1、 ENGINEERING MATERIAL SPECIFICATION Material Name Specification Number Date Action Revisions Rev 03 2011 12 15 N Status No Usage S. Ryzyi, NA 2002 09 30 Revised Updated and renumbered 1989 06 01 SM/ER3033TC Released R Cooper/N Riley EAO CA McKenney NAAO Printed copies are uncontrolled Page 1 of 2 Co
2、pyright 2011, Ford Global Technologies, Inc. MALLEABLE IRON - PISTON RINGS, (PEARLITIC) WSD-M1A302-A1 NOT TO BE USED FOR NEW DESIGN 1. SCOPE The material defined by this specification is a temper aggregate graphite iron, with a pearlitic matrix. 2. APPLICATION This specification was released origina
3、lly for materials used in the production of piston rings. 3. REQUIREMENTS Material specification requirements are to be used for initial qualification of materials. 3.1 STANDARD REQUIREMENTS FOR PRODUCTION MATERIALS Material suppliers and part producers must conform to the Companys Standard Requirem
4、ents For Production Materials (WSS-M99P1111-A). 3.2 CHEMICAL COMPOSITION (weight %, ladle analysis) Carbon (total) 2.7 3.3 Silicon 1.5 3.0 Phosphorus 0.5 max Sulphur 0.1 max Chromium 0.5 1.0 Vanadium 0.1 0.4 Manganese, Nickel and Molybdenum can be added to a maximum of 1.0 % each, Copper up to 1.5 %
5、 maximum. Note: Manganese must be present in sufficient quantity to balance the Sulphur i.e. (1.7 x S %) + 0.2 min. Carbon equivalent and alloying elements shall be controlled within the above range to accommodate the ring section, size and method of casting (static/centrifugal are acceptable). The
6、anticipated working range for each component shall be restricted to a limited band within the above. ENGINEERING MATERIAL SPECIFICATION WSD-M1A302-A1 Page 2 of 2 Copyright 2011, Ford Global Technologies, Inc. 3.3 HARDNESS HB 273 - 325 HRC 28 - 35 HRB 104 - 108 An average of three results taken (1) a
7、djacent to the gap, (2) 90 degrees to the gap and (3) opposite the gap. Any other position will be within 10 HB points, 2 Rockwell B or C points. In the case of dispute, the umpire test method will be HB. 3.4 MICROSTRUCTURE Graphite - Uniformally distributed aggregates of secondary temper graphite A
8、STM A247,predominantly form III (produced by heat treatment of a white cast iron). Primary graphite form VII types A, B & C are not permitted, while types D and E graphite flakes are to be avoided or kept below 5 % by (area). Matrix - Fine pearlite (preferably lamellar but some spheroidised allowed)
9、 with a uniform distribution of fine isolated carbide particles between 5 - 20 % by area. Measurement should be averaged over a minimum field of 2mm dia, at a magnification which for arbitration will be X 200. 3.5 BENDING STRENGTH, min (unless otherwise stated on the drawing). (BS 5341 or equivalent
10、 ISO) 750 MPa 4. GENERAL INFORMATION The information given below is provided for clarification and assistance in meeting the requirements of this specification. 4.1 MODULUS OF ELASTICITY, Nominal. 158 GPa (BS 5341 part 4) NOTE: The actual values of modulus are adjusted to match the individual requirements of each ring design. In the absence of a complete ring a measure of Bending Strength can be obtained by the skin stress test as defined in BS 5341, in which case the following minimum result should apply: 950 MPa
