CN115815884A - Marine efficient and environment-friendly submerged-arc welding sintered flux and preparation method thereof - Google Patents

Abstract

The invention relates to a high-efficiency environment-friendly submerged arc welding sintered flux for ships, which is prepared from magnesium oxide (MgO) and fluorite (CaF) ₂ ) Silicon dioxide (SiO) ₂ ) The flux is a main component, wherein the content of the main component reaches more than 80%, and the flux formula contains higher magnesium oxide (MgO) and fluorite (CaF 2), so that the solidification time of a molten pool is short, and the optimal balance between the mechanical property of a welding seam and the welding manufacturability is favorably achieved. Magnesium oxide (MgO) and fluorite (CaF) in flux ₂ ) High content, providing flux capable of bearing large current, and combining certain silicon dioxide (SiO) ₂ ) The welding flux is suitable for larger welding voltage, and meanwhile, a small amount of alloy powder is added into the formula of the welding flux to protect elements such as alloy silicon and manganese, so that the coarseness of a weld joint structure can be inhibited, and the crack resistance of the weld joint is improved.

Description

Marine efficient environment-friendly submerged-arc welding sintered flux and preparation method thereof

Technical Field

The invention relates to the technical field of efficient submerged-arc welding for hull manufacturing, in particular to a marine efficient environment-friendly submerged-arc welding sintered flux used for a medium plate submerged-arc automatic welding process and a preparation method thereof

Background

With the development of shipbuilding industry, the demands of container ships, bulk carriers and the like are increasing, submerged arc automatic welding is also developed from thin plate (t =7-18 mm) welding to thick plate (t =15-55 mm) submerged arc welding, and the welding quantity required by production is increasing continuously.

Flux-wire combinations according to the submerged-arc welding currently used, e.g. wire H10Mn ₂ The diameters of phi 2.0mm, phi 3.0mm, phi 4.0mm and phi 5.0mm are matched with SJ101 sintered flux, and in order to ensure the welding mechanics, especially the impact toughness, the welding current is normally less than 800A, and a reverse carbon planing, a back gouging process and a small current multi-pass welding process parameter are required to be adopted. The welding mode has the defects of low welding efficiency, toxic gas, particle dust, noise, arc light and the like generated in welding and environmental pollution. In the foreign shipbuilding process, for example, japan, korea and the like successively adopt new processes of welding flux, welding wire combination and the like without digging carbon on the reverse side and back chipping, but China still has a blank in this respect.

At present, the welding technical difficulties of the combination of the environment-friendly submerged arc welding flux and welding wires are in the following aspects:

1. when the diameter of a submerged arc welding wire reaches phi 6.4mm and the energy of a welding line is large, the welding current I = 800-1200A, the t of a welded steel plate is required to be less than or equal to 30mm, and according to a normal design scheme, when the front side and the back side are welded in a single way, the mechanical property, particularly the welding toughness, of a welding joint required by design is met when the defects of air holes, slag inclusion, burning-through and the like are not generated on the back side. As the general condition is improved along with the welding current, the welding structure is coarse, harmful precipitation is easy to cause, and the mechanical property requirement of welding can not be met.

2. The flux is matched with H10Mn2 and the diameter of a welding wire with the diameter of 6.4mm, can ensure the back molding and no carbon planing, and can ensure that the mechanical property of a welding line can meet the requirement of 3Y (-20 ℃, and the impact energy is more than or equal to 34), and is a technical key of the efficient submerged arc flux.

Disclosure of Invention

One of the technical problems to be solved by the invention is to overcome the technical difficulty and break through the monopoly abroad to provide the marine high-efficiency environment-friendly submerged arc welding sintered flux, the welding wire of the marine high-efficiency environment-friendly submerged arc welding sintered flux is matched with the diameter phi 6.4mm and H10Mn2, the marine high-efficiency environment-friendly submerged arc welding sintered flux replaces the foreign Korean sintered flux welding wire, the submerged arc welding process performance of the domestic medium plate (t =10-55 mm) is simultaneously met, the mechanical property of a welding joint is ensured to be excellent, and the mechanical property meets the standard requirement of a classification society.

The invention provides a marine high-efficiency environment-friendly submerged-arc welding sintered flux which is matched with a switch and has the diameter of phi 6.4mm and H10Mn2, has the welding current of I = 800-1200A and can bear large linear energy.

The invention also provides a preparation method of the marine high-efficiency environment-friendly submerged-arc welding sintered flux.

The technical problem to be solved by the invention can be realized by the following technical scheme:

the invention relates to a high-efficiency environment-friendly submerged-arc welding sintered flux for ships, which is prepared from magnesium oxide (MgO) and fluorite (CaF) ₂ ) Silicon dioxide (SiO) ₂ ) The flux is a main component, wherein the content of the main component reaches more than 80%, and the flux formula contains higher magnesium oxide (MgO) and fluorite (CaF 2), so that the solidification time of a molten pool is short, and the optimal balance between the mechanical property of a welding seam and the welding manufacturability is favorably achieved. Magnesium oxide (MgO) and fluorite (CaF) in flux ₂ ) High content, providing flux capable of bearing large current, and combining certain silicon dioxide (SiO) ₂ ) The welding flux is suitable for larger welding voltage, and meanwhile, a small amount of alloy powder is added into the formula of the welding flux to protect elements such as alloy silicon and manganese and the like, so that the thick structure of a welding seam can be inhibited, and the crack resistance of the welding seam is improved.

The invention relates to a high-efficiency environment-friendly submerged arc welding sintered flux for ships, which is prepared by mixing magnesia, fluorite, silicon dioxide, zircon sand, iron powder, marble, ferrosilicon, ferromanganese, ferromolybdenum, ferrotitanium, aluminum oxide and 20% potassium-sodium water glass, granulating, drying and sintering, wherein the used raw materials comprise the following components in percentage by mass:

30-40% of magnesia, 25-35% of fluorite, 10-20% of silicon dioxide, 2-4% of zircon sand, 5-10% of iron powder, 1-2% of ferrosilicon, 1.0-2.0% of ferromanganese, 0.5-1.0% of ferromolybdenum, 0.5-1.0% of ferrotitanium and 20-30% of bauxite, wherein the potassium-sodium ratio of potassium-sodium water glass is 1: 1, the modulus is 2.5, and the baume degree is 40-45.

In a preferred embodiment of the present invention, the magnesite is: mgO more than or equal to 90 percent and SiO ₂ ≤5％,S≤0.03％,P≤0.08％。CaO≤1％。

In a preferred embodiment of the present invention, the fluorite is: caF ₂ ≥90％,SiO ₂ ≤8.5％ S≤0.045％,P≤0.02％。

In a preferred embodiment of the present invention, the zircon sand is: zrO (ZrO) ₂ ≥60％,SiO ₂ ≤25％,S≤0.05％,P≤0.05％。

In a preferred embodiment of the invention, the ferrosilicon is: more than or equal to 75 percent of Si, less than or equal to 0.02 percent of S, less than or equal to 0.04 percent of P, and the balance of iron powder.

In a preferred embodiment of the present invention, the ferromanganese is: more than or equal to 80 percent of Mn, less than or equal to 0.02 percent of S and less than or equal to 0.3 percent of P.

In a preferred embodiment of the present invention, the ferromolybdenum is: mo is more than or equal to 45 percent, S is less than or equal to 0.15 percent, and P is less than or equal to 0.1 percent.

In a preferred embodiment of the invention, the ferrotitanium is: more than or equal to 30 to 45 percent of Ti, less than or equal to 0.03 percent of S and less than or equal to 0.05 percent of P.

In a preferred embodiment of the present invention, the iron powder is: fe is more than or equal to 98 percent and SiO ₂ ≤25％,S≤0.025％,P≤0.02％。

In a preferred embodiment of the invention, the marble is: caCO ₃ ≥95％,S≤0.03％,P≤0.03％。

In a preferred embodiment of the invention, the raw materials are mixed by the following raw materials by mass percent: 35% of magnesia, 30% of fluorite, 10% of silicon dioxide, 3% of zircon sand, 10% of iron powder, 2% of marble, 2% of ferrosilicon, 1% of ferromanganese, 1.5% of ferromolybdenum, 0.5% of ferrotitanium and 3.5% of bauxite.

The production method of the marine high-efficiency environment-friendly submerged arc welding sintered flux comprises the following steps:

(1) Weighing various raw materials in the solder according to a proportion to obtain actually required granularity;

(2) Then, after sieving, dry mixing is carried out according to the weight ratio;

(3) After mixing, fully mixing, adding 20% of potassium-sodium water glass, and carrying out wet stirring;

(4) Granulating by adopting a granulator;

(5) Drying the granulated particles in a low-temperature furnace at a low temperature of between 200 and 400 ℃;

(6) Sieving the dried flux to 10-60 meshes;

(7) Sintering at 600-800 deg.c in a high temperature furnace;

(8) Then cooling and weighing;

(9) Then transferring the mixture into a container with good sealing performance and moisture resistance for storage;

(10) Considering that the anti-destruction strength is high in the transportation process, namely, the steel pipe is selected to be transferred into the iron pipe;

(11) Finally, the quality guarantee amount is provided for welding use of the customer.

The invention has the beneficial effects that:

the welding flux disclosed by the invention is completely matched with a H10Mn2 welding wire with the diameter of phi 6.4mm, is used for submerged-arc welding of carbon steel and low-alloy steel, can completely replace the performance of imported like products, meets the submerged-arc welding process with the plate thickness of t =55mm or less, meets the requirement of classification society on the physicochemical property of a welding joint, and reduces the dependence on foreign welding flux; compared with the traditional SJ101 sintering welding matched welding wire with the diameter of phi 6.4mm and H10Mn2, the welding wire can improve the welding efficiency, and reduces the damage of dust, noise and the like caused by carbon planing to the environment and the health of personnel due to different carbon planes, thereby achieving the requirements of high efficiency and environmental protection.

The flux contains a large amount of magnesium oxide and fluoride (MgO + CaF 2) with high content, ensures that a molten pool generates a large amount of volatile gas in a liquid state, is beneficial to fully stirring the liquid molten pool, reduces the risk of coarse weld joint structures, and can also reduce the addition of nonferrous metal oxide manganese ore harmful to human bodies in the flux, and in addition, the addition of CO2 in the welding molten pool reduces the proportion of the content of H in the molten pool, reduces the content of H in the weld joint and delays the risk degree of cracks.

Drawings

FIG. 1 is a schematic diagram of weld joint groove preparation.

FIG. 2 is a metallographic representation of a weld joint numbered M191128-2.

FIG. 3 is a metallographic representation of a weld joint numbered 200115-30.

Detailed Description

The present invention is described in detail below with reference to specific examples, which are merely illustrative of the present invention and do not limit the scope of the claims of the present invention.

The flux is prepared from a solder and 20 wt% of sodium-potassium water glass (the ratio of potassium to sodium is 1: 1, the modulus is 2.8, and the Baume degree is 40-45), wherein the solder is prepared by mixing the following raw materials in percentage by mass:

weighing each raw material in the solder according to a proportion to obtain the granularity which is actually required, sieving, feeding and mixing the raw materials according to the weight ratio, adding 20 percent potassium-sodium water glass, carrying out wet stirring, then granulating by using a granulator, and drying the granulated mixed granular flux at a low temperature of 200-300 ℃ in a low-temperature furnace. Sieving the dried welding machine to 12-48 meshes, sintering at 600-800 deg.C in a high-temperature furnace, sieving, cooling, and packaging into a sealed iron tube with good moisture resistance and high breaking strength during storage and transportation.

The solder weight ratios of the examples are shown in Table 1

TABLE 1

Composition (I)	Example 1 (Kg)	Example 2 (Kg)	Example 3 (Kg)
				Magnesite clinker	30	35	40
Fluorite	35	30	25
				Silicon dioxide	20	10	15
Zircon sand	2	4	5
				Iron powder	5	10	8
CaCO 3	3	5	2
				Silicon iron	2	105	1
Ferromolybdenum	1	0.5	0.8
				Ferromanganese iron	105	2	1
Ferrotitanium	1	0.8	0.5

The submerged arc sintered flux obtained in examples 1-3 of Table 1 of the present invention was used in a welding test matched with a domestic Phi 6.4mm, H10Mn2 welding wire, and the detailed test conditions were as follows:

TABLE 2

Device name	Welder signal	Quantity (table)	Manufacturer of the product
				M submerged arc welding equipment	MZ-1250(DC)	1	SHANGHAI SHIWEI WELDING INDUSTRY Co.,Ltd.

The specifications and components of the welding wire are shown in Table 3

TABLE 3

Steel sheet for testing

The grade and specification of DH36 as a steel sheet material for the test are shown in Table 4

TABLE 4

Test number	Grade	C	Si	Mn	P	S
							Example 1		0.16	0.32	1.35	0.015	0.0034
Example 2	T＝30mm	0.15	0.27	1.35	0.014	0.0040
							Example 3		0.14	0.25	1.29	0.013	0.006

The properties of the weld joint are shown in table 5,

TABLE 5

The properties of the welded joints are shown in Table 6

TABLE 6

And (3) analyzing test results:

as can be seen from the table, the submerged arc welding of the invention for the submerged arc welding of the double-sided single pass welding of the ship plate with DH36 and t =30mm can obtain good mechanical performance, meet the evaluation requirements of the ship DH36, and has the advantages of high strength, elongation, impact toughness and large margin. From the chemical composition, C, mn and Si in the welding seam are stable and reasonable.

The test results show that the welding flux contains a large amount of magnesium oxide, fluorite, bauxite and the like, so that not only can excellent welding process performance be obtained, but also stable chemical components and structures of weld metal can be obtained, and the determined performance is stable.

Claims (12)

1. The marine high-efficiency environment-friendly submerged-arc welding sintered flux is characterized by being prepared from magnesia, fluorite, silicon dioxide, zircon sand, iron powder, marble, ferrosilicon, ferromanganese, ferromolybdenum, ferrotitanium, aluminum oxide and 20% potassium-sodium water glass through mixing, granulating, drying and sintering, and the used raw materials are as follows in percentage by mass:

30-40% of magnesia, 25-35% of fluorite, 10-20% of silicon dioxide, 2-4% of zircon sand, 5-10% of iron powder, 1-2% of ferrosilicon, 1.0-2.0% of ferromanganese, 0.5-1.0% of ferromolybdenum, 0.5-1.0% of ferrotitanium and 20-30% of bauxite, wherein the potassium-sodium ratio of potassium-sodium water glass is 1: 1, the modulus is 2.5, and the baume degree is 40-45.

2. The marine high-efficiency environment-friendly submerged arc welding sintered flux as defined in claim 1, which is characterized in that: the magnesite is prepared from the following components: mgO is more than or equal to 90 percent, and SiO ₂ ≤5％,S≤0.03％,P≤0.08％。CaO≤1％。

3. The marine high-efficiency environment-friendly submerged arc welding sintered flux as defined in claim 1, which is characterized in that: the fluorite is as follows: caF ₂ ≥90％,SiO ₂ ≤8.5％S≤0.045％,P≤0.02％。

4. The marine high-efficiency environment-friendly submerged arc welding sintered flux as defined in claim 1, which is characterized in that: the zircon sand comprises: zrO (ZrO) ₂ ≥60％,SiO ₂ ≤25％,S≤0.05％,P≤0.02％。

5. The marine high-efficiency environment-friendly submerged arc welding sintered flux as defined in claim 1, characterized in that: the ferrosilicon is as follows: more than or equal to 75 percent of Si, less than or equal to 0.02 percent of S, less than or equal to 0.04 percent of P, and the balance of iron powder.

6. The marine high-efficiency environment-friendly submerged arc welding sintered flux as defined in claim 1, which is characterized in that: the ferromanganese is as follows: more than or equal to 80 percent of Mn, less than or equal to 0.02 percent of S and less than or equal to 0.3 percent of P.

7. The marine high-efficiency environment-friendly submerged arc welding sintered flux as defined in claim 1, which is characterized in that: the ferromolybdenum is as follows: mo is more than or equal to 45 percent, S is less than or equal to 0.15 percent, and P is less than or equal to 0.1 percent.

8. The marine high-efficiency environment-friendly submerged arc welding sintered flux as defined in claim 1, characterized in that: the ferrotitanium is as follows: more than or equal to 30 to 45 percent of Ti, less than or equal to 0.03 percent of S and less than or equal to 0.05 percent of P.

9. The marine high-efficiency environment-friendly submerged arc welding sintered flux as defined in claim 1, which is characterized in that: the iron powder is as follows: fe is more than or equal to 98 percent and SiO ₂ ≤25％,S≤0.025％,P≤0.02％。

10. The marine high-efficiency environment-friendly submerged arc welding sintered flux as defined in claim 1, which is characterized in that: the marble is as follows: caCO ₃ ≥95％,S≤0.03％,P≤0.03％。

11. The marine high-efficiency environment-friendly submerged arc welding sintered flux as defined in claim 1, which is characterized in that: the raw materials are mixed by the following mass percent:

35% of magnesia, 30% of fluorite, 10% of silicon dioxide, 3% of zircon sand, 10% of iron powder, 2% of marble, 2% of ferrosilicon, 1% of ferromanganese, 1.5% of ferromolybdenum, 0.5% of ferrotitanium and 3.5% of aluminum oxide.

12. The production method of the marine high-efficiency environment-friendly submerged arc welding sintered flux as set forth in any one of claims 1 to 11, characterized by comprising the following steps:

(1) Weighing various raw materials in the solder according to a proportion to obtain actually required granularity;

(2) Then, after sieving, dry mixing is carried out according to the weight ratio;

(3) After mixing, fully mixing, adding 20% of potassium-sodium water glass, and carrying out wet stirring;

(4) Granulating by adopting a granulator;

(5) Drying the granulated particles in a low-temperature furnace at a low temperature of between 200 and 400 ℃;

(6) Sieving the dried flux to 10-60 meshes;

(7) Sintering at 600-800 deg.c in a high temperature furnace;

(8) Then cooling and weighing;

(9) Then transferring the mixture into a container with good sealing performance and moisture resistance for storage;

(10) Considering that the anti-destruction strength is high in the transportation process, namely, the steel pipe is selected to be transferred into the iron pipe;

(11) Finally, the quality guarantee amount is provided for welding use of the customer.

Images