1、 ENGINEERING MATERIAL SPECIFICATION Date Action Revisions Rev 04 2012 12 04 N Status No replacement or usage G. Weber, NA 2004 03 17 Revised Returned to active status, rev para 2. and 5.2 B. Curtiss 1988 03 22 RD-885100-210 Released C. Carter Controlled document at www.MATS Copyright 2012, Ford Glob
2、al Technologies, LLC Page 1 of 2 PLATING, ZINC COBALT OVER FERROUS SURFACES WSH-M1P86-A NOT TO BE USED FOR NEW DESIGN 1. SCOPE This specification defines performance requirements for an electrolytically deposited alloy coating of zinc cobalt. 2. APPLICATION This specification was released originally
3、 to define performance requirements for zinc cobalt alloy coatings where corrosion protective and/or decorative finishes on ferrous surfaces are required. A supplementary trivalent chromium or hexavalent chromium free treatment may be applied to the coated parts to retard the formation of white corr
4、osion products. 3. REQUIREMENTS All requirements identified for each specification must be met to achieve acceptable field durability. No one requirement, exclusive of others, is capable of insuring satisfactory performance. Any deviations to the requirements of this specification may be subject to
5、additional performance requirements. 3.0 STANDARD REQUIREMENTS FOR PRODUCTION MATERIALS Material suppliers and part producers must conform to the Companys Standard Requirements For Production Materials (WSS-M99P1111-A). 3.2 PLATING THICKNESS AND CORROSION RESISTANCE , min Specification Plating Salt
6、Spray Number Thickness Test Duration Micrometers hours WSH-M1P86-A 8.0 240 3.2.1 Plating Thickness (ASTM B 659) The plating thickness requirement identified above represents minimum values and applies to all significant surfaces unless otherwise specified on the Engineering Drawing. Note: In case of
7、 dispute, the thickness measurement umpire method shall be metallographic sectioning per ASTM B 487. 3.2.2 Accelerated Corrosion Resistance (Salt Spray) (ASTM B 117) Evidence of basis metal red rust corrosion products on significant surfaces following testing when evaluated by the unaided eye at nor
8、mal reading distance constitutes failure of the part. ENGINEERING MATERIAL SPECIFICATION WSH-M1P86-A Copyright 2012, Ford Global Technologies, LLC Page 2 of 2 Note: All part testing requirements apply to those areas of the part identified as a significant surface per para 5.1 unless otherwise specif
9、ied on the engineering drawing. 3.2.3 Cobalt Content The cobalt content in the deposited layer shall be 0.3 to 1.0%. Suitable methods for determining the cobalt content include Inductively Coupled Plasma (ICP), Directly Coupled Plasma (DCP) or other spectrographic techniques, such as Atomic Absorpti
10、on. 3.3 PLATING ADHESION (ASTM B 571) Adhesion of the electroplate to the base metal must conform to the requirements of the following test methods per ASTM B 571 unless otherwise indicated: 3.3.1 Grind-Saw Test No lifting or peeling of the electroplate from the substrate is permitted following the
11、grind-saw test. 3.3.2 Burnishing Test No blistering, lifting, or peeling of the electroplate from the substrate is permitted following the burnishing test. 3.4 EMBRITTLEMENT Parts plated to this specification shall be free from the detrimental effects of hydrogen embrittlement or other factors which
12、 result in part brittleness. All parts shall meet the requirements of WSS-M99A3-A. 5. GENERAL INFORMATION The information given below is provided for clarification and assistance in meeting the requirements of this specification. 5.1 SIGNIFICANT SURFACES Unless otherwise specified on the engineering
13、 drawing, significant surfaces are defined as those surfaces of the finished part that: Are directly visible 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 C
14、ONVERSION COATINGS Special finishes may be required on some parts, in which case the Engineering Drawings will be marked accordingly: zinc/cobalt plate* plus hexavalent chromium free treatment; or zinc/cobalt plate* plus bright finish. *Example: Zinc/cobalt plate per WSH-M1P86-A1 plus trivalent chrome and/or hexavalent chromium free coating.
