JPS61216871A - Connecting method for thin high tensile steel sheet - Google Patents

Abstract

PURPOSE:To connect satisfactorily thin high tensile steel sheets without generating rupture by interposing a thin low-carbon steel sheet between the ends of the thin high tensile steel sheets, superposing the ends and subjecting the same to pressure resistance welding with contact electrode rollers. CONSTITUTION:The thin low-carbon steel sheet is interposed between the ends of the thin high tensile steel sheet which contain much C, Si and Mn and with which resistance welding is difficult, then the ends are superposed on each other. The superposed parts are pressurized by the contact electrode rollers under conduction of electricity and are thereby resistance-welded. The thin high tensile steel sheets and the thin low-carbon steel sheet are welded by maintaining a good fit between each other. The thin high tensile steel sheet are therefore satisfactorily welded to each other without the possibility to generating the rupture.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Industrial application field
．． 1ch and/or 5i) 0.2% and/or MtL)
1.0%) Ic relates to a method of connecting high tensile strength thin steel plates by resistance welding.

(b) Prior art In general, high tensile strength steel plates are CljeM? Resistance welding is difficult due to the high S content. For this reason, in lines subject to high tension or repeated bending, welding fractures often occur within the line.

Since high-strength steel plates and low-carbon steel plates have relatively good weldability, high-tensile steel plates were connected to low-carbon steel plates on lines subject to high tension or repeated bending. By the way, the fact that the preceding steel plate and the following steel plate are made of different materials often accompanies a change in the working conditions of the line.

For example, in continuous annealing, the annealing temperature conditions are significantly different between a high-strength steel plate and a low-carbon steel plate.

Therefore, when coiling a large number of high-tensile steel plates, it is necessary to change the conditions between the coils and the coils, or to work the low-carbon steel plates under the same conditions as the high-tensile steel plates. In the former case,
This results in a decrease in work efficiency, and it is impossible to strictly adhere to the working conditions. In the latter case, the quality of low carbon steel will deteriorate.

(c) Problem to be solved by the invention The problem to be solved by the invention is to develop a high-strength thin steel plate that can connect high-strength thin steel plates to each other without impairing weldability in a process line for thin steel plates. It's all about finding a way to connect.

B) Means for Solving the Problems The method for connecting high-tensile steel sheets of the present invention involves sandwiching a low-carbon thin steel sheet of a predetermined width between the ends of the thin steel sheets in a process line for high-strength thin steel sheets. The above-mentioned problem is solved by overlapping them and applying resistance welding to the overlapping portions.

(e) Examples FIG. 1 shows a method of connecting high-strength thin steel plates 1 of the present invention.

In a process line for high-tensile steel sheets, the ends of produced high-tensile steel sheets 1 (hereinafter simply referred to as steel sheets) are cut and sent.

The ends of each steel plate 1 as a leading member and a trailing member are overlapped with each other. At this time, a low carbon steel plate 2 of a predetermined width is sandwiched between the ends of the steel plates.

Next, resistance welding is performed in the width direction of the plate using the contact electrode roll 3 of the welding machine.

In the method of the present invention, the thickness of the thin steel plates to be connected is 0.2 to 3,
The thickness of the low carbon steel plate 2 used therein is about 0.05 to 0.3 mm.The carbon content of the low carbon steel plate 2 is 0.002 to 0.08 mm.
tlb is preferred. If it is less than 0.002%, it is difficult to manufacture. If it is more than 0.08%, weldability deteriorates.

The thickness of the low carbon steel plate 2 is preferably 0.05 to 0.3 fi.If it is less than 00.05 m, the effect will be small. If it exceeds 013n, workability will deteriorate.

(F) Specific Examples Table 1 shows the implementation results of the method of the present invention in comparison with the conventional method.

[Brief explanation of drawings]

Figure 1 is an outline of the method of the present invention, explanatory diagram 01: High tensile strength thin steel plate 2: Low carbon steel plate 3: Contact electrode roll Patent applicant Sumitomo Metal Industries, Ltd. (5 others)

Claims (1)

[Claims] In a high-tensile thin steel plate process line, a low-carbon thin steel plate of a predetermined width is sandwiched between the ends of the high-tensile thin steel plate and overlaid, and the overlapping portion is resistance welded. How to connect steel plates.