INTERN CEMS G-20-2008 Zinc Plating《电镀锌》.pdf

1、 NAVISTAR, INC. CEMS (CORPORATE ENGINEERING MATERIAL SPECIFICATION) NUMBER: CEMS G-20 TITLE: Zinc Plating CURRENT ISSUE DATE: August 2008 WRITTEN/REVIEWED BY: Materials Engineering APPROVED BY: Materials Engineering SUPERSEDES ISSUE OF: June 2007 PRINTED COPIES OF THIS DOCUMENT MUST BE VERIFIED FOR

2、CURRENT REVISION This specification may involve hazardous materials, equipment, and procedures. This specification does not purport to address all of the safety issues associated with its use. The user is responsible to consult appropriate safety and health practices and to determine the applicabili

3、ty of regulatory limits prior to use. Change Notice: Replaced “International Truck and Engine Corporation” with “Navistar, Inc.” per corporate directive; added note in 6.1 related to painting operations; revised Table 1 for Class 6A and added footnote 2; revised Section 6.3 related to definition of

4、corrosion performance; revised Section 6.6 related to paintability; editorial changes. NOTE: All product supplied to the requirements of this specification must be free of hexavalent chrome. 1.0 SCOPE This specification covers the Corporations requirements for electrodeposited zinc coatings. Provisi

5、on is also made to specify mechanical plated zinc coatings by the addition of a suffix “M” to the class designation. 2.0 INTRODUCTION Zinc plating is used primarily for corrosion resistance. This specification provides for several classes of zinc plating for use on both Engineering designed parts an

6、d Engineering Standard Parts. Typical parts include clips, clamps, brackets, small stampings, tubes, rivets, rivnuts, lock bolt collars, screws, bolts and nuts, washers, and fittings. 3.0 CONTENTS PAGE REFERENCE DOCUMENTS 1 CLASSIFICATION 2 GENERAL REQUIREMENTS 2 QUALITY 4 METHODS OF TEST 4 SOURCE A

7、PPROVAL AND QUALITY CONTROL 4 DESIGNATION ON DRAWINGS AND PURCHASE ORDERS 5 PACKING, SHIPPING AND IDENTIFICATION 5 TECHNICAL INFORMATION 5 4.0 REFERENCE DOCUMENTS Unless otherwise specified, the latest issue of all referenced standards shall apply. The following standards, specifications and regulat

8、ions are referenced in this specification. Quality System Standard ISO 9001 or TS-16949 ASTM B 117 ASTM B 695 NAVISTAR Manufacturing Standard MS-D-13 ASTM B 201 ASTM D 6492 CFR Title 29, Part 1910 ASTM B 487 NAVISTAR CEMS GT-5A ASTM B 499 This document is restricted and may not be sent outside Navis

9、tar, Inc. or reproduced without permission from Corporate Technical Standards. Suppliers are required to assume all patent liability. 2008 by Navistar, Inc. AUGUST 2008 Page 1 of 5 Copyright Navistar International Corporation Provided by IHS under license with INTERNNot for ResaleNo reproduction or

10、networking permitted without license from IHS-,-,-NUMBER: CEMS G-20 TITLE Zinc Plating CURRENT ISSUE DATE: AUGUST 2008 This document is restricted and may not be sent outside Navistar, Inc. or reproduced without permission from Corporate Technical Standards. 5.0 CLASSIFICATION Zinc platings are clas

11、sified by coating thickness and level of corrosion resistance, as described in Table 1 below. 6.0 GENERAL REQUIREMENTSParts to be plated will be thoroughly cleaned and free of rust, scale, oil and other foreign matter. The cleaning operation must be controlled to prevent hydrogen embrittlement, espe

12、cially in those parts that are hardened, cold worked, or subject to high service stresses. In the case of high strength, high hardness parts (see Section 7.1), mechanical plating may be preferred since relief of hydrogen embrittlement may be difficult to achieve. In this case, mechanical zinc platin

13、g will be specified on the engineering drawing by the addition of an “M” suffix to the Class designation (example: Class 8AM, etc.). 6.1 Passivation TreatmentsZinc coatings should always be given a passivating treatment to prevent the occurrence of white (zinc) corrosion products, unless there is a

14、specific reason for the omission of this treatment. Hexavalent chromate conversion coatings are not permitted on zinc-plated parts supplied to NAVISTAR. The coating classes reflected in Table 1 below assume use of trivalent chromium passivation or other hex-chrome free conversion coating. Requiremen

15、ts for each class of coating are shown below. Since some of the plating classes may require an additional sealer/topcoat over the zinc plating in order to achieve the required performance, this may not be desirable if plated parts will be subjected to further painting operations, such as chassis pai

16、nt. In such cases, with prior approval from Engineering or Materials Engineering, the performance specified in the table may be waived and the acceptance criteria for the given class will be based on the plating thickness rather than salt spray performance or as specified on the engineering drawing

17、or purchase order. Table 1 CLASSIFICATION AND REQUIREMENTS Navistar Designation Min. plating thickness Neutral Salt Spray Test (ASTM B 117) Sealer Appearance White Corrosion Red Rust Class * Obsolete Class m hours of test hours of test 12A 12B, 13A/B, A, AC 12 120 360 Optional Clear/silvery color 8F

18、1,2- 8 240 480 Required Clear/silvery color 8A 8B 8 120 240 Optional Clear/silvery color 6A6B, 5A/B,3A/B 648 96 Optional Clear/silvery color 1 - A flash deposit for identification, coloring, or temporary protection from corrosion while in transit. Not allowed Clear; passivation not required. 1 Class

19、 8F includes application of a post-plating sealer (dip solution) for added abrasion resistance and corrosion protection for fasteners. This class would be recommended for use on heavy duty fasteners (such as hex bolts) which would not be subjected to further painting operations. It is not recommende

20、d for smaller parts, such as screws. Use of Class 8F for a given part must be specified on the engineering drawing or in the applicable Engineering Standard Parts specification. Also, no torque-tension fluid or wax (in addition to any sealer) will be added to a given part unless specified on drawing

21、 or unless approved by TDTC Fastener Engineering. 2 For nylon insert locknuts, the only approved sealer is New Surface Technologies 440 Sealer.Suppliers are required to assume all patent liability. 2008 by Navistar, Inc. AUGUST 2008 Page 2 of 5 Copyright Navistar International Corporation Provided b

22、y IHS under license with INTERNNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-NUMBER: CEMS G-20 TITLE Zinc Plating CURRENT ISSUE DATE: AUGUST 2008 This document is restricted and may not be sent outside Navistar, Inc. or reproduced without permission from Corporat

23、e Technical Standards. *Mechanical zinc plating will be specified on the engineering drawing by the addition of an “M” suffix to the Class designation (e.g., Class 8AM, etc.). Class 6A will be specified on drawings for transmission oil cooler (TOC) steel tubing/assemblies. In this application, a min

24、imum plating thickness of 4 microns will be allowed as long as the salt spray performance is demonstrated to meet a minimum of 24 hr to white corrosion and 96 hrs to red rust on formed areas of tubes. 6.2 Appearance and Color of Plated PartsIn the past, when use of hexavalent chromate passivation wa

25、s used on zinc plating, plated parts commonly exhibited a yellow iridescent coating appearance. However, that appearance was a function of that type of process, and use of trivalent chromium passivation coatings now produces a clear/bright/silvery coating appearance. Provision of a yellow color (or

26、other colors) in trivalent passivation coatings can only be achieved with the addition of a color dye. Unless a specific color is designated on the drawing or purchase order, the clear/bright/silvery color will be provided. Addition of a color dye may not improve and could possibly reduce corrosion

27、performance. 6.3 Corrosion Performance Parts plated according to the requirements of this specification will be capable of withstanding neutral salt spray testing for the required minimum number of hours for the plating class designated in Table 1. Acceptable corrosion performance is defined as havi

28、ng no white corrosion or red rust after the specified hours of test. Significant surfaces for evaluation of fasteners will be defined as all exposed surfaces of fastener(s) when installed, including but not limited to fastener heads, socket recesses, SEMS washers, and external surfaces of nuts. Thre

29、ads and points are excluded unless otherwise specified on drawing. On parts other than threaded fasteners, significant surfaces will include all plated surfaces; deep recesses, blind holes, edges, and tubing interiors are excluded unless otherwise specified on drawing. 6.4 Plating Thickness Thicknes

30、s of zinc plating on parts supplied to this specification shall meet the minimum plating requirements for the applicable class as specified in Table 1. Maximum thickness on threaded parts will be twice the minimum specified plating thickness, and is limited by the basic thread size and its associate

31、d tolerances. Coated fasteners must pass all appropriate Thread Go gages for thread sizing. Threads may be produced undersized prior to plating providing that the finished threaded part meets all mechanical property requirements specified for the part. For plating having supplementary treatments (e.

32、g., sealers), plating thickness values apply after application of treatment. Plating thickness will not include other treatments such as oils, waxes, etc. 6.5 Adhesion Plating on parts will not blister, chip or flake after adhesion testing as described in Section 8.3. 6.6 Paintability Zinc plated pa

33、rts must be compatible with plant paint systems. They shall provide good adhesion to chassis paint and must meet minimum 90% adhesion level when tested to CEMS GT-5A. Suppliers are required to assume all patent liability. 2008 by Navistar, Inc. AUGUST 2008 Page 3 of 5 Copyright Navistar Internationa

34、l Corporation Provided by IHS under license with INTERNNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-NUMBER: CEMS G-20 TITLE Zinc Plating CURRENT ISSUE DATE: AUGUST 2008 This document is restricted and may not be sent outside Navistar, Inc. or reproduced without

35、permission from Corporate Technical Standards. 7.0 QUALITY The zinc coating will be dense and uniform, free from porosity, pinholes and blisters, and substantially free from other defects that may affect the appearance or protective value of the coating. The plating will have no gray or burned area

36、and will not flake off or develop “spotting out”. 7.1 Hydrogen Embrittlement All steel parts having core hardness greater than 32 HRC or surface hardness of 35 HRC, as well as all highly stressed cold worked parts subsequently electroplated with zinc, are subject to embrittlement because of hydrogen

37、 absorption. For electroplated zinc parts such as these, it will be the responsibility of the supplier to ensure that supplied parts are free of hydrogen embrittlement and to see that such parts are baked within one hour of electroplating (but before any supplementary coatings are applied) to reliev

38、e hydrogen embrittlement. Generally, the bake operation will involve heating in an oven until the part core temperature (not oven temperature) reaches 205-215C (400-420F), and holding at this temperature for 4 hrs minimum. Likewise, hardened parts which have been tempered at less than 175C (350F) sh

39、ould be heated at 150C (300F) for at least 8 hours. If the part to be plated is considered susceptible to failure because of hydrogen embrittlement, mechanical zinc plating may be specified on the engineering drawing by the addition of an “M” suffix to the Class designation (e.g., Class 8AM, etc.).

40、7.2 Sampling ProcedureSelect for test one or more random samples from each shipment, or from authorized test specimens. The number of samples to be selected from each size lot will be agreed upon between the supplier and the purchaser. If results fall below the test requirements, the shipment may be

41、 rejected. 8.0 METHODS OF TEST 8.1 Plating ThicknessDetermine thickness of coating on significant surfaces (see Section 6.3) using the eddy current (magnetic) method (ASTM B 499), the x-ray method, or the microscopic method (ASTM B 487). The microscopic method will be used as a referee test when nec

42、essary. 8.2 Salt Spray TestingPerform salt spray testing per ASTM B 117. 8.3 Plating AdhesionSample plated parts will be exposed to 220C for 30 minutes, followed by quenching in water at room temperature. After quenching, parts will not blister, flake, or chip. 8.4 Passivation Treatment Presence of

43、a hex-free chromate coating may be verified per certification by the plater. When necessary for referee purposes, presence of clear chromate coatings may be determined per ASTM B 201. The absence of hexavalent chrome may be demonstrated using ASTM D 6492, as required. Suppliers are required to assum

44、e all patent liability. 2008 by Navistar, Inc. AUGUST 2008 Page 4 of 5 Copyright Navistar International Corporation Provided by IHS under license with INTERNNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-NUMBER: CEMS G-20 TITLE Zinc Plating CURRENT ISSUE DATE: AUG

45、UST 2008 This document is restricted and may not be sent outside Navistar, Inc. or reproduced without permission from Corporate Technical Standards. 9.0 SOURCE APPROVAL AND QUALITY CONTROL9.1 Supplier RequirementsAll suppliers to NAVISTAR are required to be registered to ISO 9001 Quality System Requ

46、irements. NAVISTAR will also accept TS-16949 registration as long as the supplier can also fulfill all AIAG PPAP (Production Part Approval Process) documentation and approval requirements. Suppliers must maintain their certification with an accredited registrar and must furnish copies of registratio

47、n certificates to their Corporate Buyer upon request. 9.2 ApprovalParts supplied against contracts or purchase orders citing this specification shall be equivalent in all respects to those samples that were approved by the purchaser. No changes in formulation or processing practices are permitted wi

48、thout approval. In the event that changes in material, properties, processing practices, construction, color, or labeling of the product are required, the supplier shall notify Materials Engineering (TDTC) and Purchasing and Supplier Development of the proposed change(s). Test data indicating conformance to all requirements of this specification, test samples, and new or amended or updated Material Safety Data Sheet(s) (MSDS), in accordance with CFR Title 29, Part 1910 shall be submitted with the