A kind of high-strength spot welding strap and its production method

Abstract

The invention discloses a high-strength spot welding strapping band which comprises the following components in percent by weight: 0.15-0.24 percent by weight of C, 0.7-1.30 percent by weight of Mn, less than 0.010 percent by weight of Si, less than or equal to 0.010 percent by weight of P, less than or equal to 0.010 percent by weight of S, 0.020-0.050 percent by weight of V and 0.030-0.070 percent by weight of Als. A production method comprises the steps: smelting and continuously casting to form a blank, and heating a casting blank; roughly rolling; finish-rolling; coiling; conventionally pickling; cold-rolling; and making the strapping band. The thickness of the high-strength spot welding strapping band is 0.70 mm, the tensile strength of the high-strength spot welding strapping band is not lower than 980 MPa, the percentage elongation is not lower than 10 percent, the number of alternating bending is not less than 10 times (R=5 mm), and no brittle failure and layering exist; an Fe3O4 bluing layer with a thickness of 0.3-0.5 mu m, and uniformity and densification and strong adhesive force is formed on the surface. No cracks exist on a weld line, and a welding point is stable in surface quality and better in welding property; no remarkable corrosion is caused in an indoor atmospheric environment for 30 days; no blockage, breakage and coil loosening are caused during packing.

Description

technical field [0001] The invention relates to a strap and its production method, in particular to a high-strength spot-welded strap for high-temperature coiling of heavy hot-rolled coils and section steel and a production method thereof, and is especially suitable for heavy-duty heavy coils High temperature coiling of rolled plate coils and sections. Background technique [0002] High-strength spot-welded strapping is a cold-rolled deep-processing product with broad market prospects. It is widely used in high-speed automatic strapping machines for bundling and packaging steel coils to ensure continuous production and improve work efficiency. [0003] At room temperature, when steel coils are bundled, two methods of manual bundling or automatic bundling can generally be used. In case of loose coils, manual remedies can also be carried out. However, during high-temperature coiling, in order to ensure the safety of operators and prevent scalds and burns, the machine can only...

AI Technical Summary

Problems solved by technology

Although the use of water as the quenching medium makes the pollution less, but due to the strong cooling capacity, the internal stress of the steel plate is relatively large, the product is prone to cracking, and the product cannot be guaranteed to have a good shape.

In addition, the raw steel contains high content of Si, P and S, which leads to poor surface quality of the product, poor toughness and weldability, and brittle fracture easily

Images