1、 FORD LABORATORY TEST METHOD BA 113-01 Date Action Revisions 2001 03 02 Revised Editorial no technical change A. Cockman 1991 02 22 Printed copies are uncontrolled Page 1 of 5 Copyright 2001, Ford Global Technologies, Inc. SPOT WELDING ACCEPTANCE TEST FOR ZINC, ZINC/IRON AND ZINC/ALLOY COATED LOW CA
2、RBON STEEL SHEET Application This procedure defines the welding acceptance test for zinc, zinc/iron and zinc/alloy coated low carbon steel sheet. All such steels must pass a minimum of 2000 welds. Some may require a higher number of welds to failure. Consult the appropriate Engineering Material Spec
3、ification for exceptions. Apparatus Required Spot Welder This test shall be conducted on an air-operated single point press-type spot welder featuring a low inertia welding system and, in general, complying with the Resistance Welders Manufacturing Association specifications for the size of machine
4、required. It shall be equipped with a Ford-approved resistance welding control featuring 90 firing and delayed conduction heat control. It shall have electrode force capacities to meet the requirement of the range of material to be tested at 550 kPa line pressure. The transformer shall be selected t
5、o meet the secondary current requirements at heat control settings between 75 % and 100 %. The welder must be equipped with electrode holders conforming to Ford Manufacturing Standard WH 1032C or WH 1033C and shall have furnished to it sufficient water flow capacity so that 7.6 litres per minute wil
6、l flow through each electrode holder as isolated circuits from the water-cooled transformer, secondary conductors, control panel, etc. Coating Thickness Shall be determined by strip weight method or suitable testing instrument. Dial Caliper - Brown WC1-1A26B; WC1-1AA26C, WC1-1AA27D (select for steel
7、 thickness). . Cap Adapter WB1-S35, WB1-1S36, or WB1-1S37 (code for desired length). . Electrode Holder Assembly - Manufacturing Standard WH 1032C or WH 1033 C. Duffers Secondary Current Meter . Model 8120 or equivalent. Procedure Preparation of Material The material for spot weld qualification shal
8、l be representative of production practices in the ordered minimum thickness. Submission shall be in full-width sheets of at least 915 mm in width. The galvanized material under test shall be supplied in full coil width. 100 mm shall be trimmed from each edge and scrapped. The material shall be shea
9、red in 100 x 300 mm pieces across the full trimmed width. From selected representative pieces, a number of 30 x 100 mm coupons which are free from burrs will be prepared from the material under test. Care shall be exercised so as not to remove any oils used for corrosion or shipping protection. Coat
10、ed Galvanized Coating thickness on each side of 100 x 300 mm panels shall be measured and the heavier coated side shall always be against the electrodes. 2,000 Spot Weld Acceptance Test Electrode Alignment and Conditioning The electrode caps shall be installed in the machine in precise vertical alig
11、nment and with faces parallel when subjected to the electrode force requirement for the material under test. Tip faces may be dressed to parallel by rotating a sheet of emery paper (folded over a single weld coupon) between the tips, at low tip dressing force. Alignment is to be checked by welding o
12、n a single coupon of uncoated steel (at low current and 2 - 5 cycles weld time) to assure uniformity of the heat pattern. Caps are to be conditioned by making a series of 25 welds, at welding currents just below expulsion on 100 x 300 mm panels of the actual test material. Use the proper schedule li
13、sted in Table I for making these conditioning welds. FORD LABORATORY TEST METHOD BA 113-01 Page 3 of 5 Copyright 2001, Ford Global Technologies, Inc. Setting and Establishing Button Size Using 30 x 100 mm test coupons and the weld schedule shown in Table I, two welds will be placed on their center l
14、ine approximately 50 mm apart. Weld current shall be adjusted until the weld button diameter on the second weld equals or exceeds the electrode cap face diameter without metal expulsion occurring on the second weld. If this condition cannot be achieved, then set current to be just below expulsion an
15、d use this current for testing. Make ten samples at this heat setting. All ten button diameter sizes must be above minimum. If they are not, the material is a failure. It is expected that this brief set-up procedure shall be completed in less than forty welds. The welds made on the caps to this poin
16、t will not constitute part of the 2,000 spot weld test count. The diameter of the ten weld buttons as determined by the method shown elsewhere in this test method shall be recorded. Record the set-up welding current as measured by a Duffers secondary current meter, weld time, electrode force, and pr
17、imary voltage. Electrode Initial Button Diameter Minimum Button Face Diameter mm + 0.25 - 0.00 Diameter (mm) 7.9 mm 7.9 7.1 6.4 mm 6.4 5.6 4.6 mm 4.6 3.8 Testing will be conducted without changes to equipment settings or electrode dressing. During initial stages of testing, occurrances of expulsion
18、will be noted with no adjustment to secondary current (heat setting). The following additional procedure details shall be followed during testing: . Rate of welding shall be at a minimum rate of 20 spot welds per minute. . To avoid heat build-up, welding may be alternated between test panels. . Afte
19、r every 250 welds, repeat the determination of button diameter through the use of 30 x 100 mm coupons as described below. Under no circumstances shall the current level be raised above that established to provide initial spot welded button diameter. . The above steps shall be repeated until 2,000 sp
20、ot welds are obtained or the weld buttons are below the minimum specified. Failure shall be firmly established whenever the weld nuggets of any two of the five coupons measure below the specified minimum diameter or whenever any one of the coupons produces a “no weld“. This latter situation is cause
21、 for failure even though the remaining four coupons show acceptable nugget sizes. Failure, other than a no weld, must be obtained on two consecutive checks, 250 welds apart. FORD LABORATORY TEST METHOD BA 113-01 Page 4 of 5 Copyright 2001, Ford Global Technologies, Inc. Determination of Spot Weld Di
22、ameter The spot weld specimen must be made so as to permit the weld button to be peeled perpendicular to the narrowest section. The buttons pulled from the spot weld specimen shall be measured with a dial caliper, through their narrowest section when irregularly shaped or through the minor diameter
23、when elliptical in shape (see illustration following). Chemicals, materials, parts, and equipment referenced in this document must be used and handled properly. Each party is responsible for determining proper use and handling in its facilities. FORD LABORATORY TEST METHOD BA 113-01 Page 5 of 5 Copy
24、right 2001, Ford Global Technologies, Inc. WELDING ACCEPTANCE TEST FOR GALVANIZED LOW CARBON STEEL TABLE I TEST SCHEDULE Actual Metal Electrode Thickness Face Dia. Force * Weld Time Weld Current Mm (in) mm (in) KN (lbs) Cycles (ka) 0.51 (.020) 4.6 (.19) 1.3 (300) 8 8.25 0.61 (.024) 4.6 (.19) 1.6 (35
25、0) 9 9.5 0.66 (.026) 4.6 (.19) 1.8 (400) 10 10.5 0.71 (.028) 4.6 (.19) 2.0 (450) 10 11.5 0.78 (.031) 6.4 (.25) 2.2 (500) 12 13.5 0.91 (.036) 6.4 (.25) 2.9 (650) 13 14.0 1.09 (.043) 6.4 (.25) 3.2 (725) 13 15.0 1.37 (.054) 6.4 (.25) 3.8 (850) 15 16.3 1.72 (.068) 7.9 (.31) 4.7 (1050) 20 19.0 2.08 (.082
26、) 7.9 (.31) 5.8 (1300) 24 20.0 2.43 (.096) 7.9 (.31) 7.3 (1650) 30 22.0 2.78 (.110) 7.9 (.31) 8.0 (1800) 34 24.0 * FORCE AND TIME VALUES MAY BE INTERPOLATED FOR INTERMEDIATE THICKNESS Listed welding current values are typical and are to be used only as a first approximation in the set-up procedure. Electrode diameters change size at midpoint of listed thickness values, i.e.: 0.84 use 4.6 face diameter 0.86 use 6.4 face diameter Note: The values shown in Table I are intended for use in approving suppliers and are not intended for production use.
