1、 ENGINEERING MATERIAL SPECIFICATIONDate Action Revisions Ver 4 2008 04 25 Revised Para 3.2 para 3.1, 3.6, 4 deleted 1987 08 03 Released SM/ER112TC H Nikkel, NAAO; NP Riley, EAO Printed copies are uncontrolled Copyright 2008, Ford Global Technologies, LLC Page 1 of 2 PLATING, HARD CHROMIUM WSE-M1P14-
2、B 1. SCOPE This specification defines performance requirements for electrodeposited hard chromium on metal surfaces. 2. APPLICATION This specification was released originally to define performance criteria for an electrodeposited hard chromium finish for applications requiring a scuff, wear, and hea
3、t resistant surface. These include engine valve stems, piston rings, and piston rods for suspension dampers. 3. REQUIREMENTS 3.0 STANDARD REQUIREMENTS FOR PRODUCTION MATERIALS Material suppliers and part producers must conform to the Companys Standard Requirements For Production Materials (WSS-M99P1
4、111-A). All requirements identified for each specification must be met to achieve acceptable field durability. No one requirement, exclusive of others, is capable of ensuring satisfactory performance. Any deviations to the requirements of these specifications may be subject to additional performance
5、 requirements. All part testing requirements apply to those areas of the part identified as a significant surfaces (see General Information) unless otherwise specified on the engineering drawing. Parts shall be free from the detrimental effects of hydrogen embrittlement or other factors which result
6、 in part brittleness. Follow the requirements in WSS-M99A3-A. 3.1 PLATING ADHESION (ASTM B 571) Adhesion of the electroplate to the base metal must conform to the requirements of the grind-saw test method per ASTM B 571 unless otherwise indicated. This test shall be performed both before and after h
7、eating for 4 h at 175 +/- 2 C. No lifting or peeling of the electroplate from the substrate is permitted following the grind-saw test. For chromium plated engine valves, plating adhesion shall be assessed by the bend test in which the valve stem is formed through 90 over a 10 mm radius. Tensile and
8、compression surfaces shall show no flaking when viewed at 10 X magnification; cracking is permitted at these locations. In addition, the finished part shall exhibit no macro cracking, peeling, blisters or flaking when viewed at a nominal magnification X 20 but blemishes and pearls within the master
9、sample range are permitted. Comparison standards, test procedures for bend test and appearance shall form part of the agreed control plan. ENGINEERING MATERIAL SPECIFICATIONWSE-M1P14-B Printed copies are uncontrolled Copyright 2008, Ford Global Technologies, LLC Page 2 of 2 3.2 PLATING THICKNESS (AS
10、TM B 659) It is the suppliers responsibility to identify the plating thickness distribution for each unique part design and rack design by mapping the plating racks and plated parts and to employ any special processing techniques, e.g., the use of auxiliary anodes and/or shields, reducing the number
11、 of parts per rack etc., which may be required to consistently meet the specified minimum plating thicknesses on all significant surfaces. The Engineering Drawing should specify the minimum and maximum plating thickness for the hard chrome plating. If not specified on the engineering drawing, the fo
12、llowing limits apply for all significant surfaces. Engine valves 5.1 9.1 m Piston Rings 5.0 m min. Damper Piston Rods 10.0 m min. In case of dispute the umpire test method for measuring thickness shall be metallographic sectioning per ASTM B 487. 3.3 CLEANING PRIOR TO ELECTROPLATING It is the suppli
13、ers responsibility to identify the correct cleaning method per the principles defined in ASTM B177, Standard Guide for Engineering Chromium Electroplating. 4. GENERAL INFORMATION The information given below is provided for clarification and assistance in meeting the requirements of this specificatio
14、n. 4.1 SIGNIFICANT SURFACES Significant surfaces are all surfaces specified on the engineering drawing requiring a controlled deposit. Unless otherwise specified on an engineering drawing, only those areas that can be touched with a 20 mm diameter ball shall be considered significant. In holes, corn
15、ers, recesses and other areas where a controlled deposit cannot be obtained under normal electroplating conditions, the thickness of the deposit may be that which results from control on the significant surfaces, unless otherwise specified. 5. SUMMARY OF REVISIONS 2008 04 25 1. Renumbered paragraphs
16、. 2. Added piston rings, engine valve stems, and suspension damper, piston rods to the application description. 3. Added default thickness requirements for valves, rings, and rods. 4. Changed cleaning method from the general electroplate methods ASTM B 242 and B 183 to ASTM B 177 which is specific to cleaning for hard chrome deposits. 1990 09 28 C01031540, Revised 3.2 W Janssen N Riley EAO H Nikkel NAAO
