mixed gas consisting of 75-85 vol% of carbon dioxide and 15-25 vol% of argon.

2. The welding method of the tank wall plate of the soil covering tank as described in claim 1, wherein in the step (1), the bevel angle of the lower groove is 45 °, the bevel face angle of the upper groove is 5 °, the length of the truncated edge is 1mm, and the distance from the corner point of the groove to the bottom edge of the tank wall plate is 5 mm.

3. The welding method of the wall plates of the soil covering tank of claim 1, wherein in the step (1), the assembling process parameters of the double V-shaped composite groove are as follows: the gap of the root of the groove is 2-2.5 mm, and the misalignment is less than 1.5 mm.

4. The method for welding the wall plates of the soil covering tank of claim 1, wherein in the step (1), the machining method for machining the double V-shaped composite groove is mechanical cold machining.

5. The method for welding the wall plates of the soil covering tank as claimed in claim 1, wherein in the step (1), the thickness of the tank wall plate is 12 to 30 mm.

6. The method for welding the wall plates of the soil covering tank as defined in any one of claims 1 to 5, wherein in the step (2), the primer layer, the filling layer and the cover layer are welded in sequence from the bottom of the small end of the double V-shaped composite groove;

the welding current that welding priming layer adopted is 90 ~ 130A, the welding current that welding filling layer adopted is 180 ~ 200A, the welding current that welding capping layer adopted is 180 ~ 200A.

7. The method of welding can panels of an earth-covering can of claim 6, wherein the inter-track temperature of the weld is 150 ℃ or less.

8. The method of welding can walls of an earth-covering can as defined in claim 6, wherein the welding primer layer is formed by a single-side welding and double-side forming technique.

9. The method for welding can walls of a soil covering can according to claim 6, wherein the welding primer layer adopts the following process parameters: the welding current is 90-130A, the voltage is 18-20V, the diameter of a welding wire is 1.2mm, the welding speed is 16-22 cm/min, the wire feeding speed is 80-110 in/min, the elongation of the welding wire is 8-12 mm, and the gas flow is 20-30L/min;

the welding filling layer adopts the following technological parameters: the welding current is 180-200A, the voltage is 23-26V, the diameter of a welding wire is 1.2mm, the welding speed is 18-22 cm/min, the wire feeding speed is 90-110 in/min, the elongation of the welding wire is 8-12 mm, and the gas flow is 20-30L/min;

the welding cover surface layer adopts the following technological parameters: the welding current is 180-200A, the voltage is 23-26V, the diameter of a welding wire is 1.2mm, the welding speed is 14-20 cm/min, the wire feeding speed is 80-100 in/min, the elongation of the welding wire is 8-12 mm, and the gas flow is 20-30L/min.

10. A method of welding can walls of casing pots according to any of claims 1 to 5 where in step (2) the shielding gas used in the MIG welding is a mixture of 75 vol% to 85 vol% carbon dioxide and 15 vol% to 25 vol% argon.

Technical Field

The invention relates to a welding method of a tank wall plate of an earth covering tank, and belongs to the technical field of earth covering tanks.

Background

The earth-covering tank is a storage tank for storing crude oil and product oil, the construction requirement on the earth-covering tank is higher and higher at present, the operation space in the earth-covering tank is narrow and limited, the construction difficulty is high in the limited space, the technical requirement is high, full-automatic submerged arc horizontal welding and gas-electric vertical welding cannot be used due to the limited operation space, most of pipe wall welding of the earth-covering tank adopts welding rod arc welding due to the limited conditions, the construction measures are old, the welding is performed in the limited space, the ventilation is not smooth, smoke and dust are large, the welding environment is poor, a carbon arc gouging plane is needed to be adopted for back gouging, the construction efficiency is influenced, the noise is large, the operation environment is poor, in addition, the using amount of welding materials is large, the welding time is long, the welding cost is high, the construction efficiency is lower, and the.

Disclosure of Invention

The invention aims to provide a welding method of a tank wall plate of an earth covering tank, which is used for welding the tank wall plate of the earth covering tank, is beneficial to saving welding materials, reducing cost and ensuring welding quality.

The technical scheme of the invention is as follows:

(1) processing a double-V-shaped composite groove on a tank wall plate;

the double-V-shaped composite groove comprises a truncated edge, a lower-section groove and an upper-section groove, wherein a groove inflection point is arranged at the joint of the lower-section groove and the upper-section groove, the groove angle of the lower-section groove is 42.5-47.5 degrees, the groove surface angle of the upper-section groove is 3.5-6.5 degrees, the length of the truncated edge is 0.5-1.5 mm, and the distance between the groove inflection point and the bottom edge of a tank wall plate is 4-6 mm;

(2) adopting mixed gas shielded welding to perform horizontal welding and vertical up-welding of the tank wall plate;

the shielding gas adopted by the mixed gas shielded welding is a mixed gas consisting of 75-85 vol% of carbon dioxide and 15-25 vol% of argon.

It can be understood that after the double-V-shaped composite groove is processed on the tank wall plate, the cut surface of the groove is smooth by grinding. So that the groove and the inner and outer surfaces of the tank wall plate within 50mm from the groove are free of rust, burrs and the like.

The blunt edge refers to the straight edge part of the end face along the root part of the welding part joint bevel when the welding part is beveled.

The bevel angle refers to the included angle between the two bevel surfaces.

The bevel face angle refers to an included angle between the end face of the groove to be machined and the bevel face.

The lower groove is adjacent to the truncated edge, and the lower groove is adjacent to the upper groove.

The bottom of the small end of the double V-shaped composite groove refers to the end close to the blunt edge.

The distance between the turning point of the groove and the bottom edge of the tank wall plate refers to the side of the tank wall plate vertically connected with the blunt edge.

According to the welding method of the tank wall plate of the soil covering tank, the tank wall plate is transversely welded and vertically welded in a mixed gas shielded welding mode, the welding mode is combined with a specific double-V-shaped composite groove (the groove angle of a lower groove is 42.5-47.5 degrees, the groove surface angle of an upper groove is 3.5-6.5 degrees, the length of a truncated edge is 0.5-1.5 mm, the distance between the inflection point of the groove and the bottom edge of the tank wall plate is 4-6 mm) and specific mixed gas, the filling amount of a welding seam can be reduced on the premise of ensuring the quality of the welding seam, the welding efficiency is improved, the comprehensive welding work efficiency is improved by 30%, and the welding construction cost is reduced.

In the welding method of the tank wall plate of the soil covering tank, the groove angle of the groove at the lower section is set to be 42.5-47.5 degrees, so that the mixed gas shielded welding is facilitated to ensure that a contact tip of a welding gun can extend to the bottom of the groove when horizontal welding and vertical up-welding are carried out, the dry extension of a welding wire can be shorter, and the welding wire can be well protected by the shielding gas during welding; and the groove can swing when the lower-section groove is welded, the edge of the groove is fully melted, the incomplete fusion is avoided, the quality of a welding seam is ensured, the angle of the bevel face of the upper-section groove is set to be 3.5-6.5 degrees, the size of the groove is reduced, the filling amount is reduced, and the welding cost is reduced. In addition, when the tank wall plate is transversely welded and vertically welded, the adopted gas is mixed gas consisting of 75 vol% -85 vol% of carbon dioxide and 15 vol% -25 vol% of argon, the 75 vol% -85 vol% of carbon dioxide is favorable for obtaining larger fusion depth, the full penetration during bottoming is ensured, and the 15 vol% -25 vol% of argon is favorable for reducing welding spatter.

The method comprises the steps of firstly processing a double-V-shaped composite groove on a tank wall plate, and then performing transverse welding and vertical welding on the tank wall plate by adopting mixed gas shielded welding. The double-V-shaped composite groove is a narrow-gap double-V-shaped composite groove, the filling material in a welding seam is less, the cost is reduced, the welding time is shortened, the groove of the double-V-shaped composite groove has good weldability, the welding quality is ensured, and in addition, the groove shape of the double-V-shaped composite groove is easy to process; the adopted mixed gas shielded welding can effectively improve the welding efficiency, has small splashing and small labor intensity of an electric welder. The method greatly improves the welding efficiency, reduces the welding cost, improves the working environment, is suitable for the construction of the tank wall plate of the soil covering tank, and solves the welding problem of the soil covering tank.

The method is used for performing horizontal welding and vertical welding on the tank wall plate, and the mixed gas shielded welding equipment for the horizontal welding and the vertical welding is simple and low in cost.

In order to further ensure the welding quality and reduce the consumption of welding materials and the cost, preferably, in the step (1), the angle of the groove of the lower groove is 45 degrees, the angle of the bevel face of the upper groove is 5 degrees, the length of the truncated edge is 1mm, and the distance from the inflection point of the groove to the bottom edge of the tank wall plate is 5 mm.

Preferably, in the step (1), the assembling process parameters of the double V-shaped composite groove are as follows: the gap of the root of the groove is 2-2.5 mm, and the misalignment is less than 1.5 mm. The gap between the root parts of the grooves is 2-2.5 mm, so that the root penetration is guaranteed. The misalignment is less than 1.5mm, which is beneficial to the assembly of the double V-shaped composite groove.

In order to ensure the machining precision, in step (1), the machining method for machining the double-V composite groove is preferably mechanical cold machining.

Preferably, in the step (1), the thickness of the tank wall plate is 12-30 mm. The welding method of the tank wall plate of the soil covering tank is suitable for tank wall plates with the thickness of 12-30 mm.

Preferably, in the step (2), during welding, the priming layer, the filling layer and the cover surface layer are welded in sequence from the bottom of the small end of the double-V-shaped composite groove; the welding current that welding priming layer adopted is 90 ~ 130A, the welding current that welding filling layer adopted is 180 ~ 200A, the welding current that welding capping layer adopted is 180 ~ 200A. Under the condition of the welding current, the mode of welding the priming layer, the filling layer and the cover surface layer in sequence is favorable for obtaining well-formed transverse welding seams and vertical welding seams.

Preferably, the inter-track temperature of the weld is 150 ℃ or less.

In order to ensure root penetration, avoid back carbon arc gouging back chipping, improve welding efficiency, improve operating environment and shorten construction time, preferably, the forming technology adopted by the welding backing layer is a single-side welding double-side forming technology.

In order to further ensure that the priming layer, the filling layer and the cover surface layer are well formed, preferably, the welding priming layer adopts the following process parameters: the welding current is 90-130A, the voltage is 18-20V, the diameter of a welding wire is 1.2mm, the welding speed is 16-22 cm/min, the wire feeding speed is 80-110 in/min, the elongation of the welding wire is 8-12 mm, and the gas flow is 20-30L/min; the welding filling layer adopts the following technological parameters: the welding current is 180-200A, the voltage is 23-26V, the diameter of a welding wire is 1.2mm, the welding speed is 18-22 cm/min, the wire feeding speed is 90-110 in/min, the elongation of the welding wire is 8-12 mm, and the gas flow is 20-30L/min; the welding cover surface layer adopts the following technological parameters: the welding current is 180-200A, the voltage is 23-26V, the diameter of a welding wire is 1.2mm, the welding speed is 14-20 cm/min, the wire feeding speed is 80-100 in/min, the elongation of the welding wire is 8-12 mm, and the gas flow is 20-30L/min.

In order to further reduce spatter while ensuring penetration, it is preferable that the shielding gas used in the mixed gas shielded welding in step (2) is a mixed gas of 80 vol% of carbon dioxide and 20 vol% of argon gas.

Drawings

Fig. 1 is a schematic view of a double V-shaped compound groove of example 1.

Detailed Description

The present invention will be further described with reference to the following embodiments.

In the welding method of the wall plate of the earth covering tank of the embodiment of the invention, the wall plate can adopt steel plates made of materials such as Q245R, Q345R and the like. The thickness of the tank wall plate is 12-30 cm.

In the welding method of the wall plate of the soil covering tank, the welding wire for mixed gas shielded welding adopts a solid welding wire.

In the welding method of the tank wall plate of the soil covering tank provided by the embodiment of the invention, the tank wall plate is assembled by adopting a flip-chip method.

The raw materials such as the plate material, the welding material and the like used in the embodiment of the invention must have the ex-factory qualification certificate and the material quality certificate. The appearance of the steel plate has no defects of cracks, slag inclusion, pockmarks, mechanical damage and the like.

The concrete embodiment of the welding method of the tank wall plate of the soil covering tank of the invention is as follows: