1、 ENGINEERING MATERIAL SPECIFICATION Material Name Specification Number Date Action Revision 2010 02 18 N-STATUS Replaced by EN 1563 GJS-800-2 L. Sinclair, NA 2002 07 22 Revised Updated and renumbered 1970 05 20 EC/64655SP Released Printed copies are uncontrolled Page 1 of 2 Copyright 2010, Ford Glob
2、al Technologies, Inc. CAST IRON - NODULAR GRAPHITE (NORMALISED AND TEMPERED GRADE) S-M1A4524-A NOT TO BE USED FOR NEW DESIGN 1. SCOPE This specification defines the requirements of a normalised and tempered pearlitic nodular iron. 2 APPLICATION This specification was released originally for material
3、 used for follower arms which will be tuftrided and induction hardened. 3. REQUIREMENTS 3.1 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 CHEMICAL COMPOSITION (%)
4、OPTIONAL Carbon 3.60 - 3.90 3.60 - 4.10 Silicon 1.90 - 2.20 1.60 - 2.20 Manganese 0.50 - 0.70 0.50 - 0.80 Phosphorus 0.08 maximum maximum 0.08 Sulphur 0.02 maximum maximum 0.03 Copper 0.40 - 0.6 - Magnesium 0.035- 0.060 as required CE 4.7 maximum 3.3 HARDNESS The hardness after normalising and tempe
5、ring must be 250/300 HB. 3.4 MICROSTRUCTURE - After Normalising and Tempering 3.4.1 GRAPHITE FORM Nodular ENGINEERING MATERIAL SPECIFICATION S-M1A4524-A Page 2 of 2 Copyright 2010, Ford Global Technologies, Inc. 3.4.2 NODULARITY ASTM A247 90 % minimum types I and II. Size 4 to 5. 3.4.3 MATRIX Fine p
6、earlite with not more than 5 % free ferrite randomly dispersed. 3.4.4 PRIMARY CARBIDES Randomly dispersed primary carbide is allowed up to a maximum of 1 %. 3.4.5 MARTENSITE Martensite or tempered martensite structures are not permitted. 3.5 HEAT TREATMENT 3.5.1 PRIMARY CARBIDE DECOMPOSITION The cas
7、tings must be given a primary carbide decomposition heat treatment at a temperature and time sufficient to ensure that requirement 3.4.4 of the specification is met. 3.5.2 NORMALISING The castings must be austenitised at 900 C for 1 hour. If the normalising treatment is combined with the carbide dec
8、omposition heat treatment, the castings must be held at 900 C for 1/2 hour immediately prior to air cooling. In all cases, the castings must be air cooled from 900 C at a rate sufficient to insure that the desired final microstructure is obtained. The air cooling rate must not be rapid enough to pro
9、duce martensitic castings. An air cooling rate range of 80 to 230 C per minute minimum from 900 C to 500 C should produce satisfactory casting microstructure. 3.5.3 TEMPERING The castings must be tempered for a minimum of 8 hours. The minimum tempering temperature permitted is 590 C. Longer tempering times or higher temperatures are permitted if required to produce castings within the required hardness range. 3.5.4 DECARBURISATION Decarburisation on finish machined surfaces is not permitted.
