CN113172313A

CN113172313A - Composite mixed submerged-arc welding flux and welding method thereof

Info

Publication number: CN113172313A
Application number: CN202110475718.6A
Authority: CN
Inventors: 张发荣; 刘伟新; 程登; 卢聪; 李正; 沈灿; 夏远焱
Original assignee: Hubei Jinggong Steel Structure Co ltd
Current assignee: Hubei Jinggong Steel Structure Co ltd
Priority date: 2021-04-29
Filing date: 2021-04-29
Publication date: 2021-07-27

Abstract

The invention discloses a composite mixed submerged-arc welding flux and a welding method thereof, the composite mixed submerged-arc welding flux comprises a sintered flux HJ431 and a smelted flux SJ101, the weight ratio of the sintered flux HJ431 to the smelted flux SJ101 is 5.5-8:1, the sintered flux HJ431 and the smelted flux SJ101 are mixed and combined, and a H10Mn2 welding wire is matched for use aiming at a specific welding object Q390BGJ-Z15 steel, so that the composite mixed submerged-arc welding flux is suitable for submerged-arc welding of a ship part, a cross part, a butt joint part and other joint parts of a factory component, and finally, the obtained welding line has good formability, slag removal performance and mechanical property, is attractive, the impact toughness of deposited metal is improved, and the welding process performance is improved; the energy consumption is less, the price of the welding flux is relatively lower, the production cost is effectively reduced, and harmful gas generated during welding is reduced.

Description

Composite mixed submerged-arc welding flux and welding method thereof

Technical Field

The invention belongs to the technical field of submerged-arc welding fluxes, and particularly relates to a composite mixed submerged-arc welding flux.

Background

Submerged arc welding was produced in 1935 and is suitable for straight-through welds of medium and thick plate structures due to its large penetration depth, high productivity and reliable mechanization. Therefore, submerged arc welding has wide application in the fields of shipbuilding industry, pressure vessel industry, bridges, railway vehicles, engineering machinery, pipelines, nuclear power plant structures, marine structures, building steel structures and the like, and is one of the most commonly used fusion welding methods in welding production at present.

At present, various double (multi) wire submerged arc welding methods exist in the submerged arc welding technology, but different types of steel need to be matched with different welding fluxes and welding wires, so that better welding quality can be obtained. Even if the same steel is adopted, the proportion of different welding fluxes and welding wires can affect the submerged-arc welding quality, the welding process control, the slag removal after welding and other related problems, and still is a permanent topic worth to be drawn and summarized.

Practice proves that on the aspect of welding material selection, quality differences (raw material grade, furnace burden formula, process quality control, magnetic separation, screening and the like) can be generated among different furnace numbers of different manufacturers of the same-grade welding flux. Aiming at submerged arc welding of a main steel Q390BGJ-Z15 steel plate in a factory at present, not only is the mechanical property of a welding seam met, but also cracks are avoided at the welding position, and the smooth operation of the actual production process of the welding seam is ensured. At present, H08MnA (welding wire) + HJ431 (flux) or H08MnA (welding wire) + SJ101 (flux) is mostly used as a welding flux for submerged arc welding, however, when Q390BGJ-Z15 steel is welded by the two conventional methods, the mechanical property requirements on design cannot be met, or the cost is too high;

in the prior art, for example, a reasonable mixing ratio of the slag removing performance when the common welding fluxes HJ431 and SJ101 are mixed and used is disclosed in a document of 'influence of mixed use of shallow precipitation welding fluxes HJ431 and SJ101 on the slag removing performance' (Han Eryang, construction technology, volume 45 at 2016, 12 months, 472-.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides a composite mixed submerged-arc welding flux, which is obtained by continuously searching and summarizing the submerged-arc welding process of a Q390BGJ-Z15 steel plate and applying a mode of matching and combining an H10Mn2 welding wire and fluxes of SJ101 and HJ431, not only effectively ensures the quality of a welding seam, but also controls the cost of welding materials, and is realized by the following technology.

A composite mixed submerged-arc welding flux comprises a sintered flux HJ431 and a smelted flux SJ101, and the weight ratio of the sintered flux HJ431 to the smelted flux SJ101 is 5.5-8: 1.

Preferably, the weight ratio of the sintered flux HJ431 to the smelted flux SJ101 is 7: 1.

Preferably, the sintered flux HJ431 is red brown glass-shaped particles with 8-40 meshes, and the water content is less than or equal to 0.10 percent; the smelting flux SJ101 is light gray spherical particles of 10-60 meshes, and the water content is less than or equal to 0.10%.

The invention also provides a welding method of the composite mixed submerged arc welding flux, which is characterized in that the composite mixed submerged arc welding flux is matched with a welding wire H10Mn2 to be used in the submerged arc welding method.

Preferably, the ratio of the weight of the welding wire to the total weight of the sintered flux HJ431 and the fused flux SJ101 is 1: 1.3.

Preferably, the welding object is Q390BGJ-Z15 steel.

The composite mixed submerged-arc welding flux provided by the invention mixes and combines the sintered flux HJ431 and the smelted flux SJ101, and is matched with an H10Mn2 welding wire for use aiming at a specific welding object Q390BGJ-Z15 steel, so that the composite mixed submerged-arc welding flux is suitable for submerged-arc welding of a ship-shaped part, a cross-shaped part, a butt joint part and other joint parts of a factory component, and finally the obtained welding line has good formability, slag removal performance and mechanical property, is attractive in appearance, improves the impact toughness of deposited metal and improves the welding process performance; the energy consumption is less, the price of the welding flux is relatively lower, the production cost is effectively reduced, and harmful gas generated during welding is reduced.

Compared with the prior art, the invention has the advantages that: the submerged arc welding flux has the advantages of good welding line performance, lower cost, less generated harmful gas and less environmental pollution.

Drawings

FIG. 1 is a schematic representation of a weld joint after welding using the flux of example 1;

FIG. 2 is a crystallographic phase diagram of a weld joint after welding with the flux of example 1;

FIG. 3 is a schematic representation of a weld joint after welding using the flux of example 2;

FIG. 4 is a crystallographic phase diagram of a weld joint after welding with the flux of example 2;

Detailed Description

The technical solutions of the present invention will be described clearly and completely below, and it should be understood that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Sintered flux HJ431 and welding wire H10Mn2 used in the following examples and comparative examples were purchased from Jinqiao welding materials group, Inc. of Tianjin, and fused flux SJ101 was purchased from Kintao welding materials, Inc. of Ischuan county; the sintered flux HJ431 is 30-40 mesh brown red glass-shaped particles, and the water content is less than or equal to 0.10 percent; the smelting flux SJ101 is light gray spherical particles of 40-50 meshes, and the water content is less than or equal to 0.10%.

Example 1

The submerged arc welding flux for composite mixing provided in this example was sintered flux HJ431 and fused flux SJ101 as raw materials, and the weight ratio was 7: 1.

Example 2

The submerged arc welding flux for composite mixing provided in this example was sintered flux HJ431 and fused flux SJ101 as raw materials, and the weight ratio was 5.5: 1.

Example 3

The submerged arc welding flux for composite mixing provided in this example was sintered flux HJ431 and fused flux SJ101 as raw materials, and the weight ratio was 8: 1.

Comparative example 1

The composite mixed submerged-arc welding flux provided by the comparative example comprises the raw materials of sintered flux HJ431 and smelted flux SJ101, and the weight ratio is 3: 1.

Comparative example 2

The submerged arc welding flux for composite mixing provided in this example was sintered flux HJ431 and fused flux SJ101 as raw materials, and the weight ratio was 4: 1.

Comparative example 3

The submerged arc welding flux for composite mixing provided in this example was sintered flux HJ431 and fused flux SJ101 as raw materials, and the weight ratio was 9: 1.

Test example: weld performance testing

The welded steel materials selected in the above examples and comparative examples are steel materials (steel beams) Q390BGJ-Z15 and Q355B purchased from the Steel Limited liability company of dancing Yang, and the adopted submerged arc welding method specifically comprises the following steps: assembling web plates of flange plates of the H-shaped steel beam, and then turning to H-shaped ship-shaped welding for welding. The sintered flux HJ431 and the fused flux SJ101 are mixed in proportion before welding. And (3) after mixing, loading the mixture into a flux hopper of the flux, opening a flux valve to start submerged-arc welding, and cooling and removing the slag to be welded after welding.

The appearance and crystal phase diagrams of the weld joint welded by the flux of example 1 are shown in fig. 1 and 2, respectively, and the appearance and crystal phase diagrams of the weld joint welded by the flux of example 2 are shown in fig. 3 and 4, respectively.

As can be seen from FIGS. 1 and 3, the flux prepared by using the weight ratio of the sintered flux HJ431 to the smelted flux SJ101 of the above example has very stable electric arc, no impurities in the welding process and soft electric arc; the whole slag can be automatically removed easily; no air hole and indentation appear during welding; the transition between welding beads and base metal is smooth, and the welding bead metal and the base metal are well fused together without depressions; the surface of the welding bead is very smooth, has no pockmark and is beautiful in forming. In contrast, the flux prepared by using the sintered flux HJ431 and the fused flux SJ101 of comparative examples 1 to 3 in the weight ratio had problems of more or less pockmarks, non-smoothness, and the like on the surface of the weld.

In general, the closer or equal the properties of the joint are to those of the base material during welding, the better the weld quality and the less likely cracks are to occur. The structure and performance of weld metal and a heat affected zone of a welding joint have different degrees from those of a base metal due to the action of welding heat. For example, submerged arc welding reduces joint impact toughness due to high heat input, slow cooling, and coarse grains in the weld and heat affected zone. As can be seen from FIGS. 2 and 4, the flux prepared by using the weight ratio of the sintered flux HJ431 to the smelted flux SJ101 of the above example has no obvious coarse crystal grains in the crystal phase diagram of the weld joint, and the quality of the weld joint obtained by using the flux of the above example is high.

1. Mechanical Property test

According to the method of the national standard GB50661-2011 steel structure welding specification, the mechanical property test of the welding seam is carried out on the Q390BGJ-Z15 steel and the Q355B steel which are formed by welding the welding fluxes of the examples 1-3 and the comparative examples 1-3.

2. Slag adhesion (slag detachability) phenomenon test

The weld beads of Q390BGJ-Z15 steel and Q355B steel, which were welded using the fluxes of examples 1-3 and comparative examples 1-3, were observed for slag adhesion by visual observation.

3. Sensitivity of weld appearance to parameters

The test results of the mechanical properties, slag detachability and sensitivity of weld appearance to parameters of the welds of the Q390BGJ-Z15 steel and the Q355B steel of the above examples and comparative examples are shown in the following tables 1 and 2.

TABLE 1Q 390BGJ-Z15 test results of steel properties

TABLE 2Q 355B Steel Performance test results

	Mechanical properties	Degree of sensitivity of appearance forming to parameters	Slag sticking phenomenon
				Example 1	Not meet the requirements of	Is relatively sensitive	Local sticking slag
Example 2	Not meet the requirements of	Sensitivity of	Slag sticking
				Example 3	Not meet the requirements of	Is relatively sensitive	Local sticking slag
Comparative example 1	Not meet the requirements of	Sensitivity of	Slag sticking
				Comparative example 2	Not meet the requirements of	Sensitivity of	Slag sticking
Comparative example 3	Not meet the requirements of	Sensitivity of	Slag sticking

As can be seen from the above tables 1 and 2 and the accompanying drawings, the composite mixed submerged arc welding flux prepared by the mixing ratio of the sintered flux HJ431 and the smelted flux SJ101 can effectively improve the performance of a weld joint aiming at Q390BGJ-Z15, and has more attractive appearance of the weld joint and better microstructure of a microcrystalline phase. When the sintered flux HJ431 and the fused flux SJ101 of the same amount are used for the Q355B steel, the problems of slag removal, unsatisfactory mechanical properties and the like occur to different degrees.

Claims

1. The composite mixed submerged-arc welding flux is characterized by comprising a sintered flux HJ431 and a smelted flux SJ101, wherein the weight ratio of the sintered flux HJ431 to the smelted flux SJ101 is 5.5-8: 1.

2. The composite mixed submerged arc welding flux as set forth in claim 1, wherein the weight ratio of the sintered flux HJ431 to the melted flux SJ101 is 7: 1.

3. The composite mixed use submerged arc welding flux according to claim 1, characterized in that the sintered flux HJ431 is red brown glass-like particles of 8-40 mesh with a water content of 0.10% or less; the smelting flux SJ101 is light gray spherical particles of 10-60 meshes, and the water content is less than or equal to 0.10%.

4. The welding method using the composite mixed submerged arc welding flux as set forth in claim 1, wherein the flux is used in a submerged arc welding method in combination with a welding wire H10Mn 2.

5. The welding method as claimed in claim 4, wherein the ratio of the weight of the welding wire to the total weight of sintered flux HJ431 and smelted flux SJ101 is 1: 1.3.

6. The welding method according to claim 5, wherein the welding object is a steel material Q390 BGJ-Z15.