CN112620898B

CN112620898B - Welding process method for Q500qENH weather-resistant steel angle joint in alpine region

Info

Publication number: CN112620898B
Application number: CN202011595893.0A
Authority: CN
Inventors: 李方敏; 郭红艳; 陈潜; 徐慰玉; 黄勇; 朱东明; 王员根; 高波; 付建辉; 潘云龙; 黄旭光; 王磊; 李正兵; 刘翔; 肖辉东; 王中美
Original assignee: China Railway Hi Tech Industry Corp Ltd; China Railway Jiujiang Bridge Engineering Co Ltd
Current assignee: China Railway Hi Tech Industry Corp Ltd; China Railway Jiujiang Bridge Engineering Co Ltd
Priority date: 2020-12-28
Filing date: 2020-12-28
Publication date: 2022-05-17
Anticipated expiration: 2040-12-28
Also published as: CN112620898A

Abstract

The invention discloses a welding process method for a Q500qENH weather-resistant steel corner joint in a alpine region, which can overcome the adverse effect of the alpine environment of the plateau on the welding performance, and improve the low-temperature toughness, the crack resistance and the weather resistance of the welding joint, thereby obtaining the welding joint with good mechanical properties and weather resistance, realizing the matched welding of large-span, heavy-load, high-strength, high-toughness and high-weather-resistant bridge steel in the alpine region of the plateau, simultaneously avoiding the preheating before welding and the heat treatment after welding, improving the production efficiency and reducing the energy consumption.

Description

Welding process method for Q500qENH weather-resistant steel angle joint in alpine region

Technical Field

The invention relates to a process method for manufacturing and welding a heavy-duty bridge, in particular to a process method for welding a Q500qENH weather-resistant steel angle joint in a high and cold area.

Background

According to research, weathering steel bridges are widely used in the United states and Japan, more than 23000 U.S. weathering steel bridges are accumulated in 1993, and coating-free weathering steel is adopted in 7% of U.S. weathering steel bridges and 45% of U.S. steel bridges in Japan and Japan in 2000. The development of the weather-resistant steel bridge in China is in the initial stage, the related technology generally refers to the American standard, and meanwhile, the control problems of the durability of the coating-free weather-resistant steel bridge and the like are solved.

The national key engineering Sichuan-Tibet railway is designed to be at the middle section (Yaan to Linzhi) of China, with the double line level 1, the motor train unit speed per hour of 120-200 km, the length of the front line of 1011 kilometers, and spanning river areas such as big river, Yazheng river, Jinsha river, billu river, Nuangjiang river and the like, and the control engineering comprises a plurality of super-large-span steel bridges. The engineering design and construction difficulty is great when the bridge faces severe geographical conditions such as high plateau ultraviolet rays, high cold and oxygen deficit, permafrost, collapse, dislocation, landslide, earthquake, terrestrial heat, rockburst and the like, but the air quality is excellent, the humidity is overall moderate (local high humidity in summer in the forest ganoderma area), the bridge belongs to the typical rural atmospheric environment, and the bridge is suitable for constructing a coating-free weather-resistant steel bridge.

At present, Q500qENH weather-resistant bridge steel is a main steel material of a coating-free weather-resistant steel bridge, and a welding joint of the steel is required to have excellent low-temperature toughness, crack resistance and weather resistance in construction, and the method specifically comprises the following steps: the yield strength is more than or equal to 500 Mpa; the tensile strength is more than or equal to 630 Mpa; the elongation is more than or equal to 18 percent; the low-temperature impact energy of-40 ℃ KV2 is more than or equal to 54J.

However, the technical problems to be solved at present are that the Q500qENH weather-resistant bridge steel is increased along with the alloy content, the carbon equivalent is correspondingly improved, and the welding performance is poor; meanwhile, the requirements of the preheating process before welding and the heat treatment process after welding in the alpine environment of the plateau are more strict; the conventional welding process method and measures are difficult to meet the standards.

The invention discloses a welding process method for a Q500qENH weather-resistant steel angle joint in a high and cold area, which can overcome the adverse effect of the high and cold environment of the plateau on the welding performance, and can improve the low-temperature toughness, the crack resistance and the weather resistance of the welding joint, thereby obtaining the welding joint with good mechanical properties and weather resistance, realizing the matched welding of large-span, heavy-load, high-strength, high-toughness and high-weather-resistant bridge steel in the high and cold area of the plateau, simultaneously avoiding the preheating before welding and the heat treatment after welding, improving the production efficiency and reducing the energy consumption.

Disclosure of Invention

The invention develops a welding process method for a Q500qENH weather-resistant steel angle joint in a severe cold region, the low-temperature toughness, the crack resistance and the weather resistance of the welded joint obtained by the process method are extremely excellent, and meanwhile, pre-welding preheating and post-welding heat treatment are not needed, so that the production efficiency is improved, and the energy consumption is reduced.

The invention discloses a process method for welding a Q500qENH weathering resistant steel angle joint in a severe cold area, which comprises the following steps:

(I) pretreatment of the weld face

(1) Polishing the welding surface and the adjacent area to remove impurities such as rust on the surface;

(II) cutting treatment of welding surface

(2) The welding seam adopts a double-sided asymmetric groove mode, the length of the truncated edge is 2mm, the center of the truncated edge is positioned at the position close to the center of the welded plate, and the ratio of the distance from the center of the truncated edge to the edge of the far-end welded plate to the thickness of the whole plate is 0.55-0.65; the bevel angle is 45-50 degrees;

(3) polishing again to remove metal scraps, and butting the truncated edges of the welded plates with the substrate;

welding forming process for (triangular) angle joint

(4) Welding: welding the groove by adopting a welding wire with the tensile strength of deposited metal being more than or equal to 650 MPa;

(5) the temperature between the roads in the step (4) is controlled to be 80-180 ℃;

(6) and after the groove on one side is welded by the process, the groove on the other side is continuously welded.

Further, the welding wire used in the step (4) is CHT91NHQ or the welding wire with patent number 202010907383.6 and the name of C02 gas shielded welding wire and wire rod with the tensile strength of 650MPa for coating-free weathering steel bridge, or the welding wire with patent number 202010907903.3 and the name of argon-rich gas shielded welding wire and wire rod with the tensile strength of 650MPa for coating-free weathering steel bridge, and shielding gas CO₂Ar is 20-100: 0-80 by volume; the technological parameters of the gas shielded welding are that the current is kept between 180A and 280A, the voltage is kept between 25V and 30V, the welding speed is kept between 24cm/min and 30cm/min, the flow of the shielding gas is kept between 15L/min and 25L/min, and the linear energy is kept between 10KJ/cm and 14 KJ/cm.

Or, the welding in the step (4) adopts a mode of gas shielded welding bottoming and submerged arc automatic welding filling, the welding wire for gas shielded welding is the welding wire with the patent number of 202010907383.6 and the name of C02 gas shielded welding wire and wire rod with the tensile strength of 650MPa for the coating-free weather-resistant steel bridge, and the shielding gas is CO₂The technological parameters of the gas shielded welding are that the current is kept between 180A and 280A, the voltage is kept between 25V and 30V, the welding speed is kept between 30cm/min and 35cm/min, the flow of the shielding gas is kept between 15L/min and 25L/min, and the linear energy is kept between 14KJ/cm and 16 KJ/cm; the submerged arc automatic welding wire is a welding wire with the patent number of 202010907395.9 and the invention name of 650 MPa-level tensile strength submerged arc automatic welding wire and wire rod for a coating-free weather-resistant steel bridge, and the matched welding flux is SJ105 Nq; the technological parameters of the automatic submerged arc welding are that the current is kept between 650A and 700A, the voltage is kept between 30V and 35V, the welding speed is kept between 35cm/min and 40cm/min, and the linear energy is kept between 30KJ/cm and 32 KJ/cm.

Further, the ratio of the center of the blunt edge to the edge of the distal welded blank to the thickness of the entire blank is preferably 0.618 golden section point.

The invention relates to a process method for welding Q500qENH weathering resistant steel angle joints in alpine regions, which comprises the following steps:

(I) pretreatment of the weld face

(II) cutting treatment of welding surface

(2) The welding seam adopts a single-sided groove mode, and the proportion of the length of the truncated edge to the thickness of the whole plate is 0.5-0.65; the bevel angle is 45-50 degrees;

welding forming process for (triangular) angle joint

(4) And (3) welding and bottoming: the priming adopts a welding wire with the tensile strength of deposited metal being more than or equal to 650MPa, and gas shielded welding is adopted for priming;

(5) welding and filling: welding and filling the residual area, and filling by adopting a welding wire and a matched welding flux with the tensile strength of deposited metal being more than or equal to 650MPa by a submerged arc automatic welding method;

(6) and (3) controlling the inter-channel temperature of the priming layer in the step (4) and the welding filling layer in the step (5) to be 80-180 ℃.

Further, in the gas shielded welding used in the welding backing in the step (4), the welding wire is JQ.TH 650 EW-II or 202010907383.6 named as C02 grade gas shielded welding wire and wire rod with the tensile strength of 650MPa for coating-free weather-resistant steel bridge, and the shielding gas is CO₂(ii) a The technological parameters of the gas shielded welding are that the current is kept between 180A and 280A, the voltage is kept between 25V and 30V, the welding speed is kept between 30cm/min and 35cm/min, the flow of the shielding gas is kept between 15L/min and 25L/min, and the linear energy is kept between 14KJ/cm and 16 KJ/cm.

Furthermore, the welding wire used in the welding filler in the step (5) is SD-H08Mn2E or 202010907395.9 named as 650 MPa-level tensile strength submerged arc automatic welding wire and wire rod for coating-free weather-resistant steel bridges, and the matched flux is SJ105 Nq; the technological parameters of the automatic submerged arc welding are that the current is kept between 650A and 700A, the voltage is kept between 30V and 35V, the welding speed is kept between 35cm/min and 40cm/min, and the linear energy is kept between 30KJ/cm and 32 KJ/cm.

Further, the ratio of the length of the truncated edge to the thickness of the overall sheet is preferably 0.618 golden section point.

Furthermore, in the 2 processes, before the welding forming process of the third step (third step) of the corner joint is used for welding, a liner is added at the bottom of the groove, and the liner can adapt to the shape of the groove.

Further, the pad comprises a first load bearing area 1, a second load bearing area 2 and a heat dissipation area 3, wherein the heat dissipation area 3 is composed of 3 layers: the uppermost layer is a microporous breathable layer 31, the middle layer is a bearing sealing layer 32, and the lowermost layer is a bottom sealing layer 33; the microporous gas-permeable layer 31 and the carrier-sealing layer 32 form CO₂A generation chamber 4 for the CO₂The generation chamber 4 is filled with CO which can be decomposed by heat to release CO₂Of the substance of (1), said CO₂A sealing plate 41 which can be opened and closed and sealed is arranged on the side of the generating cavity 4; the bearing sealing layer 32 and the bottom sealing layer 33 form a bottom heat absorption cavity 5, and the bottom heat absorption cavity 5 is filled with reversible heat absorption substances.

Further, the thermal decomposable release CO₂The substance of (a) is sodium bicarbonate.

Further, the reversible heat-absorbing substance is sodium sulfate decahydrate.

Further, the material of the liner is ceramic or steel.

The invention has the advantages that:

1. the Q500qENH high-performance weather-resistant bridge steel is not preheated before welding and does not undergo a heat treatment process after welding, and a welding joint of the high-performance weather-resistant bridge steel has excellent low-temperature toughness, crack resistance and weather resistance, and specifically comprises the following steps: the yield strength is more than or equal to 550Mpa, the tensile strength is more than or equal to 650Mpa, the elongation is more than or equal to 20 percent, the low-temperature impact energy of 40 ℃ KV2 is more than or equal to 80J, the yield strength is more than or equal to 500Mpa, the tensile strength is more than or equal to 630Mpa, the elongation is more than or equal to 18 percent, and the low-temperature impact energy of 40 ℃ KV2 is more than or equal to 54J. The invention has the advantages that a large number of tests are carried out, flaw detection is carried out, the phenomenon of crack generation is not found, the joint has higher impact toughness storage and safety margin, and the key technical requirements of manufacturing a large-span bridge steel structure in a severe cold area can be completely met.

2. The invention discloses a welding forming process method for a Q500qENH weather-resistant steel angle joint in a high and cold area, which fills the blank of the welding process manufacturing technology in the high and cold area planned in China.

3. The welding process disclosed by the invention has excellent welding process performance, is simple and convenient to operate, is suitable for being used conveniently, is efficient and energy-saving, can adapt to the climatic characteristics of Sichuan-Tibet areas, and particularly has obvious effects of improving the low-temperature toughness, the crack resistance and the weather resistance of a welding joint when the ambient temperature is 0-5 ℃ and the relative humidity is less than 80%. The method is suitable for manufacturing, popularizing and applying the high-performance weather-resistant bridge steel of the large-span bridge in the alpine region, and meets the technical requirements of matching welding of a new generation of high-strength, high-toughness and high-weather-resistant bridge steel in China.

4. Compared with the common welding process of pre-heating before welding and heat treatment after welding, the welding process is suitable for welding the Q500qENH weather-resistant bridge steel in the plateau high-cold environment, overcomes the adverse effect of the plateau high-cold environment on the welding performance, improves the low-temperature toughness, the crack resistance and the weather resistance of a welding joint, improves the production efficiency and reduces the energy consumption.

5. The key control point of the invention is that the temperature between the roads is controlled to be 80-180 ℃, wherein the gasket has the functions of bearing and heat conduction, and the CO arranged on the gasket₂The generation chamber can release CO from the bottom layer of the welded joint₂The protective gas improves the welding quality of gas shielded welding; the bottom heat absorption cavity arranged on the liner can further absorb welding heat, reduce inter-channel temperature, simultaneously has the function of relieving too fast temperature drop speed of a welding joint, is beneficial to generation of a bainite structure and an acicular ferrite structure, improves the control of the inter-channel temperature by the process disclosed by the invention, and greatly improves the quality of the whole welding process.

6. The invention utilizes the liner to fix the groove and relieve the welding stress, and simultaneously utilizes the liner which can be decomposed by heat to release CO₂The substances absorb the strong heat of welding and decompose CO₂So as to realize the omnibearing protection of welding and realize the function of rapid temperature reduction between the tracks; meanwhile, welding waste heat is absorbed by a reversible heat absorbing substance, so that the temperature between the roads cannot continuously and rapidly decrease when reaching 80-180 ℃, the temperature between the roads is more stably controlled, and the working time window is effectively increased; the invention can prevent the welding line from overheating and blackening, is beneficial to the generation of acicular ferrite tissues of the welding line, enhances various performances of a welding joint, and is particularly suitable for welding weather-resistant bridge steel in alpine regions.

7. The welding seam of the invention adopts a design mode of double-sided asymmetric grooves, the distance from the center of the truncated edge to the edge of the far-end welding plate accounts for the thickness of the whole plate, and the proportion of the length of the truncated edge to the thickness of the whole plate is designed near a golden section point, so that the stress generated by a steel plate can be relieved during welding, and the low-temperature toughness, the crack resistance and the weather resistance of a welding joint are improved.

Drawings

FIG. 1 is a diagram showing the welding effect of example 6 of the present invention at 0 ℃;

FIG. 2 is a diagram showing the welding effect of example 10 of the present invention at 0 ℃;

FIG. 3 is a schematic groove of example 6 of the present invention;

FIG. 4 is a schematic groove of example 10 of the present invention;

FIG. 5 is a cross-sectional view of a gasket of example 6 of the present invention (the gasket is wedged on one side of a double-sided asymmetric groove);

FIG. 6 is a front view of a sealing plate according to embodiment 6 of the present invention;

FIG. 7 is a cross-sectional view of a gasket according to example 10 of the present invention (the gasket is placed under a welded plate);

FIG. 8 is a front view of a sealing plate according to embodiment 10 of the present invention;

in the figure, the truncated edge is the bottom corner joint in the bevel schematic diagram of fig. 3 and the vertical part in the bevel schematic diagram of fig. 4; the length of the blunt edge is marked as "H"; the bevel angle is marked as "α";

in the figure, 1-the first load-bearing zone, 2-the second load-bearing zone, 3-the heat-dissipating zone, 31-the microporous breathable layer, 32-the load-bearing sealing layer, 33-the bottom sealing layer, 4-CO₂Take place ofChamber, 41-sealing plate, 5-bottom heat absorption chamber

Detailed Description

Example 1

A process method for welding Q500qENH weathering resistant steel angle joints in alpine regions comprises the following steps:

(I) pretreatment of the weld face

(II) cutting treatment of welding surface

(2) The welding seam adopts a double-sided asymmetric groove mode, the length of the truncated edge is 2mm, the center of the truncated edge is positioned at the position close to the center of the welded plate, and the ratio of the distance from the center of the truncated edge to the edge of the welded plate at the far end to the thickness of the whole plate is 0.55; the bevel angle is 45 degrees;

welding forming process for (triangular) angle joint

(5) controlling the temperature between the roads in the step (4) to be 180 ℃;

And (4) performing gas shielded welding in the step (4), wherein the welding wire is CHT91NHQ, and the shielding gas is CO₂The volume ratio of Ar is 100: 0. The technological parameters of the gas shielded welding are that the current is kept at 180A, the voltage is 25V, the welding speed is 24cm/min, the flow of the shielding gas is 15L/min, and the linear energy is 10 KJ/cm.

In the process, before the third step of the angle joint welding forming process is used for welding, the gasket is added at the bottom of the groove, and the gasket can adapt to the shape of the groove.

The pad comprises a first load bearing area 1, a second load bearing area 2 and a heat dissipation area 3, wherein the heat dissipation area 3 consists of 3 layers: the uppermost layer is a microporous breathable layer 31, the middle layer is a bearing sealing layer 32, and the lowermost layer is a bottom sealing layer 33; the microporous breathable layer 31 and the load-bearing sealing layer32 formation of CO₂A generation chamber 4 for the CO₂The generation chamber 4 is filled with CO which can be decomposed by heat and released₂Of the substance of (1), said CO₂ A sealing plate 41 which can be opened and closed and sealed is arranged on the side of the generating cavity 4; the bearing sealing layer 32 and the bottom sealing layer 33 form a bottom heat absorption cavity 5, and the bottom heat absorption cavity 5 is filled with reversible heat absorption substances.

The thermally decomposable release of CO₂The substance of (a) is sodium bicarbonate.

The reversible heat-absorbing substance is sodium sulfate decahydrate.

The material of the liner is ceramic.

Example 2

(I) pretreatment of the weld face

(II) cutting treatment of welding surface

(2) The welding seam adopts a double-sided asymmetric groove mode, the length of the truncated edge is 2mm, the center of the truncated edge is positioned at the position close to the center of the welded plate, and the ratio of the distance from the center of the truncated edge to the edge of the welded plate at the far end to the thickness of the whole plate is 0.618; the bevel angle is 50 degrees;

welding forming process for (triangular) angle joint

(5) controlling the temperature between the roads in the step (4) to be 130 ℃;

The welding wire of the gas shielded welding used in the step (4) is the welding wire with the patent number of 202010907383.6 and the invention name of C02 gas shielded welding wire and wire rod with the tensile strength of 650MPa for the coating-free weather-resistant steel bridge, and the shielding gas is CO₂Ar volumeThe ratio was 60: 40. The technological parameters of the gas shielded welding are that the current is kept to be 250A, the voltage is 28V, the welding speed is 24cm/min, the flow of the shielding gas is 20L/min, and the linear energy is 14 KJ/cm.

The pad comprises a first load bearing area 1, a second load bearing area 2 and a heat dissipation area 3, wherein the heat dissipation area 3 consists of 3 layers: the uppermost layer is a microporous breathable layer 31, the middle layer is a bearing sealing layer 32, and the lowermost layer is a bottom sealing layer 33; the microporous gas-permeable layer 31 and the load-bearing sealing layer 32 form CO₂A generation chamber 4 for the CO₂The generation chamber 4 is filled with CO which can be decomposed by heat and released₂Of the substance of (1), said CO₂ A sealing plate 41 which can be opened and closed and sealed is arranged on the side of the generating cavity 4; the bearing sealing layer 32 and the bottom sealing layer 33 form a bottom heat absorption cavity 5, and the bottom heat absorption cavity 5 is filled with reversible heat absorption substances.

The reversible heat-absorbing substance is sodium sulfate decahydrate.

The material of the liner is ceramic.

Example 3

(I) pretreatment of the weld face

(II) cutting treatment of welding surface

(2) The welding seam adopts a double-sided asymmetric groove mode, the length of the truncated edge is 2mm, the center of the truncated edge is positioned at the position close to the center of the welded plate, and the proportion of the distance from the center of the truncated edge to the edge of the far-end welded plate to the thickness of the whole plate is 0.65; the bevel angle is 50 degrees;

welding forming process for (triangular) angle joint

(5) controlling the temperature between the roads in the step (4) to be 80 ℃;

(6) and after the groove on one side is welded by the process, continuously welding the groove on the other side.

The welding wire used in the step (4) is the welding wire with the patent number of 202010907903.3 and the invention name of argon-rich gas shielded welding wire and wire rod with the tensile strength of 650MPa for the coating-free weather-resistant steel bridge, and the shielding gas is CO₂The volume ratio of Ar is 20: 80. The technological parameters of the gas shielded welding are that the current is kept at 280A, the voltage is 30V, the welding speed is 30cm/min, the flow of the shielding gas is 25L/min, and the linear energy is 14 KJ/cm.

The reversible heat-absorbing substance is sodium sulfate decahydrate.

The gasket is made of steel.

Example 4

(I) pretreatment of the weld face

(II) cutting treatment of welding surface

(2) The welding seam adopts a mode of double-sided symmetrical grooves, the length of the truncated edge is 2mm, the center of the truncated edge is positioned at the position close to the center of the welding plate, and the ratio of the distance from the center of the truncated edge to the edge of the welding plate at the far end to the thickness of the whole plate is 0.50; the bevel angle is 40 degrees;

welding forming process for (triangular) angle joint

(5) controlling the temperature between the roads in the step (4) to be 70 ℃;

The welding wire used in the step (4) is the welding wire with the patent number of 202010907903.3 and the invention name of argon-rich gas shielded welding wire and wire rod with the tensile strength of 650MPa for the coating-free weather-resistant steel bridge, and the shielding gas is CO₂Ar is 10:90 in volume ratio. The technological parameters of the gas shielded welding are that the current is kept at 300A, the voltage is 35V, the welding speed is 35cm/min, the flow of the shielding gas is 14L/min, and the linear energy is 16 KJ/cm.

The pad comprises a first load bearing area 1, a second load bearing area 2 and a heat dissipation area 3, wherein the heat dissipation area 3 consists of 3 layers: the uppermost layer is a microporous breathable layer 31, the middle layer is a bearing sealing layer 32, and the lowermost layer is a bottom sealing layer 33; the microporous gas-permeable layer 31 and the load-bearing sealing layer 32 form CO₂A generation chamber 4 for the CO₂The generation chamber 4 is filled with CO which can be decomposed by heat and released₂Of the substance of (1), said CO₂ A sealing plate 41 which can be opened and closed and sealed is arranged on the side of the generating cavity 4; the bearing sealThe layer 32 and said bottom sealing layer 33 form a bottom heat absorbing chamber 5, said bottom heat absorbing chamber 5 being filled with a reversible heat absorbing substance.

The reversible heat-absorbing substance is sodium sulfate decahydrate.

The gasket is made of steel.

Example 5

(I) pretreatment of the weld face

(II) cutting treatment of welding surface

welding forming process for (triangular) angle joint

The welding in the step (4) adopts a gas shielded welding bottoming and submerged arc automatic welding filling mode, the gas shielded welding wire is the welding wire with the patent number of 202010907383.6 and the invention name of C02 gas shielded welding wire and wire rod with the tensile strength of 650MPa for the coating-free weather-resistant steel bridge, and the shielding gas is CO₂The technological parameters of the gas shielded welding are that the current is kept at 180A, the voltage is 25V, the welding speed is 30cm/min, the flow of the shielding gas is 15L/min, and the linear energy is 14 KJ/cm; the submerged arc is automaticThe welding wire is the welding wire with the patent number of 202010907395.9 and the invention name of 'coating-free weather-resistant steel bridge submerged arc automatic welding wire and wire rod with the tensile strength of 650MPa grade', and the matched welding flux is SJ105 Nq; the technological parameters of the automatic submerged arc welding are that the current is kept at 650A, the voltage is 30V, the welding speed is 35cm/min, and the linear energy is 30 KJ/cm.

The reversible heat-absorbing substance is sodium sulfate decahydrate.

The material of the liner is ceramic.

Example 6

(I) pretreatment of the weld face

(II) cutting treatment of welding surface

welding forming process for (triangular) angle joint

The welding in the step (4) adopts a gas shielded welding bottoming and submerged arc automatic welding filling mode, the gas shielded welding wire is the welding wire with the patent number of 202010907383.6 and the invention name of C02 gas shielded welding wire and wire rod with the tensile strength of 650MPa for the coating-free weather-resistant steel bridge, and the shielding gas is CO₂The technological parameters of the gas shielded welding are that the current is kept to be 250A, the voltage is 28V, the welding speed is 30cm/min, the flow of the shielding gas is 20L/min, and the linear energy is 14 KJ/cm; the submerged arc automatic welding wire is the welding wire with the patent number of 202010907395.9 and the invention name of 'the submerged arc automatic welding wire and the wire rod with the tensile strength of 650MPa for the coating-free weather-resistant steel bridge', and the matched welding flux is SJ105 Nq; the technological parameters of the automatic submerged arc welding are that the current is kept at 650A, the voltage is 31V, the welding speed is 40cm/min, and the linear energy is 30 KJ/cm.

The pad comprises a first load bearing area 1, a second load bearing area 2 and a heat dissipation area 3, wherein the heat dissipation area 3 consists of 3 layers: the uppermost layer is a microporous breathable layer 31, the middle layer is a bearing sealing layer 32, and the lowermost layer is a bottom sealing layer 33; the microporous gas-permeable layer 31 and the load-bearing sealing layer 32 form CO₂A generation chamber 4 for the CO₂The generation chamber 4 is filled with CO which can be decomposed by heat to release CO₂Of the substance of (1), said CO₂ A sealing plate 41 which can be opened and closed and sealed is arranged on the side of the generating cavity 4; the bearing sealing layer 32 and the bottom sealing layer 33 form a bottom heat absorption cavity 5, and the bottom heat absorption cavity 5 is filled with reversible heat absorption substances.

The reversible heat-absorbing substance is sodium sulfate decahydrate.

The material of the liner is ceramic.

Example 7

(I) pretreatment of the weld face

(II) cutting treatment of welding surface

welding forming process for (triangular) angle joint

(5) controlling the temperature between the roads in the step (4) to be 80 ℃;

The welding in the step (4) adopts a gas shielded welding bottoming and submerged arc automatic welding filling mode, the gas shielded welding wire is the welding wire with the patent number of 202010907383.6 and the invention name of C02 gas shielded welding wire and wire rod with the tensile strength of 650MPa for the coating-free weather-resistant steel bridge, and the shielding gas is CO₂The technological parameters of the gas shielded welding are that the current is kept at 280A, the voltage is 30V, the welding speed is 35cm/min, the flow of the shielding gas is 25L/min, and the linear energy is 16 KJ/cm; the submerged automatic arc welding wire is a submerged automatic arc welding wire with the patent number of 202010907395.9 and the invention name of 650 MPa-level tensile strength for coating-free weather-resistant steel bridgesThe welding wire of the wire and wire rod is matched with SJ105 Nq; the technological parameters of the automatic submerged arc welding are that the current is kept at 700A, the voltage is 35V, the welding speed is 40cm/min, and the linear energy is 32 KJ/cm.

The reversible heat-absorbing substance is sodium sulfate decahydrate.

The gasket is made of steel.

Example 8

(I) pretreatment of the weld face

(II) cutting treatment of welding surface

(2) The welding seam adopts a double-sided symmetrical groove mode, the length of the truncated edge is 2mm, the center of the truncated edge is positioned at the position close to the center of the welded plate, and the ratio of the distance from the center of the truncated edge to the edge of the welded plate at the far end to the thickness of the whole plate is 0.50; the bevel angle is 40 degrees;

welding forming process for (triangular) angle joint

(5) controlling the temperature between the roads in the step (4) to be 190 ℃;

The welding in the step (4) adopts a gas shielded welding bottoming and submerged arc automatic welding filling mode, the gas shielded welding wire is the welding wire with the patent number of 202010907383.6 and the invention name of C02 gas shielded welding wire and wire rod with the tensile strength of 650MPa for the coating-free weather-resistant steel bridge, and the shielding gas is CO₂The technological parameters of the gas shielded welding are that the current is kept at 170A, the voltage is 24V, the welding speed is 40cm/min, the flow of the shielding gas is 14L/min, and the linear energy is 12 KJ/cm; the submerged arc automatic welding wire is the welding wire with the patent number of 202010907395.9 and the invention name of 'the submerged arc automatic welding wire and the wire rod with the tensile strength of 650MPa for the coating-free weather-resistant steel bridge', and the matched welding flux is SJ105 Nq; the technological parameters of the automatic submerged arc welding are that the current is kept at 620A, the voltage is 28V, the welding speed is 45cm/min, and the linear energy is 28 KJ/cm.

The reversible heat-absorbing substance is sodium sulfate decahydrate.

The gasket is made of steel.

Example 9

(I) pretreatment of the weld face

(II) cutting treatment of welding surface

(2) The welding seam adopts a single-side groove mode, and the ratio of the length of the truncated edge to the thickness of the whole plate is 0.5; the bevel angle is 45 degrees;

(3) polishing again to remove metal scraps, and then butting the truncated edge of the welded plate and the substrate together;

welding forming process for (triangular) angle joint

(6) and (5) controlling the inter-channel temperature of the priming layer in the step (4) and the welding filling layer in the step (5) to be 180 ℃.

The gas shielded welding used for the welding backing in the step (4) is JQ.TH 650 EW-II, and the shielding gas is CO₂. The technological parameters of the gas shielded welding are that the current is kept at 180A, the voltage is 25V, the welding speed is 30cm/min, the flow of the shielding gas is 15L/min, and the linear energy is 14 KJ/cm.

And (3) welding wires used in the welding and filling in the step (5) are SD-H08Mn2E, and the matched flux is SJ105 Nq. The technological parameters of the automatic submerged arc welding are that the current is kept at 650A, the voltage is 30V, the welding speed is 35cm/min, and the linear energy is 30 KJ/cm.

Further, in the 2 processes, before the third corner joint welding forming process is used for welding, a liner is added to the bottom of the groove, and the liner can adapt to the shape of the groove.

Further, the pad comprises a first load bearing area 1, a second load bearing area 2 and a heat dissipation area 3, wherein the heat dissipation area 3 is composed of 3 layers: the uppermost layer is a microporous breathable layer 31, the middle layer is a bearing sealing layer 32, and the lowermost layer is a bottom sealing layer 33; the microporous gas-permeable layer 31 and the load-bearing sealing layer 32 form CO₂A generation chamber 4 for the CO₂The generation chamber 4 is filled with CO which can be decomposed by heat and released₂Of the substance of (1), said CO₂ A sealing plate 41 which can be opened and closed and sealed is arranged on the side of the generating cavity 4; the bearing sealing layer 32 and the bottom sealing layer 33 form a bottom heat absorption cavity 5, and the bottom heat absorption cavity 5 is filled with reversible heat absorption substances.

Further, the reversible heat-absorbing substance is sodium sulfate decahydrate.

Further, the material of the liner is ceramic.

Example 10

A process method for welding Q500qENH weathering resistant steel angle joint in alpine regions comprises the following steps:

(I) pretreatment of the weld face

(II) cutting treatment of welding surface

(2) The welding seam adopts a single-side groove mode, and the ratio of the length of the truncated edge to the thickness of the whole plate is 0.618; the bevel angle is 50 degrees;

welding forming process for (triangular) angle joint

(6) and (3) controlling the inter-channel temperature of the priming layer in the step (4) and the welding filling layer in the step (5) to be 130 ℃.

The welding wire used for the backing welding in the step (4) is the welding wire with the patent number of 202010907383.6 and the invention name of C02 gas shielded welding wire and wire rod with the tensile strength of 650MPa for the coating-free weather-resistant steel bridge, and the shielding gas is CO₂. The technological parameters of the gas shielded welding are that the current is kept to be 250A, the voltage is 28V, the welding speed is 30cm/min, the flow of the shielding gas is 20L/min, and the linear energy is 14 KJ/cm.

The welding wire used in the step (5) for filling welding is the welding wire with the patent number of 202010907395.9 and the invention name of 'coating-free weather-resistant steel bridge submerged arc automatic welding wire and wire rod with the tensile strength of 650MPa grade', and the matched welding flux is SJ105 Nq. The technological parameters of the automatic submerged arc welding are that the current is kept at 650A, the voltage is 31V, the welding speed is 40cm/min, and the linear energy is 30 KJ/cm.

Further, the pad comprises a first load-bearing area 1, a second load-bearing area 2 and a heat dissipation area 3, wherein the heat dissipation area 3 consists of 3 layers: the uppermost layer is a microporous breathable layer 31, the middle layer is a bearing sealing layer 32, and the lowermost layer is a bottom sealing layer 33; the microporous gas-permeable layer 31 and the load-bearing sealing layer 32 form CO₂A generation chamber 4 for the CO₂The generation chamber 4 is filled with CO which can be decomposed by heat and released₂Of the substance of (1), said CO₂ A sealing plate 41 which can be opened and closed and sealed is arranged on the side of the generating cavity 4; the bearing sealing layer 32 and the bottom sealing layer 33 form a bottom heat absorption cavity 5, and the bottom heat absorption cavity 5 is filled with reversible heat absorption substances.

Further, the reversible heat-absorbing substance is sodium sulfate decahydrate.

Further, the material of the liner is ceramic.

Example 11

(I) pretreatment of the weld face

(II) cutting treatment of welding surface

(2) The welding seam adopts a single-side groove mode, and the proportion of the length of the truncated edge to the thickness of the whole plate is 0.65; the bevel angle is 50 degrees;

welding forming process for (triangular) angle joint

(6) and (5) controlling the inter-channel temperature of the priming layer in the step (4) and the welding filling layer in the step (5) to be 80 ℃.

The welding wire used for the backing welding in the step (4) is the welding wire with the patent number of 202010907383.6 and the invention name of C02 gas shielded welding wire and wire rod with the tensile strength of 650MPa for the coating-free weather-resistant steel bridge, and the shielding gas is CO₂. The technological parameters of the gas shielded welding are that the current is kept at 280A, the voltage is 30V, the welding speed is 35cm/min, the flow of the shielding gas is 25L/min, and the linear energy is 16 KJ/cm.

The welding wire used in the step (5) for filling welding is the welding wire with the patent number of 202010907395.9 and the invention name of 'coating-free weather-resistant steel bridge submerged arc automatic welding wire and wire rod with the tensile strength of 650MPa grade', and the matched welding flux is SJ105 Nq. The technological parameters of the automatic submerged arc welding are that the current is kept at 700A, the voltage is 35V, the welding speed is 40cm/min, and the linear energy is 32 KJ/cm.

Further, the reversible heat-absorbing substance is sodium sulfate decahydrate.

Further, the material of the liner is steel.

Example 12

(I) pretreatment of the weld face

(II) cutting treatment of welding surface

(2) The welding seam adopts a single-side groove mode, and the ratio of the length of the truncated edge to the thickness of the whole plate is 0.45; the bevel angle is 40 degrees;

welding forming process for (triangular) angle joint

(6) and (3) controlling the inter-channel temperature of the priming layer in the step (4) and the welding filling layer in the step (5) to be 70 ℃.

The welding wire used for the backing welding in the step (4) is the welding wire with the patent number of 202010907383.6 and the invention name of C02 gas shielded welding wire and wire rod with the tensile strength of 650MPa for the coating-free weather-resistant steel bridge, and the shielding gas is CO₂. The technological parameters of the gas shielded welding are that the current is kept at 170A, the voltage is 24V, the welding speed is 40cm/min, the flow of the shielding gas is 14L/min, and the linear energy is 12 KJ/cm.

The welding wire used in the step (5) for filling welding is the welding wire with the patent number of 202010907395.9 and the invention name of 'coating-free weather-resistant steel bridge submerged arc automatic welding wire and wire rod with the tensile strength of 650MPa grade', and the matched welding flux is SJ105 Nq. The technological parameters of the automatic submerged arc welding are that the current is kept at 620A, the voltage is 28V, the welding speed is 45cm/min, and the linear energy is 28 KJ/cm.

Further, the pad comprises a first load bearing area 1, a second load bearing area 2 and a heat dissipation area 3, wherein the heat dissipation area 3 is composed of 3 layers: the uppermost layer is a microporous breathable layer 31, the middle layer is a bearing sealing layer 32, and the lowermost layer is a bottom sealing layer 33; the microporous gas-permeable layer 31 and the load-bearing sealing layer 32 form CO₂A generation chamber 4 for said CO₂The generation chamber 4 is filled with CO which can be decomposed by heat and released₂Of the substance of (1), said CO₂ A sealing plate 41 which can be opened and closed and sealed is arranged on the side of the generating cavity 4; the bearing sealing layer 32 and the bottom sealing layer 33 form a bottom heat absorption cavity 5, and the bottom heat absorption cavity 5 is filled with reversible heat absorption substances.

Further, the reversible heat-absorbing substance is sodium sulfate decahydrate.

Further, the material of the liner is steel.

Comparative example 1

A process method for welding Q500qENH weathering steel angle joints in alpine regions adopts a mode of double-sided symmetrical grooves, the length of a truncated edge is 2mm, the center of the truncated edge is positioned at the position close to the center of a welded plate, and the proportion of the distance from the center of the truncated edge to the edge of a far-end welded plate to the thickness of the whole plate is 0.50; the bevel angle is 40 degrees; the rest is the same as example 2.

Comparative example 2

A process method for welding Q500qENH weathering resistant steel angle joints in alpine regions is the same as that in the example 2 except that the temperature between the roads in the step (4) is controlled at 70 ℃.

Comparative example 3

A process method for welding Q500qENH weathering steel angle joint in alpine regions is characterized in that gas shielded welding is used in the step (4), welding wires are 202010907903.3 and named as argon-rich gas shielded welding wires and wire rods with the tensile strength of 650MPa for coating-free weathering steel bridges, and CO is shielding gas₂The volume ratio of Ar is 10: 90. The process parameters of the gas shielded welding were kept at 300A, 35V, 35cm/min welding speed, 14L/min shielding gas flow and 16KJ/cm linear energy, and the rest was the same as example 2.

Comparative example 4

A process method for welding Q500qENH weathering resistant steel angle joints in alpine regions is the same as that in example 2 except that no liner is added to the bottoms of grooves during welding.

Comparative example 5

A process method for welding Q500qENH weathering resistant steel angle joints in alpine regions is the same as that of embodiment 2, wherein a solid ceramic liner is added at the bottom of a groove during welding.

Comparative example 6

A welding process for the corner joint of Q500qENH weather-resistant steel in high-cold area features that only CO is used as the liner added to the bottom of bevel₂The ceramic lining of the chamber occurs, as in example 2.

Comparative example 7

A process method for welding Q500qENH weathering resistant steel angle joints in alpine regions is the same as the embodiment 2 except that a liner added at the bottom of a groove is a ceramic liner only with a bottom heat absorption cavity during welding.

Comparative example 8

A process method for welding Q500qENH weathering steel angle joints in alpine regions adopts a mode of double-sided symmetrical grooves, the length of a truncated edge is 2mm, the center of the truncated edge is positioned at the position close to the center of a welded plate, and the proportion of the distance from the center of the truncated edge to the edge of a far-end welded plate to the thickness of the whole plate is 0.50; the bevel angle is 40 degrees; the rest is the same as example 6.

Comparative example 9

A process method for welding Q500qENH weathering steel angle joints in alpine regions is characterized in that the temperature between the roads in the step (4) is controlled at 190 ℃; the rest is the same as example 6.

Comparative example 10

The welding process method of the Q500qENH weathering steel angle joint in the alpine region is characterized in that the welding in the step (4) adopts a gas shielded welding bottoming and submerged arc automatic welding filling mode, the welding wire for the gas shielded welding is the welding wire with the patent number of 202010907383.6 and the invention name of C02 gas shielded welding wire and wire rod with the tensile strength of 650MPa for the coating-free weathering steel bridge, and the protective gas is CO₂The technological parameters of the gas shielded welding are that the current is kept at 170A, the voltage is 24V, the welding speed is 40cm/min, the flow of the shielding gas is 14L/min, and the linear energy is 12 KJ/cm; the submerged arc automatic welding wire is the welding wire with the patent number of 202010907395.9 and the invention name of 'the submerged arc automatic welding wire and the wire rod with the tensile strength of 650MPa for the coating-free weather-resistant steel bridge', and the matched welding flux is SJ105 Nq; the technological parameters of the automatic submerged arc welding are that the current is kept at 620A, the voltage is 28V, the welding speed is 45cm/min, and the linear energy is 28 KJ/cm; the rest is the same as example 6.

Comparative example 11

The process method for welding the Q500qENH weathering resistant steel angle joint in the alpine region is the same as that in the example 6, and the welding flux matched in the step (4) is SJ 101.

Comparative example 12

A process method for welding Q500qENH weathering resistant steel angle joints in alpine regions is the same as that in example 6 except that no liner is added to the bottom of a groove during welding.

Comparative example 13

A process method for welding Q500qENH weathering resistant steel angle joints in alpine regions is the same as that in example 6, wherein a solid ceramic liner is added at the bottom of a groove during welding.

Comparative example 14

A welding process for the corner joint of Q500qENH weather-resistant steel in high-cold area features that only CO is used as the liner added to the bottom of bevel₂The ceramic lining of the chamber occurs, as in example 6.

Comparative example 15

A process method for welding Q500qENH weathering resistant steel angle joints in alpine regions is the same as that in example 6 except that a liner added at the bottom of a groove is a ceramic liner only with a bottom heat absorption cavity.

Comparative example 16

A process method for welding Q500qENH weathering resistant steel angle joints in alpine regions adopts a single-sided groove mode for welding seams, and the proportion of the length of a truncated edge to the thickness of an integral plate is 0.45; the bevel angle is 40 degrees; the rest is the same as in example 10.

Comparative example 17

In the cold-high area Q500qENH weathering steel angle joint welding process, the inter-channel temperature of the priming layer in the step (4) and the welding filling layer in the step (5) in the step (6) is controlled at 70 ℃; the rest is the same as in example 10.

Comparative example 18

A process method for welding Q500qENH weather-resistant steel angle joint in alpine regions is characterized in that gas shielded welding is used in the step (4), welding wires are 202010907383.6 and are named as C02 gas shielded welding wires and wire rods with the tensile strength of 650MPa for coating-free weather-resistant steel bridges, and protective gas is CO₂. The technological parameters of the gas shielded welding are that the current is kept at 170A, the voltage is 24V, the welding speed is 40cm/min, the flow of the shielding gas is 14L/min, and the linear energy is 12 KJ/cm; the rest is the same as in example 10.

Comparative example 19

A process method for welding a Q500qENH weathering steel angle joint in a severe cold region is characterized in that welding wires used for welding and filling in the step (5) are 202010907395.9 patent numbers and named as' coating-free weathering steel bridge submerged arc automatic welding wires and wire rods with 650 MPa-level tensile strength, and a matched welding flux is SJ105 Nq. The technological parameters of the automatic submerged arc welding are that the current is kept at 620A, the voltage is 28V, the welding speed is 45cm/min, and the linear energy is 28 KJ/cm; the rest is the same as in example 10.

Comparative example 20

A process for welding Q500qENH weathering steel angle joints in alpine regions is disclosed, wherein the flux matched in the step (5) is SJ101, and the rest is the same as in example 10.

Comparative example 21

A process method for welding Q500qENH weathering resistant steel angle joints in alpine regions, wherein no liner is added at the bottom of a groove during welding, and the rest is the same as in the embodiment 10.

Comparative example 22

A process method for welding Q500qENH weathering resistant steel angle joints in alpine regions, wherein a liner added at the bottom of a groove is a solid ceramic liner during welding, and the rest is the same as in the embodiment 10.

Comparative example 23

A welding process for the corner joint of Q500qENH weather-resistant steel in high-cold area features that only CO is used as the liner added to the bottom of bevel₂A ceramic lining of the chamber occurs, as in example 10.

Comparative example 24

A process method for welding Q500qENH weathering resistant steel angle joints in alpine regions, wherein a liner added at the bottom of a groove is a ceramic liner only with a bottom heat absorption cavity during welding, and the rest is the same as in example 10.

Detection and analysis:

the welding was carried out according to the procedure described in the examples and comparative examples, maintaining a relative humidity of 80% at 0 ℃ and 25 ℃ respectively. The thickness of the welded Q500qENH weather-resistant steel plate is 20mm +20mm, the Q500qENH weather-resistant steel plate with the specification is welded, and various physical and mechanical properties of a welded joint are tested: yield strength, tensile strength, elongation percentage, KV2 low-temperature impact energy at-40 ℃. The welding was repeated 5 times for each of the examples and comparative examples, and the physical mechanical properties were averaged.

Wherein, the test method of the yield strength, the tensile strength and the elongation rate is GB/T2652 and 2008 'weld joint and deposited metal tensile test method'; the testing method of the low-temperature impact energy of KV2 at the temperature of minus 40 ℃ is GB/T2650-2008 'welding joint impact test method'.

The specification of the groove, the control of the inter-road temperature, the selection of welding materials and welding flux and process parameters are preferably obtained after a large number of experiments, and the improved liner is matched, so that the Q500qENH high-performance weather-resistant bridge steel has excellent low-temperature toughness, crack resistance and weather resistance under the conditions of no preheating before welding and no heat treatment after welding, the welding joint has higher impact toughness reserve and safety margin, the key technical requirements of manufacturing a large-span bridge steel structure in a high-cold area can be completely met, the production efficiency is improved, and the energy consumption is reduced;

meanwhile, as can be seen from the above table, the welding process of the invention can weld the Q500qENH high-performance weather-resistant bridge steel when the ambient temperature is 0 ℃ and the relative humidity reaches 80%, and the low-temperature impact toughness still keeps higher safety margin under the conditions of no preheating before welding and no heat treatment after welding, can adapt to the climate characteristics of Sichuan-Tibet areas, and is simple and convenient to operate, convenient to apply, efficient and energy-saving; the invention can meet the technical requirements of the matching welding of a new generation of high-strength, high-toughness and high-weatherability bridge steel grade in China, and fills the blank of the welding process manufacturing technology in the severe cold areas proposed in China;

the key control point of the invention is that the temperature between the lanes is controlled to be 80 DEG CAbout 180 ℃ with a load-bearing and heat-conducting lining of CO₂The generation chamber can release CO from the bottom layer of the welded joint₂The protective gas is used as protective gas to realize the omnibearing protection of welding, so that the welding quality of gas shielded welding is improved; the bottom heat absorption cavity arranged on the liner can further absorb welding heat, reduce the inter-channel temperature, simultaneously has the function of relieving the too high temperature reduction speed of a welding joint, is beneficial to the generation of a bainite structure and an acicular ferrite structure, improves the control of the inter-channel temperature by the process disclosed by the invention, and greatly improves the quality of the whole welding process; meanwhile, the invention can prevent the welding line from being overheated and blackened, is beneficial to the generation of acicular ferrite tissues of the welding line, enhances various performances of a welding joint and is particularly suitable for welding weather-resistant bridge steel in alpine regions.

And finally: the above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that are within the spirit and principle of the present invention are intended to be included in the scope of the present invention.

Claims

1. A welding method for Q500qENH weather-resistant steel angle joints in alpine regions is characterized by comprising the following steps: the method comprises the following steps:

(I) pretreatment of the weld face

(1) Polishing the welding surface and the adjacent area to remove rust on the surface;

(II) cutting treatment of welding surface

(2) The welding seam adopts a double-sided asymmetric groove mode, the length of the truncated edge is 2mm, and the ratio of the distance from the center of the truncated edge to the edge of the far-end welding plate to the thickness of the whole plate is 0.55-0.65; the bevel angle is 45-50 degrees;

welding forming process for (triangular) angle joint

(4) Welding: welding the groove by adopting a welding wire with the tensile strength of the deposited metal being more than or equal to 650 MPa;

(6) after the groove on one side is welded by the process, the groove on the other side is continuously welded;

before the third step of welding and forming process of the angle joint is carried out, adding a liner at the bottom of the groove, wherein the liner can adapt to the shape of the groove;

the pad comprises a first load bearing area (1), a second load bearing area (2) and a heat dissipation area (3), wherein the heat dissipation area (3) consists of 3 layers: the uppermost layer is a microporous breathable layer (31), the middle layer is a bearing sealing layer (32), and the lowermost layer is a bottom sealing layer (33); the microporous gas-permeable layer (31) and the load-bearing sealing layer (32) form CO₂A generation chamber (4), said CO₂The generation cavity (4) is provided with a material which can be decomposed by heat to release CO₂Of the substance of (1), said CO₂A sealing plate (41) which can be opened and closed and sealed is arranged on the side of the generating cavity (4); the bearing sealing layer (32) and the bottom sealing layer (33) form a bottom heat absorption cavity (5), and reversible heat absorption substances are filled in the bottom heat absorption cavity (5); the thermally decomposable release of CO₂The substance of (a) is sodium bicarbonate; the reversible heat-absorbing substance is sodium sulfate decahydrate; the material of the liner is ceramic or steel.

2. The welding method of the Q500qENH weathering resistant steel angle joint in the alpine region as set forth in claim 1, characterized in that: the gas shielded welding used in the step (4) is performed by adopting a welding wire of CHT91NHQ and shielding gas CO₂Ar is 20-100: 0-80 by volume; the technological parameters of the gas shielded welding are that the current is kept between 180A and 280A, the voltage is kept between 25V and 30V, the welding speed is kept between 24cm/min and 30cm/min, the flow of the shielding gas is kept between 15L/min and 25L/min, and the linear energy is kept between 10KJ/cm and 14 KJ/cm.

3. The welding method of the Q500qENH weathering resistant steel angle joint in the alpine region as set forth in claim 1, characterized in that: the ratio of the center of the blunt edge to the edge of the distal welded blank to the thickness of the entire blank is 0.618 golden section point.

4. A welding method for Q500qENH weather-resistant steel angle joints in alpine regions is characterized by comprising the following steps: the method comprises the following steps:

(I) pretreatment of the weld face

(II) cutting treatment of welding surface

welding forming process for (triangular) angle joint

(6) controlling the inter-channel temperature of the priming layer in the step (4) and the welding filling layer in the step (5) to be 80-180 ℃;

the pad comprises a first load bearing area (1), a second load bearing area (2) and a heat dissipation area (3), wherein the heat dissipation area (3) consists of 3 layers: the uppermost layer is a microporous breathable layer (31), the middle layer is a bearing sealing layer (32), and the lowermost layer is a bottom sealing layer (33); the microporous gas-permeable layer (31) and the load-bearing sealing layer (32) form CO₂A generation chamber (4), said CO₂The generation cavity (4) is provided with a material which can be decomposed by heat to release CO₂Of the substance of (A), the CO₂A sealing plate (41) which can be opened and closed and sealed is arranged on the side of the generating cavity (4); the load-bearing seal (32) and the bottom seal (33)Forming a bottom heat absorption cavity (5), wherein the bottom heat absorption cavity (5) is filled with reversible heat absorption substances; the thermally decomposable release of CO₂The substance of (a) is sodium bicarbonate; the reversible heat-absorbing substance is sodium sulfate decahydrate; the material of the liner is ceramic or steel.

5. The welding method of the Q500qENH weathering steel angle joint in the alpine region as set forth in claim 4, characterized in that: the gas shielded welding used for the welding backing in the step (4) is JQ.TH 650 EW-II, and the shielding gas is CO₂(ii) a The technological parameters of the gas shielded welding are that the current is kept between 180A and 280A, the voltage is kept between 25V and 30V, the welding speed is kept between 30cm/min and 35cm/min, the flow of the shielding gas is kept between 15L/min and 25L/min, and the linear energy is kept between 14KJ/cm and 16 KJ/cm.

6. The welding method of the Q500qENH weathering steel angle joint in the alpine region as set forth in claim 4, characterized in that: the welding wire used in the welding and filling in the step (5) is SD-H08Mn2E, and the matched flux is SJ105 Nq; the technological parameters of the automatic submerged arc welding are that the current is kept between 650A and 700A, the voltage is kept between 30V and 35V, the welding speed is kept between 35cm/min and 40cm/min, and the linear energy is kept between 30KJ/cm and 32 KJ/cm.

7. The welding method of the Q500qENH weathering steel angle joint in the alpine region as set forth in claim 4, characterized in that: a golden section point having a ratio of the length of the truncated edge to the thickness of the overall sheet of 0.618.