JPH01170596A - Heat treatment of after non-consumable electrode type gas shielded arc welding - Google Patents

Abstract

PURPOSE:To improve the bending characteristic of a weld zone by executing a rapid heating and rapid cooling heat treatment of a weld zone at the heat input amt. smaller than that of the initial welding time in case of making in longer size by executing the gas shielded arc welding using non-consumable electrode of the end part of a plate like bar stock. CONSTITUTION:A rapid heating and rapid cooling heat treatment is executed on a weld zone at the quantity of heat of 0.3-0.6 times the heat input ant. of an initial welding time, in case of longsizing the end part of the plate like bar stock rolled in the specified plate thickness by executing gas shielded are welding using non-consumable electrode. By this method the bending characteristic of the weld zone is improved and in case of punching the dimensional accuracy is improved and the yield is improved as well.

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention is a method for improving the bending properties of welded parts by non-electrode gas-shielded arc welding of copper alloys, which are widely used as electronic components such as terminals and connectors. be.

[Prior Art] Copper alloys have excellent mechanical strength and electrical conductivity, and are therefore widely used in electronic components such as terminals and connectors. When processing copper alloy parts, strips are used and are punched out using a continuous press machine either as they are or after surface treatment such as tin plating. It is desired to reduce the amount of waste and improve equipment efficiency, and the length of strips is being increased. In order to make the strips longer, there are ways to make the strips themselves larger, or to join two or more strips by welding, which eliminates the need for large-scale capital investment and allows for arbitrary lengths. , a method has been adopted in which the strips are made longer by welding.

Gas-shielded arc welding is widely used for welding copper alloys, and this is an arc welding method in which the arc-welded metal and welding area are shielded from the atmosphere with a specific gas. Non-electrode arc welding, which uses materials that are not consumed by welding, is suitable for welding strips because it does not require flux and can be applied to welding from extremely thin plates 6 to thick plates.

[Problems to be Solved by the Invention] In the above-mentioned conventional technology, when a strip is punched using a continuous press machine, the thickness of the weld bead is raised and thicker than the thickness of the material. Therefore, the welded part is rolled to the thickness of the material. Because the weld is work-hardened by rolling, the strength of the weld bead is high (but conversely, the elongation and bending properties are reduced, and if strong bending stress is applied during punching with a continuous press, the weld may break. Fractures occur and damage the press die.Therefore, a method of improving the bending properties of the weld is desired.

The present invention has been made in view of the above circumstances, and an object of the present invention is to improve the bending characteristics of a welded part.

[Means for Solving the Problems] The present invention involves the initial welding of a copper alloy by non-electrode gas-shielded arc welding using a non-electrode gas-shielded arc welding machine after rolling it to the thickness of the material. This is a heat treatment method after non-electrode gas-shielded arc welding, which is characterized by rapid heating and rapid cooling heat treatment with a heat amount of 0.3 times or more and 0.6 times or less of the welder's heat.

The reason why the heat treatment equipment is limited to non-electrode type gas shielded arc welding machines is that only the welded part can be easily heat treated.

In the present invention, the heat treatment temperature is set to 0.3 of the initial welding temperature.
The reason why it is limited to more than 0.6 times and less than 0.6 times is that if it is less than 0.3 times, the welded part will not be sufficiently softened and the sufficient effect will not be obtained, and if it exceeds 0.6 times, the welded part will re-melt. For,
This is because strong rolling must be performed again, and there is a risk that the bending properties will be lower than before the heat treatment. Moreover, this heat treatment must be performed by rapid heating. Incidentally, after rolling the welded part, heat treatment using a burner etc. may be considered, but if only a narrow area of the welded part is not heated, the yield will not only decrease, but also the material that has undergone surface treatment such as plating will This is not a sufficient countermeasure because tin, which has a low melting point, remelts and causes variations in plating thickness. For this purpose, it is necessary to locally perform rapid heating and cooling heat treatment using a welding machine.

[Example] Examples of the present invention will now be described.

The sample material is 7.9% tin, 0.15% phosphorus, the balance is copper and unavoidable impurities, thickness 0.2ma+, width 100mm.
phosphor bronze strip (phosphor bronze material) and an additional thickness of 1 μm
A tin-plated strip (phosphor bronze plated material) was used.

The test material was cut with a shear, welded under the conditions shown in Table 1, rolled to the thickness of the material, heat treated with the prescribed heat input also shown in Table 1, and then subjected to a 90° repeated bending test. The repeated bending characteristics of the welded part were evaluated. In arc welding, the thermal energy of the arc, that is, the heat input, is approximately expressed as the electrical energy generated by the arc per unit length of the bead, and is given by the following equation.

H-60El/V where H: Heat input per unit length of bead (J/m) E: Arc voltage (V) Work: Welding current (A) v Welding speed (II+/+11111) Results of the above test, When processed using a welding machine under specified conditions, the bending properties are improved, and even when processed using an actual continuous press machine, bending and breakage do not occur, making it possible to significantly improve equipment efficiency. Ta.

[Effects of the Invention] According to the present invention, the bending properties of a welded portion of a copper alloy by non-electrode gas shield welding are improved, and punching as an electronic component can be performed with a higher yield.

Claims (1)

[Claims] After rolling the welded part of copper alloy by non-molten gas shielded arc welding to the thickness of the material, use a non-molten gas shielded arc welding machine to heat the welding area by 0.3 times or more and 0.6 times or less of the initial welding heat. A heat treatment method after non-liquid gas shielded arc welding, which is characterized by rapid heating and rapid cooling heat treatment with a heat amount of .