TWI538883B - Welding activated flux for structural alloy steels - Google Patents

Description

Welding active agent for alloy steel for construction

This invention relates to a welding active agent, and more particularly to a welding active agent for an alloy steel for construction.

The alloying steel has a carbon content of 0.2 to 0.7% and contains different alloying elements (such as nickel, chromium and molybdenum) depending on its application characteristics to improve its corrosion resistance, high temperature mechanical strength and low temperature impact. Toughness and quenching quality effects. Alloy steel for construction has been widely used in engineering practice such as building bridges, locomotive skeletons, turbine blades, drive shafts, crankshafts and high-tension bolts. Therefore, the mechanical strength and impact toughness of the overall structure are extremely high. When performing welding work, it is necessary to adjust the properties of the alloy steel used for the welding rod (or welding line) and the welding process so that the formed bead can have both high strength and high toughness. The weld bead is damaged by the load.

Tungsten Inert Gas Welding (TIG Welding) is a high quality arc welding process. In the practical application of welding engineering, the welding process of alloy steel for construction is generally carried out mainly by tungsten inert gas welding. The tungsten inert gas welding is under the protection of an inert gas (argon or helium), and an arc is guided by a tungsten rod electrode to generate a welding heat source, and a conventional welding rod is melted at the abutment of the two workpieces (or a conventional welding wire). The molten conventional electrode (or a conventional bonding wire) is formed into a weld pool at the abutment of the two workpieces, and after the cooling pool is cooled and solidified, a weld bead is formed to tightly join the two workpieces, so that The two workpieces form a weldment after welding, and the welding process is completed. However, due to the lower power density of the heat source of the tungsten inert gas welding, a wider and shallow weld pool is formed, resulting in The problem of insufficient weld bead depth when welding thick plate workpieces is not applicable to workpiece welding with thickness greater than 3 mm.

In order to solve the problem of insufficient weld bead depth when welding tungsten thick inert gas to a thick plate workpiece, a workpiece grooving process can be performed before welding. As shown in Fig. 1A, the grooving process is applied to the side edge 91 of a workpiece 9, milled by a milling cutter M to form a bevel 92, and the side edge 91' of the other workpiece 9' is machined in the same manner to form Another slope 92'. Referring to FIGS. 1B and 1C, when welding is performed, the side edges 91, 91' of the two workpieces 9, 9' are abutted, and the two inclined surfaces 92 and 92' form an open angle structure, and a tungsten rod electrode is used. E and a conventional electrode (or a conventional wire) are subjected to a plurality of welding processes at the open angle structure to form a weld bead 93. Although the pre-grooving of the workpiece can increase the depth of the bead 93, the width of the bead 93 is excessively large. In addition, during the welding process, the welding heat source forms a heat-affected zone near the weld, and the heat-affected zone is too large due to the slotting process and multiple welding, in addition to reducing the strength of the obtained weldment, It is easy to deform the weldment. Furthermore, the pre-grooving of the workpiece and subsequent multiple welding operations will add additional production time and manufacturing costs, such as labor, welding rods (or wire), and welding gas.

The present invention provides a welding active agent for alloy steel for construction, and the alloy steel for welding active agent welding structure can increase the depth of the formed bead and reduce the width of the formed bead.

The present invention provides a welding active agent for alloy steel for construction. With the alloy steel for welding active agent welding structure, a weldment having better strength and lower deformation possibility can be obtained.

The invention provides a welding active agent for alloy steel for construction, which comprises 40-50% by weight of cerium oxide, 25-30% of molybdenum trioxide, 5-10% of titanium dioxide, and 10-20% of Chromium oxide.

The welding active agent for alloy steel for the construction of the present invention further comprises 5 to 10% by weight of iron trifluoride.

The welding active agent for alloy steel for structural use of the present invention, wherein the particle size of the welding active agent powder particles is between 53 and 88 μm.

The welding active agent for the alloy steel for structural use of the present invention transmits the distribution ratio of cerium oxide, molybdenum trioxide, titanium oxide and chromium trioxide, and changes the surface tension of the liquid metal in the weld pool when the alloy steel for welding structure is used. The gradient forms a strong external convection from the outside to the inside of the weld pool to achieve the effect of reducing the width of the weld bead.

The welding active agent for the alloy steel for the structure of the present invention transmits the distribution ratio of cerium oxide, molybdenum trioxide, titanium oxide and chromium oxide to increase the current density of the surface of the weld pool when the alloy steel for welding structure is used. A strong upper and lower electromagnetic force is generated inside the weld pool to achieve the effect of improving the weld bead depth.

The welding active agent for alloy steel used in the structure of the invention can increase the depth of the formed bead and reduce the width of the formed bead, resulting in a higher bead aspect ratio, thereby obtaining better strength and lower deformation. The possibility of reducing the production time, by eliminating the need for pre-grooving the workpiece, can reduce the labor waste, welding rod (or welding wire) and welding gas consumption caused by multiple welding processes, Manufacturing costs and labor costs.

〔this invention〕

1, 1'‧‧‧ workpiece

11, 11' ‧ ‧ side edge

12‧‧‧weld

13‧‧‧welding pool

2‧‧‧Welding active agent

3‧‧‧Active electrode (or active wire)

31‧‧‧Extension

B‧‧‧Brush

E‧‧‧Tungsten rod electrode

F‧‧‧Filling metal

[study]

9, 9' ‧ ‧ workpiece

91, 91’‧‧‧ side edge

92, 92’‧‧‧ bevel

93‧‧‧weld

M‧‧‧ milling cutter

E‧‧‧Tungsten rod electrode

W‧‧‧Knowledge welding rod (or conventional welding wire)

Figure 1A: Schematic diagram of the pre-grooving of the workpiece.

Figure 1B: Schematic diagram of pre-grooving and multiple welding operations.

Figure 1C: A cross-sectional view of a weld bead produced by pre-grooving and multiple welding operations.

Fig. 2 is a schematic view showing the application of the welding active agent of the present invention.

Fig. 3A is a perspective structural view (1) of an active electrode (or active bonding wire) made by using the welding active agent of the present invention.

Fig. 3B is a perspective structural view (2) of an active electrode (or active bonding wire) made by using the welding active agent of the present invention.

Fig. 3C is a perspective structural view (3) of an active electrode (or active bonding wire) made by using the welding active agent of the present invention.

Fig. 3D is a perspective structural view (4) of an active electrode (or active bonding wire) made by using the welding active agent of the present invention.

Fig. 4A is a schematic view showing the welding using the active electrode (or active wire) made of the welding active agent of the present invention.

Figure 4B is a cross-sectional view of a weld bead produced by welding using the aforementioned active electrode (or active wire).

Fig. 5A is a schematic view showing the flow of liquid metal in a weld pool without using the welding active agent of the present invention.

Figure 5B is a schematic illustration of the flow of liquid metal in a weld pool using the welding active agent of the present invention.

Fig. 6A is a view showing the appearance of the weld bead of the A0 group experiment of the present invention.

Fig. 6B is a view showing the shape of the weld bead of the group A0 experiment of the present invention.

Fig. 7A is a view showing the appearance of the weld bead of the group A1 experiment of the present invention.

Fig. 7B is a view showing the shape of the bead of the group A1 experiment of the present invention.

Fig. 8A is a view showing the appearance of the weld bead of the group A2 experiment of the present invention.

Fig. 8B is a view showing the shape of the bead of the group A2 experiment of the present invention.

Figure 9A is an appearance view of the weld bead of the A3 group experiment of the present invention.

Fig. 9B is a view showing the shape of the weld bead of the A3 group experiment of the present invention.

Fig. 10A is a view showing the appearance of the bead of the A4 group experiment of the present invention.

Fig. 10B is a view showing the shape of the bead of the group A4 experiment of the present invention.

Fig. 11A is a view showing the appearance of the weld bead of the A5 group experiment of the present invention.

Figure 11B is a view of the weld bead pattern of the A5 group experiment of the present invention.

Fig. 12A is a view showing the appearance of the weld bead of the A6 group experiment of the present invention.

Fig. 12B is a view showing the shape of the weld bead of the A6 group experiment of the present invention.

The above and other objects, features and advantages of the present invention will become more <RTIgt; Alloy steel, which can be AISI 23xx or AISI 25xx series nickel steel; AISI 31xx, AISI 32xx, AISI 33xx or AISI 34xx series of nickel-chromium steel; AISI 40xx or AISI 44xx series of molybdenum steel; AISI 41xx series of chromium-molybdenum Steel; AISI 43xx, AISI 43BVxx, AISI 47xx, AISI 81xx, AISI 86xx, AISI 87xx, AISI 88xx, AISI 93xx, AISI 94xx, AISI 97xx or AISI 98xx series of nickel-chromium-molybdenum steel; AISI 46xx or AISI 48xx series of nickel-molybdenum Steel; AISI 50xx, AISI 51xx or AISI 52xx series of chrome steel; AISI 61xx series of chrome vanadium steel; AISI 9xx series of high strength low alloy steel, etc., which is a general knowledge of the technical field of the invention, and is not limit.

The welding active agent for alloy steel for structural use according to an embodiment of the present invention comprises ceria, molybdenum trioxide, titanium dioxide and chromium trioxide. During the welding process, a welding heat source is provided at the weld to melt the welding active agent. A weld pool is formed between the two workpieces, and a weld bead is formed after the weld pool is cooled and solidified, thereby obtaining a weldment, thereby completing the welding process. By using the welding active agent, the formed bead has a higher depth and a narrower width, that is, the bead has a higher aspect ratio, as described below.

In detail, in the embodiment, the welding active agent may comprise 40-50% by weight of cerium oxide, which can effectively increase the depth of the weld bead and effectively reduce the width of the weld bead. The welding active agent may further comprise 25 to 30% by weight of molybdenum trioxide, which may help to increase the depth of the weld bead. In addition, the welding active agent may comprise 5 to 10% by weight of titanium dioxide, which may help to increase the depth of the weld bead and smooth the surface of the weld bead. The welding active agent may further comprise 10 to 20% by weight The chromium oxide can assist in increasing the depth of the weld bead and can improve the corrosion resistance of the weld bead.

Therefore, the welding active agent of the present embodiment can be used to weld the structural alloy steel with the welding active agent by adding cerium oxide, molybdenum trioxide, titanium oxide or chromium trioxide, and the depth of the welding bead can be effectively improved. Therefore, in the welding process, the cumbersome steps of the pre-grooving process and the subsequent multiple welding processes can be eliminated, and the effect of simplifying the welding process can be achieved.

In addition, the welding active agent of the embodiment may further comprise 5-10% by weight of iron trifluoride, which can reduce the generation of active agent residue and assist in smoothing the surface of the weld bead to achieve an improved appearance of the weld bead surface. The effect.

The distribution ratio of the welding active agent of the present invention is generally known in the technical field of the present invention, and is appropriately adjusted according to the type, characteristics, and welding parameters of the alloy steel for structural welding required, and is not in this embodiment. The limit value is limited.

In this embodiment, the cerium oxide, molybdenum trioxide, titanium dioxide, chromium trioxide and iron trifluoride are preferably in the form of a powder, and the particle size of the powder particles may be between 53 and 88 μm. The mixing uniformity of each component is improved, so that the welding active agent is easily uniformly applied to the surface of the workpiece, and at the same time, due to the small particle size of the powder, the composition of the welding active agent is easily melted by the welding arc during welding, and Effectively increase the depth of the weld bead.

The welding active agent of this embodiment can be subjected to a welding process by any conventional means, for example, using a tungsten inert gas welding method, which is uniformly applied to the surface of the workpiece before welding, as described in detail below.

Referring to FIG. 2, before welding, the side edges 11, 11' of the two workpieces 1, 1' can be abutted, and the welding active agent 2 is applied to the two workpieces by a brush B. The junction of 1'. The welding active agent 2 can be pre-dispersed in a liquid or gel medium, so that the welding active agent can be uniformly applied to the abutment of the two workpieces 1 and 1', and can be carried out after the coating is completed. welding.

In addition, please refer to the 3A, 3B, 3C, 3D drawings, the welding activity of the present invention The agent may be combined with a filler metal F to form a reactive electrode (or active bonding wire) 3, and then the welding operation is performed by a tungsten inert gas welding method. The active electrode (or active bonding wire) 3 may be formed by filling the welding active agent 2 into the interior of the hollow filler metal F (Fig. 3A), or may be surrounded by the welding active agent 2 Formed on the outside of the solid strip-shaped filler metal F (Fig. 3B). Alternatively, the filler metal F may be rolled into a sheet shape to wrap the solder active agent 2 (FIG. 3C); or after the solder active agent 2 is wrapped, the sheet-like filler metal F may form at least one extended end. 31 is extended into the inside of the active electrode (or active bonding wire) 3 (Fig. 3D). By using the active electrode (or active bonding wire) 3, the inconvenience of manually applying the welding active agent can be eliminated, and the welding automation can be applied, and the production efficiency can be greatly improved.

Referring to FIG. 4A, the active electrode (or active wire) 3 can be used to match the tungsten rod electrode E, so that the filler metal F and the welding active agent 2 are co-fused to the two workpieces 1 and 1. The weld pool is formed between the side edges 11, 11', and the weld bead is formed after the weld pool is cooled and solidified. As shown in Fig. 4B, the formed bead 12 is in the form of a deeper depth, a narrower width, and a higher depth and width.

During the welding process, due to the high temperature thermal effect of the arc, liquid metal convection will occur in the weld pool. Referring to FIG. 5A, when the welding active agent is not added, the liquid metal in the weld pool 13 forms an "outer surface tension flow" flowing from the center of the weld pool 13 toward the outer edge thereof, so that the weld bead 12 is formed wide. And the shallow form. Continuing to refer to FIG. 5B, after adding the welding active agent, the surface tension gradient of the liquid metal in the weld pool 13 can be changed, so that the liquid metal forms an "internal surface tension flow flowing from the outer edge of the weld pool 13 toward the center thereof. "." Thereby, the weld pool 13 is caused to reduce the width of the formed weld bead.

The welding active agent can increase the current density of the surface of the weld pool 13 and generate a strong upward and downward electromagnetic force inside the weld pool 13 to increase the depth of the formed weld bead 12. At the same time, the addition of the welding active agent can reduce the heat affected zone and avoid expanding the influence of non-welded proximity. The original structure of the location is made of alloy steel.

In combination with the above mechanism, the pre-grooving process and the multiple welding process of the workpiece are not required, and the welding active agent of the invention can greatly increase the bead depth, thereby achieving the enhancement of the strength of the weldment and the possibility of deformation of the weldment.

In order to prove that the welding active agent of the present invention is used for the alloy steel for welding construction, the depth of the formed bead can be improved, and the pre-grooving process and the multiple welding process of the workpiece can be omitted, thereby saving welding time and cost. The experimental results: the distribution ratio of the welding active agent used in this experiment is shown in Table 1 below, wherein the group A0 is a control group not using the welding active agent; the welding active agent group of the group A1 to A3 comprises two Cerium oxide, molybdenum trioxide, titanium dioxide and chromium trioxide; Groups A4 to A6 contain iron trifluoride in addition to the above components. The powder active agent has a powder particle size ranging from 53 to 88 μm.

In this experiment, alloy steel for AISI 4130 construction was used, and the steel plate size was 100×100×5 mm. Before the welding experiment, the surface contamination of the AISI 4130 structural alloy steel plate was removed in advance with a 240-gauge carbonized crepe paper, and then wiped clean with acetone. Before the welding experiment, the welding active agent powder of the above A1~A6 group and the methanol are formulated into a slurry form, and then the slurry-like welding active agent is applied to the surface of the AISI 4130 structural alloy steel plate by using a brush, waiting The welding experiment can be carried out after the methanol is completely volatilized. The welding method was performed in a single pass bead-on-plate experiment using a tungsten inert gas welding process without the addition of a filler metal. The welding equipment uses a tungsten inert gas welding machine with a constant current source. The tungsten rod is made of ψ3.2mm EWTh-2, the tungsten rod tip angle is 60°, the arc length is 2mm, the welding current is 180A, and the welding speed is 140mm/min. The welding process uses high purity argon as a shielding gas with a flow rate of 15 L/min. After the welding is completed, the welded test piece is cut out, and after the completion of the inlay, it is ground to a number of 1200 with a carbonized crepe paper, and then polished to a thickness of 0.05 μm with alumina powder. After the polishing is completed, the test piece is washed and dried with alcohol, and chemical etching is continued with a 5% Nital solution. Finally, the appearance of the weld bead and the shape of the weld bead were taken with a metallographic microscope, and the weld bead depth and weld bead width were measured.

Please refer to Table 2 for the measured weld bead depth, bead width, and bead aspect ratio after welding with the welding active agent in Groups A0 to A6 of this test. The weld bead depth described herein measures the maximum vertical depth of the weld bead from the weld bead surface. The weld bead width measures the maximum horizontal width of the weld bead surface. The weld bead depth ratio is determined by the weld bead depth divided by the weld bead width. Got it.

Please refer to the 6A and 6B drawings, which are the appearance of the bead of the A0 group and the shape of the bead. The 7A and 7B are the appearance of the bead of the A1 group and the shape of the bead. 8A and 8B show the appearance of the weld bead and the shape of the bead of the A2 group. The drawings of the 9A and 9B show the appearance of the weld bead of the A3 group and the shape of the bead. The 10A and 10B show the group A4. The appearance of the weld bead and the shape of the weld bead, and the drawings of Figs. 11A and 11B show the appearance of the weld bead of the A5 group and the shape of the weld bead. State diagrams, Figures 12A and 12B show the appearance of the weld bead and the shape of the weld bead of Group A6. It can be seen from the above experimental results that the distribution ratio of cerium oxide, molybdenum trioxide, titanium oxide and chromium trioxide in the welding active agent can produce a completely penetrated weld bead (ie, welding) when the alloy steel for welding structure is used. The depth of the track is greater than the thickness of the steel sheet, and the addition of iron trifluoride improves the surface appearance of the weld bead when the alloy steel for the welded structure is used. Compared with the weld bead depth without using the welding active agent, the A1 to A3 group of the welding active agent of the present invention can increase the bead depth of 282 to 289%, and the A4 to A6 group can increase the welding of 295 to 303%. Road depth.

In summary, the welding active agent for alloy steel used in the structure of the present invention transmits the ratio of ceria, molybdenum trioxide, titanium dioxide and chromium trioxide to change the liquid metal in the weld pool when the alloy steel for welding structure is used. The surface tension gradient forms an external convection from the outside to the inside of the weld pool to achieve the effect of reducing the width of the weld bead.

The welding active agent for the alloy steel for the structure of the present invention transmits the distribution ratio of cerium oxide, molybdenum trioxide, titanium oxide and chromium oxide to increase the current density of the surface of the weld pool when the alloy steel for welding structure is used. A strong upper and lower electromagnetic force is generated inside the weld pool to achieve the effect of improving the weld bead depth.

The welding active agent for alloy steel used in the structure of the invention can increase the depth of the formed bead and reduce the width of the formed bead, resulting in a higher bead aspect ratio, thereby obtaining better strength and lower deformation. The possibility of reducing the production time, by eliminating the need for pre-grooving the workpiece, can reduce the labor waste, welding rod (or welding wire) and welding gas consumption caused by multiple welding processes, Manufacturing costs and labor costs.

While the invention has been described in connection with the preferred embodiments described above, it is not intended to limit the scope of the present invention. The technical scope of the invention is protected, and therefore the scope of the invention is defined by the scope of the appended claims.

1, 1'‧‧‧ workpiece

11, 11' ‧ ‧ side edge

2‧‧‧Welding active agent

B‧‧‧Brush

Claims (3)

A welding active agent for alloy steel for structural use, comprising 40-50% by weight of cerium oxide, 25-30% of molybdenum trioxide, 5-10% of titanium dioxide, and 10-20% of trioxide chromium. The welding active agent for alloy steel for construction according to claim 1, wherein the iron trifluoride is further contained in an amount of 5 to 10% by weight. The welding active agent for alloy steel for construction according to the first or second aspect of the invention, wherein the particle size of the welding active agent powder particles of the structural alloy steel is between 53 and 88 μm.