TWM531875U - Welding protective atmosphere device for high frequency welding pipe manufacturing - Google Patents

Description

Welding protection atmosphere device for high frequency welding pipe

The present invention relates to a welding protection atmosphere device, and more particularly to a welding protection atmosphere device for a high-frequency welding (ERW) pipe.

Electric Resistance Welding (ERW) is one of the most widely used welding techniques in the current steel tube manufacturing industry. However, in the welding process, the welding parameters of the steel itself are often improperly adjusted due to the alloy composition design or the welding process, so that the weld bead is mixed with oxide slag such as F ₂ O ₃ , Cr ₂ O ₃ , SiO ₂ or MnO ₂ . The properties such as strength, elongation, flaring rate and low temperature impact toughness of the steel pipe bead are degraded. Therefore, it is necessary to seek a solution.

Therefore, the object of the present invention is to provide a welding protection atmosphere device for high-frequency welding pipe production.

Therefore, the welding protection atmosphere device for the high-frequency welded pipe is suitable for a high-frequency welded pipe car and a shielding gas supply device, and comprises a protective cover, a protective gas pipe and a shielding gas. The protective cover is disposed at a welding section of the high-frequency welded pipe and includes a top wall and a surrounding wall extending downward from a periphery of the top wall. The top wall has a through hole extending from the upper surface thereof to the lower surface, and the surrounding wall has a gas accommodating space communicating with the through hole. The shielding gas pipe is interposed between the shielding gas supply device and the protective cover, and two ends thereof are respectively connected to the shielding gas supply device and the through hole of the top wall of the protective cover. The shielding gas is supplied by the shielding gas supply device and flows through the shielding gas pipe into the gas accommodating space of the surrounding wall of the protective cover to cover the welding section position of the high-frequency welded pipe.

The utility model has the advantages that the protective gas is introduced into the gas accommodating space of the protective cover to cover the welding section, thereby reducing the proportion of oxide formation, thereby reducing the probability of the weld bead being mixed with the oxide slag, and Effectively improve the low temperature impact toughness of steel pipe bead.

Before the present invention is described in detail, it should be noted that in the following description, similar elements are denoted by the same reference numerals.

Referring to Fig. 1, the embodiment of the welding atmosphere device 1 for high-frequency welding (ERW) pipe is suitable for a high-frequency welded pipe car 8, a protective gas supply device (not shown) and a steel pipe to be welded 9. The high-frequency welded tube car 8 includes two pressing rollers 81 and an induction coil 82 and the like. The steel pipe to be welded 9 enters the high-frequency welded pipe car 8 in the moving direction of the steel pipe as indicated by the arrow A to perform the ERW welding process.

In the present embodiment, the welding atmosphere device 1 for high-frequency welded pipe assembly comprises a protective cover 11, a protective gas pipe 12, a shielding gas (not shown) and at least one screw 13.

The protective cover 11 is disposed at a welding section position of the high-frequency welded tube car 8. In the present embodiment, if the distance between the induction coil 82 and the center of the pressing rolls 81 is D, the new welding protection atmosphere device 1 should be placed at a distance of about D/3 from the center of the pressing rolls 81. The position is located about 30 to 40 mm above the steel pipe to be welded 9. In the present embodiment, the protective cover 11 is made of Teflon.

Referring to Figures 1 to 3, the shape of the protective cover 11 conforms to the direction in which the tube is actuated, which increases the coverage of the shielding gas and isolates the splashing effect of the cooling water of the pressing roller 81. As shown in FIG. 3, in the present embodiment, the protective cover 11 includes a top wall 111 and a surrounding wall 112 extending downward from the periphery of the top wall 111. The top wall 111 has a through hole 110 extending from the upper surface thereof to the lower surface, and two screw holes 118 penetrating inwardly from the side surface thereof to the through hole 110 and respectively corresponding to the screws 13. The screws 13 are screwed into the two screw holes 118 to lock the shielding gas pipe 12, respectively. In other variations of the embodiment, the number of the screw holes 118 and the corresponding screws 13 may be only one.

The surrounding wall 112 has a gas receiving space 119 communicating with the through hole 110. In the present embodiment, the surrounding wall 112 includes a rectangular section 1121 extending vertically downward from the top wall 111, and a ramp section 1122 extending horizontally from the rectangular section 1121.

As shown in FIG. 1 and FIG. 2, the shielding gas pipe 12 is interposed between the shielding gas supply device and the protective cover 11, and the two ends thereof are respectively connected to the shielding gas supply device and the top wall 111 of the protective cover 11. The through hole 110. In the present embodiment, the protective gas tube 12 is a copper tube, and the through hole 110 has a circular cross section, and the protective gas tube 12 is a circular tube.

The shielding gas is supplied from the shielding gas supply device and flows through the shielding gas tube 12 into the gas accommodating space 119 of the surrounding wall 112 of the protective cover 11 to cover the high-frequency welded tube car 8 Welding section position. The density of the shielding gas is greater than the density of the air to achieve a protective effect by gas settling. In the present embodiment, the shielding gas may be, for example, argon or carbon dioxide, and the pressure of the shielding gas is 100 kgf/cm ² and the flow rate of the shielding gas is ²⁵ l/min at 20 ° C.

In the present embodiment, the protective gas tube 12 is a 5/8 inch copper tube which is inserted into the through hole 110 of the top wall 111 of the protective cover 11 and is passed through the shielding gas to have an insulating effect to avoid the high frequency welding. The welded section of the tube 8 is splashed by the cooling water (not shown) of the squeeze roller 81, and has the effect of concentrating the shielding gas on the welded section. The size of the protective cover 11 and the protective gas tube 12 can be scaled according to different tube sizes or space constraints of the tube 8 . The material of the protective cover 11 can be Teflon, which has the advantages of high temperature resistance, anti-inductive and anti-magnetic.

In the present embodiment, the installation method and the operation procedure of the present invention on the high-frequency welded tube car 8 are described in the following.

First, the high-frequency welded tube car 8 needs to be pre-adjusted with suitable welding parameters, such as welding speed, welding voltage, and weld bead extrusion stream.

Next, the shielding gas supply device (for example, a protective gas cylinder) is connected to one end of the protective gas tube 12 (for example, a 5/8 inch copper tube and has a thickness of 0.8 mm), and the protective gas tube 12 is The other end is connected to the through hole 110 of the top wall 111 of the protective cover 11, and the protective cover 11 is fixedly mounted on the welding section of the high-frequency welded tube car 8. If the distance between the induction coil 82 and the center of the pressing rolls 81 is D, the new welding protection atmosphere device 1 should be placed at a position about D/3 from the center of the pressing rolls 81, and About 30 to 40 mm above the steel pipe 9 to be welded.

Next, a shielding gas such as argon gas or carbon dioxide is introduced into the gas accommodating space 119 of the surrounding wall 112 at a pressure of 100 kgf/cm ² and a flow rate of ²⁵ l/min under a temperature of 20 °C.

Next, the high-frequency welded tube car 8 is started and welded, as shown in FIG.

Then, when the pipe making operation is completed, the shielding gas supply device is turned off, and the supply of the shielding gas is stopped.

In order to test the steel pipe produced under the protection of the welding protection atmosphere device 1 of the present invention, the inventor of the present invention tested the steel pipe of API_5L_PSL2_X70M (Φ16 inch/thickness 9.5 mm). Experiment A used argon gas, and Experiment B used carbon dioxide to compare with the case where the novel welding atmosphere device 1 was not used. In each of the three cases, three test pieces of the weld bead were taken after the pipe making, and the low temperature impact test was carried out at 0 ° C according to the API standard test method to evaluate the difference in the quality of the weld bead.

Table 1 below shows the average impact toughness value of 0 °C of Experiment A = 48.6 J, and the average impact toughness value of 0 ° C of Experiment B = 41.0 J, which all meet the specifications of API steel pipe. However, the 0°C average impact toughness value of the new welding protection atmosphere device 1 is not found to be 15.9J, which indicates that the weld bead quality of the steel pipe in this case does not meet the specifications of the API steel pipe. Therefore, the experimental results show that the choice of argon or carbon dioxide gas as the welding protection atmosphere has the effect of improving the low temperature impact toughness of the weld bead, and the protection effect of argon is the best.

Table 1 Comparison results of experiment A/B and no welding atmosphere protection device:         <TABLE border="1" borderColor="#000000" width="_0001"><TBODY><tr><td> Item</td><td> 0°C impact toughness value (J) </td><td > Test Mean (J) and Judgment Results</td><td> API Specification Requirements (J) </td></tr><tr><td> Experiment A </td><td> 55.3 </td ><td> 48.6(Qualified) </td><td> Three pieces average >27, and need two pieces >27, the third piece must be no less than 20.25 </td></tr><tr><td> 36.6 </td></tr><tr><td> 54.0 </td></tr><tr><td> Experiment B </td><td> 48.1 </td><td> 41.0 (Qualified ) </td></tr><tr><td> 44.5 </td></tr><tr><td> 30.5 </td></tr><tr><td> No welding atmosphere Device</td><td> 11.9 </td><td> 15.9 (failed) </td></tr><tr><td> 22.4 </td></tr><tr><td> 13.3 </td></tr></TBODY></TABLE>

In summary, when the welding protection atmosphere device 1 of the present invention is used in the ERW pipe welding process, a gas such as argon or carbon dioxide may be used to cover the welded portion to reduce the proportion of oxide formation, thereby reducing the weld bead. The probability of mixing the oxide slag and the low-temperature impact toughness of the steel pipe bead can be effectively improved, so the purpose of the novel can be achieved.

However, the above is only the embodiment of the present invention, and when it is not possible to limit the scope of the present invention, all the simple equivalent changes and modifications according to the scope of the patent application and the contents of the patent specification are still This new patent covers the scope.

1‧‧‧Welding protective atmosphere device for high frequency welding pipe
11‧‧‧ Protective cover
110‧‧‧through hole
111‧‧‧ top wall
112‧‧‧ Around the wall
1121‧‧‧Rectangular section
1122‧‧‧Slope section
118‧‧‧ screw holes
119‧‧‧ gas accommodation space
12‧‧‧Protective gas tubes
13‧‧‧ screws
8‧‧‧High frequency welded tube car
81‧‧‧Squeeze roller
82‧‧‧Induction coil
9‧‧‧Steel to be welded
A‧‧‧Steel tube moving direction

Other features and effects of the present invention will be apparent from the following description of the drawings, wherein: FIG. 1 is a perspective view showing an embodiment of the welding protective atmosphere device for the high-frequency welded pipe of the present invention and its application. A high-frequency welded tube car and a steel pipe; Fig. 2 is a perspective view showing the design of the protective cover of the embodiment; and Fig. 3 is a cross-sectional view showing the protective cover.

1‧‧‧High frequency welding tube Welding protection atmosphere device

11‧‧‧ Protective cover

12‧‧‧Protective gas tubes

13‧‧‧ screws

8‧‧‧High frequency welded tube car

81‧‧‧Squeeze roller

82‧‧‧Induction coil

9‧‧‧Steel to be welded

A‧‧‧Steel tube moving direction

Claims (11)

A welding protection atmosphere device for high-frequency welding pipe is suitable for a high-frequency welded pipe car and a protective gas supply device, and comprises: a protective cover disposed at a welding section of the high-frequency welded pipe car, and includes a top wall and a surrounding wall extending downward from a periphery of the top wall, wherein the top wall has a through hole extending from the upper surface thereof to the lower surface, the surrounding wall having a gas volume communicating with the through hole a protective gas tube between the protective gas supply device and the protective cover, and two ends of which are respectively connected to the protective gas supply device and the through hole of the top wall of the protective cover; and a protection A gas is supplied from the shielding gas supply device and flows through the shielding gas pipe into the gas accommodating space of the surrounding wall of the protective cover to cover the welding section position of the high-frequency welded pipe. The welding protective atmosphere device for high-frequency welded pipe according to claim 1 is also applicable to a steel pipe to be welded, wherein the protective cover is disposed about 30 to 40 mm above the steel pipe to be welded. The welding atmosphere device for high-frequency welded pipe according to claim 1, wherein the surrounding wall of the protective cover comprises a rectangular segment extending vertically downward from the top wall, and a rectangular segment A beveled section that extends horizontally horizontally. The welding atmosphere device for high frequency welding pipe according to the above item 1, wherein the protective cover is made of Teflon. The welding atmosphere protection device for high frequency welding pipe according to the above item 1, wherein the shielding gas pipe is a copper pipe. The welding atmosphere protection device for high-frequency welding pipe according to Item 1, wherein the through hole has a circular cross section, and the protective gas pipe is a circular pipe. The welding atmosphere protection device for high frequency welding pipe according to Item 1, wherein the shielding gas has a density greater than a density of air. The welding atmosphere protection device for high-frequency welding pipe according to Item 7, wherein the shielding gas is argon gas. The welding atmosphere device for high-frequency welding pipe according to Item 7, wherein the shielding gas is carbon dioxide. The welding atmosphere protection device for high-frequency welding pipe according to Item 1, wherein the pressure of the shielding gas is 100 kgf/cm ² and the flow rate of the shielding gas is ²⁵ l/min. . The welding atmosphere protection device for high-frequency welded pipe according to claim 1, wherein the top wall of the protective cover further has at least one screw hole penetrating inwardly from the side surface thereof to the through hole, and The welding protection atmosphere device further includes at least one screw corresponding to the screw hole, the screw screwing into the screw hole to lock the shielding gas pipe.