1、This document is restricted and may not be sent outside Navistar, Inc. or reproduced without permission from Corporate Technical Standards. Suppliers are required to assume all patent liability. 2014 by Navistar, Inc. JUNE 2014 Page 1 of 6 NAVISTAR, INC. Material, Parts, and Process Specifications (
2、MPAPS) NUMBER: MPAPS G-20 Former Designation: CEMS G-20 TITLE: Zinc Plating CURRENT Rev. No.: 1406 DATE: June 2014 WRITTEN/REVIEWED BY: Materials Engineering APPROVED BY: Materials Engineering SUPERSEDES: CEMS G-20 - August 2009 PRINTED COPIES OF THIS DOCUMENT MUST BE VERIFIED FOR CURRENT REVISION T
3、his 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 applicability of regulatory l
4、imits prior to use. Change Notice: Changed to new MPAPS format; editorial changes. 1.0 SCOPE This specification covers Navistars requirements for electrodeposited zinc coatings on iron and steel substrates. Provision is also made to specify mechanical plated zinc coatings by the addition of a suffix
5、 “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 and Engineering Standard Parts. Typical parts include clips, clamps, brackets, small sta
6、mpings, tubes, rivets, rivnuts, lock bolt collars, screws, bolts and nuts, washers, and fittings. Zinc plated parts or their corrosion products must not come in contact with stressed polyamides (nylon 6 or 66) or PTFE (e.g., ball joints/raceways). 2.1 Restricted Chemical Substances Effective January
7、 1, 2007, all product supplied to the requirements of this specification must comply with the requirements of the MPAPS B-50 specification. 3.0 CONTENTS PAGE REFERENCE DOCUMENTS 1 CLASSIFICATION 2 GENERAL REQUIREMENTS 2 QUALITY 4 METHODS OF TEST 5 SOURCE APPROVAL AND QUALITY CONTROL 5 DESIGNATION ON
8、 DRAWINGS AND PURCHASE ORDERS 6 PACKING, SHIPPING AND IDENTIFICATION 6 TECHNICAL INFORMATION 6 NOTE: All product supplied to the requirements of this specification must be free of hexavalent chrome. NUMBER: MPAPS G-20 TITLE Zinc Plating REVISION: 1406 This document is restricted and may not be sent
9、outside Navistar, Inc. or reproduced without permission from Corporate Technical Standards. Suppliers are required to assume all patent liability. 2014 by Navistar, Inc. JUNE 2014 Page 2 of 6 4.0 REFERENCE DOCUMENTS Unless otherwise specified, the latest issue of all referenced standards shall apply
10、. The following standards, specifications and regulations 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 MPAPS B-50 NAVISTAR CEMS GT-5A ASTM B 4
11、99 5.0 CLASSIFICATION Zinc platings are classified by coating thickness and level of corrosion resistance, as described in Table 1 below. 6.0 GENERAL REQUIREMENTS Parts to be plated will be thoroughly cleaned and free of rust, scale, oil and other foreign matter. The cleaning operation must be contr
12、olled to prevent hydrogen embrittlement, especially 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
13、achieve. In this case, mechanical zinc plating will be specified on the engineering drawing by the addition of an “M” suffix to the Class designation (example: Class 8AM, etc.). 6.1 Plating Requirements 6.1.1 Passivation Treatments Zinc plating should always be given a passivating treatment to preve
14、nt the occurrence of white (zinc) corrosion products, unless there is a specific reason for the omission of this treatment. Hexavalent chromate conversion coatings are not permitted on zinc-plated parts supplied to Navistar or for parts used in Navistar products. The coating classes reflected in Tab
15、le 1 below assume use of trivalent chromium passivation or other hex-chrome free conversion coating. Requirements for each class of coating are shown below. 6.1.2 Zinc Plating and Paint Since some of the plating classes may require an additional sealer/topcoat over the zinc plating in order to achie
16、ve the required performance, this may not be desirable if plated parts will be subjected to further painting operations, such as chassis paint. In such cases, with prior approval from Engineering or Materials Engineering, the performance specified in the table may be waived and the acceptance criter
17、ia for the given class will be based on the plating thickness rather than salt spray performance or as specified on the engineering drawing or purchase order. 6.1.3 Transmission Oil Cooler Tubing Class 6A will be specified on drawings for transmission oil cooler (TOC) steel tubing/assemblies. In thi
18、s application, a minimum 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. Exceptions to this requirement may be specified on the engineering drawing. NUM
19、BER: MPAPS G-20 TITLE Zinc Plating REVISION: 1406 This document is restricted and may not be sent outside Navistar, Inc. or reproduced without permission from Corporate Technical Standards. Suppliers are required to assume all patent liability. 2014 by Navistar, Inc. JUNE 2014 Page 3 of 6 Table 1 CL
20、ASSIFICATION AND REQUIREMENTS Navistar Designation Min. plating thickness Neutral Salt Spray Test (ASTM B 117) Class * Obsolete Class m in. White Corrosion Red Rust Sealer Appearance (hours of test) (hours of test) 12A 12B, 13A/B, A, AC 12 0.0005 120 360 Optional Clear/silvery color 8F1,2 - 8 0.0003
21、 240 480 Required Clear/silvery color 8A 8B 8 0.0003 120 240 Optional Clear/silvery color 6A 6B, 5A/B,3A/B 6 0.0002 48 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 require
22、d. 1 Class 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
23、recommended 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
24、on drawing or unless approved by NAVISTAR Fastener Engineering. 2 For nylon insert locknuts, the only approved sealer is New Surface Technologies 440 Sealer. *Mechanical zinc plating will be specified on the engineering drawing by the addition of an “M” suffix to the Class designation (e.g., Class 8
25、AM, etc.). See paragraph 6.1.3 above for TOC lines. 6.2 Appearance and Color of Plated Parts In the past, when use of hexavalent chromate passivation was used on zinc plating, plated parts commonly exhibited a yellow iridescent coating appearance. However, that appearance was a function of that type
26、 of process, but zinc plating with trivalent chrome passivation is a clear/bright/silvery color. Provision of a yellow color (or 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 ord
27、er, the clear/bright/silvery color will be provided. Note that the addition of a color dye could possibly reduce corrosion 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 requir
28、ed minimum number of hours for the plating class designated in Table 1. Acceptable corrosion performance is defined as having no white corrosion or red rust after the specified hours of test. NUMBER: MPAPS G-20 TITLE Zinc Plating REVISION: 1406 This document is restricted and may not be sent outside
29、 Navistar, Inc. or reproduced without permission from Corporate Technical Standards. Suppliers are required to assume all patent liability. 2014 by Navistar, Inc. JUNE 2014 Page 4 of 6 Significant surfaces for evaluation of fasteners will be defined as all exposed surfaces of fastener(s) when instal
30、led, including but not limited to fastener heads, socket recesses, SEMS washers, and external surfaces of nuts. Threads 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 h
31、oles, edges, and tubing interiors are excluded unless otherwise specified on drawing. 6.4 Plating Thickness Thickness 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 pa
32、rts will be twice the minimum specified plating thickness, and is limited by the basic thread size and its associated 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 par
33、t meets all mechanical property requirements specified for the part. For plating having supplementary treatments (e.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
34、 will not blister, chip or flake after adhesion testing as described in Section 8.3. 6.6 Paintability Zinc plated parts 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. 7.0 QUALITY The z
35、inc 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 and will not flake off or develop “spotting out.” 7.1 Hydrogen E
36、mbrittlement 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 absorption. For electroplated zinc parts such as these, it will
37、 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 relieve hydrogen embrittlement. Generally, the bake operation will inv
38、olve heating in an oven until the part core temperature (not oven temperature) reaches 205-215 C (400-420 F), and holding at this temperature for 4 hrs minimum. Likewise, hardened parts which have been tempered at less than 175 C (350 F) should be heated at 150 C (300 F) for at least 8 hours. If the
39、 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.). NUMBER: MPAPS G-20 TITLE Zinc Plating REVISION: 1406 This
40、document is restricted and may not be sent outside Navistar, Inc. or reproduced without permission from Corporate Technical Standards. Suppliers are required to assume all patent liability. 2014 by Navistar, Inc. JUNE 2014 Page 5 of 6 7.2 Sampling Procedure Select for test one or more random samples
41、 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 rejected. 8.0 METHODS OF TEST 8.1 Plating Thickness Determine t
42、hickness of coating on significant surfaces (see Section 6.3 for definition) 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 necessary. 8.2 Salt Spray Testing Perform salt spra
43、y testing per ASTM B 117. 8.3 Plating Adhesion Sample 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 a hex-free chromate coating may be verified pe
44、r 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. 9.0 SOURCE APPROVAL AND QUALITY CONTROL 9.1 Supplier Requirements All supplie
45、rs to NAVISTAR are required to be registered to ISO 9001 Quality System Requirements. 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 certi
46、fication with an accredited registrar and must furnish copies of registration certificates to their Corporate Buyer upon request. 9.2 Approval Parts supplied against contracts or purchase orders citing this specification shall be equivalent in all respects to those samples that were approved by the
47、purchaser. No changes in formulation or processing practices are permitted without approval. In the event that changes in material, properties, processing practices, construction, color, or labeling of the product are required, the supplier shall notify NAVISTAR Materials Engineering and Purchasing
48、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 request for change. 9.3 Process Control The supplier shall either perform and report results of tests on specific lots of parts produced using ISO 9001 or TS-16949 guidelines, or provide statistical evidence of the lot having been produced in a state of statistical control a
