奔驰车身点焊标准_图文

1、Mercedes-Benz MBN 10 382Engineering Standard Date Published: 2005-05Category: 37 Total No. of Pages (Including Annex: 20Person in Charge: Michael RutherPlant 050; Dept.: PWT/VFTDate of Translation: 2005-08 Phone:+49(07031-90-79302Resistance Spot Welding of Steel,Thickness up to 3 mmWiderstandspunkts

2、chweißen von Stahl bis 3 mmForewordDue to more complex requirements resulting from the increased use of high-strength and ultra high-strength steels, resistance spot welding is subject to continuous adaptation. This Standard super-sedes the previous Mercedes-Benz spot welding standard F0 930500

3、55317.ChangesIn comparison with F0 93050055317 edition 2000-05, the following changes have been made:Extension of material spectrum (high-strength and ultra high-strength steelsSuitable welding parameters for high-strength and ultra high-strength steelsIntroduction of weld spot classesDesign of weld

4、ing gun, transformer, welding control system, peripherals Reworking conceptNOTE: No guarantee can be given in respect of this translation. In all cases the latestGerman-language version of this Standard shall be taken as authoritative.Copyright DaimlerChrysler 2005Contents 1Scope.2 2Normative Refere

5、nces.3 3Abbreviations, Acronyms, Definitions, & Symbols.3 4Regulated Substances and Recyclability.4 5General.4 5.1Design of Welding Gun.4 5.2Design of Control System and Transformer.4 5.3Design of Process.45.4Design of Peripherals.46Weld Spot Classes.5 6.1Definitions.5 6.2Definition of Special S

6、pots.5 6.3Criteria for Special Spots.56.4Special Measures Required for Special Spots.57Welding Parameters for 2-Sheet Welds.6 7.1Standard Value Table.6 7.2Electrode Force.6 7.3Welding Current.7 7.4Welding Time.7 7.5Squeeze Time.7 7.6Hold Interval.7 7.7Preheating.77.8Standard Values for 2-Sheet Welds

7、.883-Sheet and 4-Sheet Welds.10 8.1General. 10 8.2Sheet Arrangements.10 8.3Welding Parameters.11 8.4Electrodes. 128.5Nugget and Spot Diameters for 3-Sheet Welds.129Minimum Flange Widths.13 9.1Minimum Flange Widths for 2-Sheet Welds.13 9.2Minimum Flange Width for 3-Sheet Weld.15 10Weld-Bonding. 15 11

8、Minimum Requirement for Spot Weld Joint.15 11.1Spot Diameter.15 11.2Nugget Diameter.16 11.3Minimum Edge Distance of the Weld Spot.16 11.4Position Tolerance of the Weld Spot.16 11.5Surface Quality.16 12Assurance of the Weld Spot Quality.16 13Reworking of Weld Spots which Do not Fulfill Minimum Requir

9、ements.16 13.1Fundamental Rework Processes. 17 14High-Strength and Ultra High-Strength Steels.18 14.1Welding Parameters.18 14.2Testing. 19 1 ScopeThis Standard applies to all resistance spot-welded joints used in the body shell shop at DaimlerChrysler. During prototype production, the weld spots are

10、 applied with manually operated spot welding guns, while in volume production both robot spot welding guns and manually operated spot welding guns are used with welding control systems and other contributing units.The relevant departments are responsible for implementing this Standard.2 Normative Re

11、ferencesF0 05080 055466 Strukturelles Kleben im Karosserierohbau (Structural bonding in the body shell shop DVS 2916 Prüfen von Punktschweißverbindungen (Testing of spot-welded jointsDVS 2902-4 Widerstandspunktschweißen von Stählen bis 3 mm EinzeldickeDC Schweißzangenrichtli

12、nien (Resistance spot welding of steel; individual thick-ness up to 3 mm; DC welding gun guidelines3 Abbreviations, Acronyms, Definitions, & Symbolsd L :Nugget diameterd P :Spot diameterd P min :Required minimum spot diameterd L min :Required minimum nugget diametere E :Depth of electrode indent

13、ationF E : ElectrodeforceHV: VickershardnessI S : WeldingcurrentNHZ: Hold intervalNWZ: Postheating timePSK: Weld-bondingR e : YieldstrengthR m : Tensilestrengtht: Sheetthicknesst G : Total sheet thicknesst min :Minimum (relevant sheet thickness of a welding taskt S : Weldingtimet V :Reference sheet

14、thicknessVHZ: Squeeze timeVWZ: Preheating timeWEZ:Heat affected zone (HAZ4 Regulated Substances and RecyclabilityAll materials, methods, processes, components and systems shall conform to the applicable statutory regulations with regard to controlled substances and recyclability.5 GeneralThe require

15、ments of the core standard (internal DC welding gun guideline shall be fulfilled in the layout and design of the welding guns and peripherals.5.1 Design of Welding GunIn the design of the power generation systems and the welding gun care shall be taken to ensure that the required electrode force can

16、 be significantly increased by means of force allowances (material, surface treatment, fit on the base values.Electrode forces above 5000 N shall be agreed with the responsible DC department.5.2 Design of Control System and TransformerGiven the large variety of coatings and materials and the related

17、 requirements for the resistance spot welding technology, medium-frequency technology shall be used in principle for all future model se-ries.Sufficient cooling of electrodes (at least 2 l/min per electrode and transformers, in particular of MF transformers, shall be ensured (observe manufacturers i

18、nstructions. The flow rate is more significant than the inlet temperature which should not exceed 30 °C.In the design of the welding transformers, sufficient reserve for the stepper function shall be provided (Itarget + 30%. At the end of the stepper, the transformer shall operate at no more th

19、an 70% output (phase angle. For the design of the transformers, the smaller current value from Table 1 shall be used.Welding current transformers shall be provided with fault current monitoring as secondary circuit moni-toring. Grounding on the secondary side is not permitted as a protective measure

20、.5.3 Design of ProcessWhere bonding or sealing materials are used on one or two joining levels, the squeeze or welding time must usually be extended depending on the task in hand.Electrode cap geometries deviating from F and A shall always be subject to the approval of EP and PWT/VFT.5.4 Design of P

21、eripheralsFor surface-treated sheets (zinc-coated or organically coated, electrode cap cutters shall be provided if one or two electrodes bear against the coating.In the case of multiple spot welding units and equipment, the copper back-up bars shall be insulated, if required also against each other

22、. The insulation should be as close as possible to the welding spot. Holders, guides and hold-down devices shall not lie on the same potential as the copper back-up bar or electrode.Copper back-up bars bearing against an organic coating are not permitted.In the case of shunt problems caused by nonco

23、nductive or not very conductive layers (e.g. adhe-sives, holders, tools and clamps shall be insulated.6 Weld Spot Classes6.1 DefinitionsFailure may result in damage which may impair overall safety. Special spots shall be marked “SP” on the design drawing. These spots require an increased production

24、and test input (Section 6.4. For SPs, the minimum requirement min 5, 3d L = or min 4t d P = applies. Weld spots required for a continuous production sequence and process. The component function re-mains unimpaired even without these spots. Production spots shall be marked “FP” on the design drawing.

25、FPs have to comply with the requirement min 5, 3t d L = or min 4t d P =. Failure does not impair or only insignificantly impairs the overall function of the vehicle. For NPs, the minimum requirement min 5, 3d L = or min 4d P = applies. All weld spots which are neither SP or FP are standard spots. Th

26、ey are not specifically identified onthe drawing.In addition, the totality of the weld spots can be broken down into two groups from the point of view of the production sequence: Geometry spots which are placed within the positioning device (e.g. Geostation. Finish-weld spots which are placed in dow

27、nstream finish-weld lines.The previously used terms Control Spot (KP and Tacked Spot (HP are omitted and shall no longer be used in the planning of new model series.6.2 Definition of Special SpotsDesign is responsible for the definition process for SPs.6.3 Criteria for Special SpotsSpecial Spots are

28、 defined to assure the safety-critical function of a joint created using the resistance spot welding process. For each safety-critical joint, at least two special spots are required. Criteria for the iden-tification of safety-critical joints include, for example: Experiences from predecessor type or

29、 reference type Connection to seats, restraint systems, axles Innovations Results from durability tests Results from crash tests Results from vehicle observations on the road (market observation6.4 Special Measures Required for Special SpotsThe following applies in addition to Special Spots:Design:

30、Special spots are marked “SP“ on the design drawing. Two-sided, single-cut spot welding (direct welding only is permitted. 3-sheet welding can only be per-mitted in exceptional cases, i.e. following relevant assurance by PWT/VFT. Multi-spot welds are not permitted.Process: The power generation syste

31、ms and the welding parameters shall be selected according to Table 1.Peripherals: Use of electrode cutters is obligatory for all welds using robots. For machine welding equipment onlyfollowing agreement with DaimlerChrysler. Minimum requirement is the use of control systems with constant current sta

32、bilizers. Alternatively,control systems or equipment with identical or higher process reliability may be used. In the case of defects (e.g. welding current too low/high, no step enable contact shall be triggered in the weld con-trol system, i.e. the welding equipment shall stop. The system operator

33、shall be informed of the defect in a suitable manner. Special weld spots at a safety-critical joint shall be divided within the production cell among at leasttwo welding devices operating independently of each other. The number of special spots to be welded by each welding device shall not differ by

34、 more than one weld spot in this process. If an identical or higher process reliability can be achieved by using alternative solutions (e.g. systemsfor inline process monitoring and/or control as opposed to the division of weld spots, the division of the weld spots to several welding devices can be

35、dispensed with. In machine welding equipment, the welding transformers for the special spots shall be controlled indi-vidually and provided with their own measuring circuits.7 Welding Parameters for 2-Sheet Welds7.1 Standard Value TableThe values for electrode force, welding current, welding time an

36、d off periods indicated in Tables 1.1 and1.2 are standard values corresponding to the state of the art. These standard values may be adapted to the relevant joining task. Note that any change in the electrode force also results in necessary changes in the welding current amperage and, if applicable,

37、 the welding time. In addition, the range of adjustment to the welding current and therefore the process reliability are reduced for lower electrode forces while the tendency to spatter increases. This can be compensated for, however, by allowing longer welding times.The standard values indicated in

38、 Tables 1.1 and 1.2 refer to grade DC04 sheets with good fit. Electrode force allowances for coated sheets and higher material strengths and, if applicable, worse fit shall be taken into account.The reference sheet thickness tV forms the basis for the determination of parameters for unequal sheet th

39、icknesses. It can be calculated from tV = 0,8*t1 + 0,2*t2.The minimum spot diameter results from 14d P =, whereby t1 = tmin (see Section 11. A target diame-ter of 15, 5d P =shall be aimed at.The values for the minimum spot distance refer to direct welding without shunt compensation. With shunt compe

40、nsation, smaller spot distances are possible. This also serves to increase the depths of indentation, however.7.2 Electrode Force In the case of zinc-coated sheets with or without additional organic coating, the electrode force indi-cated in Table 1 shall be increased by approx. 10%. In the case of

41、higher-strength materials, the electrode force shall be increased as follows:H240 LA(D: 10%H320 LA(D: 15%H400 LA(D: 20% Materials with increased strength (yield strength > 400 MPa: 20 %, see Section 14. In the event of a poor fit, the electrode force indicated shall be increased appropriately dep

42、ending onthe thickness, material and fit problem. Within the material approval process, electrode forces shall be assured during the welding parameterdetermination. Examples of electrode force calculations:t 1 = 1,5 mm, H400LAt 2 = 1,75 mm, H320 LAtv = 0,8*1,5 mm + 0,2*1,75 mm = 1,55Standard value a

43、ccording to Table 1: 3800 N20% force allowance for H400LA: + 760 NElectrode force for welding task: 4560 Nt 1 = 2,0 mm, H320 LA, organically coatedt 2 = 2,0 mm, DC04, zinc-coatedStandard value according to Table 1: 4100 N15% force allowance for H320LA: + 615 N10% force allowance for zinc coating: + 410 NElectrode force for welding task: 5125 N7.3 Welding CurrentThe welding current values indicated in Tables 1.1 and 1.2 are values for initial programming and must be adapted to individual conditions. This applies, in particular, to the use of medium frequenc