TH2001004414A - Resistance spot welding methods and methods for the manufacture of resistance spot welding joints - Google Patents

Abstract

DEPCT64 The invention will provide a resistance spot welding method. spot welding method with resistance according to the fabrication where the joining of sheets of metal sheets is overlaid. Two or more pads are sandwiched between a pair of electrodes and held together by Current applied while pressurized, a method that includes a primary current procedure in which current application is Conducted with current Iw (kVA) and after that, heat treated with After tempering where, after cooling is performed for the cooling time tct (ms) shown in formula (1) below, the application current is performed with the It (kilogram) current. amperes) shown in formula (2) below for the current consumption time tt (ms) shown in formula (3) below, where at least one steel plate in the plate joint assembly There will be elements containing: 0.08 less than or equal to C, less than or equal to 0.3 (mass percent), 0.1 less than or equal to Si, less than or equal to 0.8 (mass percent), 2.5 less than or equal to Mn, less than or equal 10.0 (mass percent) and P less than or equal to 0.1 (mass percent) with equilibrium Fe and inevitable impurities: 800 less than or equal to tc1 Formula (1) , 0.5 X Iw less than or equal It less than or equal to Iw ••• Formula (2) and 500 less than or equal to tt ••• Formula (3) --------------- --------------------------------------------

Claims (4)

DEPCT64 1. Resistance spot welding method in which the joining of sheets of sheet metal Two or more overlapping pads are sandwiched between a pair of electrodes and bonded. together by applying current while applying pressure, which methods include: Primary current application process in which current application is carried out with current Iw (kVA); and thereafter, a post-tempering heat treatment procedure in which, after The cooling is performed for the cooling time tct (ms) shown in Formula (1) below, the current consumption is performed with the It current (kiloamperes) shown in Formula (2). ) below for the current consumption time tt (ms) shown in formula (3) below, where at least one steel plate in the plate joint assembly will have Available elements: 0.08 less than or equal to C, less than or equal to 0.3 (mass percent), 0.1 less than or equal to Si, less than or equal to 0.8 (mass percent), 2.5 less than or equal to Mn, less than or equal to 10.0 ( mass percent) and P less than or equal to 0.1 (mass percent) together with the equilibrium Fe and inevitable impurities: 800 less than or equal to tct Formula (1), 0.5 x is less than or equal to Iw is less than or equal to It is less than or equal to Iw Formula (2), and 500 is less than or equal to tt Formula (3) 2. Method of resistance spot welding according to Claim 1, incorporating, between the main current procedure and the subsequent tempering heat treatment procedure: by heating by reducing the dissociation after which, after cooling is performed for the cooling time tcp (ms) shown in Formula (4) below, using current Ip (kiloamperes) is performed as shown in Formula (5) below. For current consumption time tp (ms) shown in formula (6) below: 10 less than or equal to tcp Formula (4), 0.6 x Iw less than or equal to Ip less than or equal to 0.99 x Iw ••• Formula (5), and 400 less than or equal to tp ••• Formula (6) 3. Method of resistance spot welding according to Claim 1 or 2, where the steel plate At least one plate in a plate joint assembly shall have a tensile strength of 780 MPa or more. 4. Methods for the manufacture of resistance spot welded joints. by using welding method Dot type with resistance according to either claim 1 or 3 ----------------------------- ------------------------------