1、 FORD LABORATORY TEST METHOD BA 013-03 Date Action Revisions 2001 03 02 Revised Editorial no technical change A. Cockman 2000 05 22 Editorial no technical change A. Cockman 1992 07 24 Printed copies are uncontrolled Page 1 of 6 Copyright 2001, Ford Global Technologies, Inc. WELDING ACCEPTANCE TEST F
2、OR ZINCROMETAL Application This procedure is a standard welding acceptance test for one-side coated zincrometal. Equipment 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
3、 Resistance Welders Manufacturing Association specifications for the size of machine required. It shall be equipped with a Ford approved resistance welding control featuring 90 firing and phase shift heat control. It shall have electrode force capacities to meet the requirements of the range of mate
4、rial to be tested at 550 kPa line pressure. The transformer shall be selected to meet the secondary current requirements at phase heat control settings between 85 and 100 %. The welder must be equipped with electrode holders conforming to Ford Drawing 2 ZU 265 and shall have furnished to it sufficie
5、nt water flow capacity so that two gallons per minute will flow through each electrode holder as isolated circuits from the water cooled transformer, secondary conductors, control panel, etc. Coating Thickness Tester Permascope - General Electric Model ES2J40A or equivalent. Instrumentation For the
6、current break through test - a galvanometer-type oscillograph shall be used for recording the sine wave of the secondary current. Welding Electrodes 3/4“ Ford standard design electrode caps will be used for all tests. The applicable design will be selected from Ford standard electrode cap specificat
7、ion sheet WC 1-1, Page 1. They will be manufactured from material complying with Ford Standard M1566-B, which is an RWMA Class II material. Exception to this specification will be that the minimum hardness on the welding face shall be Rockwell B 78. The electrode caps, adapters and holder to be used
8、 will be found under the following identifications: Electrode Caps WC 1A26A; WC 1A26B; WC 1A26C (select for steel thickness) Cap Adapter WB 1S Electrode Holder Assembly - Drawing 2 ZU 265. (WH103-3C) FORD LABORATORY TEST METHOD BA 013-03 Page 2 of 6 Copyright 2001, Ford Global Technologies, Inc. Con
9、ditioning and Test Conditions All test values indicated herein are based on material conditioned in a controlled atmosphere of 23 +/- 2 C and 50 +/- 5 % relative humidity for not less than 24 h prior to testing and tested under the same conditions unless otherwise specified. Procedure Preparation of
10、 Material The material for spot weld qualification shall be representative of production practices in the ordered minimum thickness. Submission shall be in full width sheets of at least 36 inches wide. The material under test shall be supplied in full coil width. The material shall be sheared in 4 x
11、 12 inch pieces across the full trimmed width. From selected representative pieces, a number of inch x 4 inch coupons will be prepared from a material under test which are free from burrs. Care shall be exercised so as not to remove any oils used for corrosion or shipping protection. Coating thickne
12、ss on these panels shall be measured and recorded. Coating thickness shall be 0.0005 - 0.0008 inch. Current Break Through Test 1. Prepare 50 test coupons, 1 x 3 inch by metal thickness, the test coating applied on one side of each coupon. 2. Assemble 25 weld coupons by placing two coupons face-to-fa
13、ce with their coated sides outward and successively weld each assembly as specified. 3. Examine the secondary current trace of each weld for length of time in half cycles that is required to reach 90 % of full welding current at the weld schedule shown in Table 1. The zincrometal coating under these
14、 conditions shall require no more than two half cycles to reach 90 % of full welding current on all 25 welded coupons. 4. Repeat test with the coated sides face-to-face and the electrodes contacting the bare steel. 5. Break Through Tests also shall be conducted throughout the 2,000 spot weld test as
15、 described under this procedure. FORD LABORATORY TEST METHOD BA 013-03 Page 3 of 6 Copyright 2001, Ford Global Technologies, Inc. 2,000 Spot Weld Acceptance Test Coupon Size Specimens for this setup are 4 x 12 inch coupons of the actual test material. The coated sides shall be aligned to contact bot
16、h electrodes. Setting and Establishing Button Size Using 1 x 4 inch test coupons and the weld schedule shown in Table 1, two welds will be placed on their center line approximately 2 inches apart. Weld current shall be increased until the weld button diameter or metal expulsion occurs on the second
17、weld. It is expected that this condition shall be achieved in less than 25 welds and the welds made on the caps to date will not constitute part of the 2,000 spot weld test count. The diameter of the weld button as determined by the method described under “Determination of Spot Weld Diameter“ shall
18、be recorded on the Companys 2,000 spot weld acceptance data sheet. Also recorded at this time will be a secondary current value as measured by a Duffers secondary current meter, weld time, electrode force, primary voltage. Electrode Initial Button Diameter Minimum Button Configuration (In.) + .01 -
19、.00 Diameter (In.) .31“ x 30 .31 .28 .25“ x 45 .25 .22 .19“ x 45 .19 .16 After establishing the proper weld button diameter, 2000 spot welds using the 4 x 12 inch sheets of test material sheared across the width of the sheet, either transverse or longitudinal, shall be made without attention to the
20、electrodes or adjustment of the weld schedule. If during the initial 50 welds of this test, metal expulsion occurs, the secondary current may be reduced slightly but not more than 3 % until the expulsion disappears. However, it should be brought back to its original value as soon as possible. The fo
21、llowing procedure details shall be followed during this test: (a) Rate of welding is the responsibility of the vendor but shall be at a minimum rate of 20 spot welds per minute. (b) To avoid welding on overheated panels, the panel shall be set aside and allowed to cool. Welding will be continued on
22、a second set of panels. Additional welds may be made on the panel after cooling. FORD LABORATORY TEST METHOD BA 013-03 Page 4 of 6 Copyright 2001, Ford Global Technologies, Inc. (c) After every 250 welds, repeat the determination of button diameter through the use of 1 x 4 inch coupons as described
23、below. Under no circumstances shall the current level be raised above the established to provide initial spot welded button diameter. (d) Make two welds on this 1 x 4 inch test coupon and observe the break through test condition on both welds. Peel the second for determination of button size. If bot
24、h welds comply with break through and button size requirements, then proceed to make the next 250 consecutive welds on the large 4 x 12 inch panels. (e) The above steps shall be repeated until 2,000 spot welds are obtained or the weld button or break through on a coupon is below the minimum specifie
25、d. When the first substandard button size or break through failure is encountered, five additional test coupons shall be made consecutively and measured. Failure shall be firmly established whenever the weld nuggets or break through of any two of the additional five coupons measure below the specifi
26、ed minimum diameter or whenever any one of the coupons produces no welds. This latter situation is cause for failure even though the remaining four coupons show acceptable nugget sizes and break through characteristics. The above procedure of five additional weld coupons shall also be made at the 2,
27、000 spot weld level even though no substandard conditions have been encountered at that point. Determination of Spot Weld Diameter 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 s
28、hall be measured through their narrowest section when irregular shaped or through the minor diameter when elliptical in shape (see illustration following). FORD LABORATORY TEST METHOD BA 013-03 Page 5 of 6 Copyright 2001, Ford Global Technologies, Inc. Use knife edge dial caliper (Mitotoyo Model 505
29、629 or equivalent) to measure button size. Weld Schedule Ordered Minimum Formerly Electrode Weld *Secondary Electrode Metal Specified Force Time Current Face Thick. (In) Thick. (In) (Lbs.) Cycles Amperes Configuration .082 (.090) 1300 24 20,000 .31“ Face x 30 .068 (.075) 1050 20 19,000 .31“ Face x 3
30、0 .054 (.060) 850 13 16,250 .25“ Face x 45 .043 (.048) 725 13 15,000 .25“ Face x 45 .036 (.041) 650 13 14,000 .25“ Face x 45 .031 (.035) 450 10 12,500 .19“ Face x 45 .028 (.032) 450 10 11,500 .19“ Face x 45 .026 (.030) 400 10 10,500 .19“ Face x 45 * Values are approximate and are intended as a guide
31、 to specify capacity of welding machines and initial setup. Actual current value for a particular test specimen is established by following test procedure outlined in paragraph describing “Setting and Establishing Button Size“. FORD LABORATORY TEST METHOD BA 013-03 Page 6 of 6 Copyright 2001, Ford G
32、lobal Technologies, Inc. Porosity Test in Weld Nugget This test is intended to evaluate the undesirable characteristics generated by zincrometal by forming porosity in the weld nugget, particularly on the thinner gage metal .043 minimum and thinner. It is the intent of this test to determine the qua
33、lity of the zincrometal coating, which when properly formulated will allow no pinhole generation on the heavy steels and on the thinner materials within the first 1250 consecutive welds. The formulation will be determined acceptable if no pinholes are generated in any of the first 1250 welds, and th
34、at there will be no more than 50 spotwelds containing pinholes thereafter to the 2000 spotweld level. There shall be no pinhole porosity generated in any of the test specimen in thicknesses above .043 minimum. Evaluation of the nuggets porosity will be made on each weld executed in the 2000 spotweld
35、 test, including those made for peel tests. Pinhole porosity will be ascertained by visual inspection. The porosity as herein defined is that porosity which results in pinholes protruding completely through the weld nugget, no matter how small or large in diameter. 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.
