1、 ENGINEERING MATERIAL SPECIFICATIONDate Action Revisions 2010 10 07 N-STATUS A1 replaced by WSS-M1P95-A1; A2 replaced by WSS-M1P95-A2; A3 replaced by WSS-M1P95-A3; A4 replaced by WSS-M1P95-A4. No replacement for A5 and A6 G. Weber, NA 2004 03 17 Revised Returned to active status, para 1, 2 and 5.2 r
2、evised B. Curtiss 1996 03 15 Activated P. Lee Printed copies are uncontrolled Copyright 2010, Ford Global Technologies, LLC Page 1 of 3 PLATING, TIN/ZINC ALLOY, ELECTROPLATED WSE-M1P93-A1/A2/A3/A4 OVER FERROUS SURFACES PLATING, TIN/ZINC ALLOY, MECHANICALLY WSE-M1P93-A5/A6 PLATED OVER FERROUS SURFACE
3、S NOT TO BE USED FOR NEW DESIGN 1. SCOPE These specifications define the requirements for electroplated or mechanically plated deposits and associated hexavalent chromium free coatings. 2. APPLICATION These specifications were released originally to define performance requirements for corrosion resi
4、stance and electrical conductivity, and are also suitable for general corrosion protection of non-electrical components. A supplementary hexavalent chromium free surface treatment must be applied to coated parts to retard formation of white corrosion products. 3. REQUIREMENTS 3.0 STANDARD REQUIREMEN
5、TS FOR PRODUCTION MATERIALS Material suppliers and part producers must conform to the Companys Standard Requirements For Production Materials (WSS-M99P1111-A). 3.2 CHEMICAL COMPOSITION Tin Zinc A1, A2, A3, A4, Weight % 60 - 80 20 - 40 A5, A6, Weight % 25 - 35 65 - 75 3.3 PLATING THICKNESS AND CORROS
6、ION RESISTANCE (ASTM B 659/ASTM B 117/ASTM B 487) Plating thickness requirements identified represent minimum values and apply to all significant surfaces unless otherwise specified on the Engineering Drawing. Note: In case of dispute, the thickness measurement umpire method shall be metallographic
7、sectioning per ASTM B 487. Evidence of basis metal red rust corrosion products on significant surfaces following testing when evaluated by the unaided eye at normal reading distance constitutes failure of the part. ENGINEERING MATERIAL SPECIFICATIONWSE-M1P93-A1/A6 Printed copies are uncontrolled Cop
8、yright 2010, Ford Global Technologies, LLC Page 2 of 3 Evidence of zinc/tin alloy white corrosion products on significant surfaces following salt spray testing when evaluated by the unaided eye at normal reading distance constitutes failure of the part due to breakdown of the supplementary surface t
9、reatment. This requirement applies to all supplementary surface treatments and supersedes any conflicting requirements governing supplementary surface treatments unless otherwise specified on the engineering drawing. 3.3.1 Plating Thickness Plating Thickness Micrometers, min A1 5 2 8A3 10 A4 13 A5 8
10、 A6 10 3.3.2 Corrosion Resistance Specification No. Salt Spray Hours White Corrosion Red Corrosion min min WSE-M1P93-A1 72 288 WSE-M1P93-A2 72 408 WSE-M1P93-A3 72 504 WSE-M1P93-A4 72 600 WSE-M1P93-A5 72 192 WSE-M1P93-A6 72 240 3.4 PLATING ADHESION (ASTM B 571) Adhesion of the electroplate to the bas
11、e metal must conform to the requirements of the following test methods per ASTM B 571 unless otherwise indicated. 3.4.1 Grind-Saw Test No lifting or peeling of the electroplate from the substrate is permitted following the grind-saw test. 3.4.2 Burnishing Test No blistering, lifting, or peeling of t
12、he electroplate from the substrate is permitted following the burnishing test. ENGINEERING MATERIAL SPECIFICATIONWSE-M1P93-A1/A6 Printed copies are uncontrolled Copyright 2010, Ford Global Technologies, LLC Page 3 of 3 3.5 EMBRITTLEMENT Parts plated to this specification shall be free from the detri
13、mental effects of hydrogen embrittlement or other factors which result in part brittleness. All parts shall meet the requirements of WSS-M99A3-A. 3.5.1 If hydrogen embrittlement relief via heat treatment is specified, post treatments will be performed after heat treatment. 5. GENERAL INFORMATION The
14、 information given below is provided for clarification and assistance in meeting the requirements of these specifications. 5.1 SIGNIFICANT SURFACES Unless otherwise specified on the engineering drawing, significant surfaces are defined as those surfaces of the finished part that: . Are directly visi
15、ble and/or visible by reflection when the finished part is assembled in position. . Can be the source of corrosion products directly visible or visible by reflection. 5.2 HEXAVALENT CHROMIUM FREE CONVERSION COATINGS Special finishes may be required on some parts, in which case the Engineering Drawin
16、gs will be marked accordingly. Zinc/tin plate plus hexavalent chromium free treatment; or zinc/tin plate plus black finish. Example: Zinc/tin plate per WSF-M1P93-A1, Class 1 plus hexavalent chromium free coating. In barrel operations the black post treatment may vary from dark greenish black, to slight iridescent black to total black just as long as the corrosion value requirements are met.
