1、 ENGINEERING MATERIAL SPECIFICATION Material Name Specification Number Date Action 2002 07 31 Revised Updated and renumbered 1992 11 25 C10261077 Released W.Jones EAO C.J.Webster NAAO Printed copies are uncontrolled Page 1 of 3 Copyright 2002, Ford Global Technologies, Inc. STEEL, MARTENSITIC, VALVE
2、, WROUGHT WSD-M1A314-A1/A2 1. SCOPE The materials defined by this specification are a range of wrought martensitic alloy steels, including a chromium-silicon alloy steel. 2. APPLICATION This specification was released originally for material used for one piece intake valves, and stems of two piece v
3、alves for reciprocating engines. WSD-M1A314-A2 is a more appropriate selection for stem applications of two piece valves. 3. REQUIREMENTS 3.1 STANDARD REQUIREMENTS FOR PRODUCTION MATERIALS Material suppliers and part producers must conform to the Companys Standard Requirements For Production Materia
4、ls (WSS-M99P1111-A). 3.2 CHEMICAL COMPOSITION (WEIGHT %) A1 A2 Carbon 0.40 - 0.50 0.37 - 0.50* Manganese 0.80 max 0.50 - 1.0* Silicon 2.70 - 3.50 0.40 max Phosphorus 0.040 max 0.040 max Sulphur 0.030 max 0.040 max Chromium 8.00 - 10.00 1.25* Nickel 0.50 max 1.10 max * Molybdenum - 0.25 max* Iron Rem
5、ainder Remainder *Particular overall composition selected will be dependant on required weldability, hardenability and performance requirements. Minor variation to the above composition will be permitted providing all other specification/performance requirements are met and that the composition is a
6、pproved at control plan stage. See para 4.1 for alternative proven specifications where available. ENGINEERING MATERIAL SPECIFICATION WSD-M1A314-A1/A2 Page 2 of 3 Copyright 2002, Ford Global Technologies, Inc. 3.3 PART HARDNESS Unless otherwise specified on the (ASTM E 18) Engineering drawing 3.3.1
7、General One piece/stem of two piece valves 30 - 40 HRC* * Areas remote from weld and induction hardened heat affected zones, cold work, chromium plating and other finishes and curved surface correction to be applied where applicable. 3.3.2 Induction Hardened Surfaces Collet Groove, min 50 HRC Tip, m
8、in 53 HRC Valve Seat, min 42 HRC Curved surface correction to be applied where appropriate. 3.4 HEAT TREATMENT The material shall be heated uniformly within the austenite phase field and quenched by a suitable medium to produce optimum hardness. Hardening shall be followed by reheating and tempering
9、 at a temperature shown below: WSD-M1A314-A1 Austenitising 1020 - 1050 C Tempering 590 - 750 C WSD-M1A314-A2 Austenitising 825 - 880 C Tempering 500 - 650 C All heat treatment process parameters including any local hardening will form part of control plan. 3.5 MICROSTRUCTURE General microstructure (
10、para 3.3.1), shall be uniform tempered martensite. In the areas of process rehardened heat affected zones up to 5 and 10 %, by area, of ferrite and retained austenite, respectively, shall be permitted. A uniform distribution of carbides no larger than 0.025 mm maximum dimension shall be present. Ind
11、uction hardened surfaces (para 3.3.2) which are ground or machined shall be free from total decarburization, overheating and scale. 3.6 GRAIN SIZE (ASTM E 112) The prior austenite grain size shall be ASTM Number 5 or finer. ENGINEERING MATERIAL SPECIFICATION WSD-M1A314-A1/A2 Page 3 of 3 Copyright 20
12、02, Ford Global Technologies, Inc. 3.7 CLEANLINESS (ASTM A 295 and ASTM E 45, Plate III, Method A) Valve steel shall meet the minimum cleanliness requirements when tested in accordance with the above specifications. A B C D Thin Heavy Thin Heavy Thin Heavy Thin Heavy 2.5 2.0 2.0 2.0 2.0 2.0 2.0 2.0
13、4. GENERAL INFORMATION 4.1 ALTERNATIVE SPECIFICATIONS The following materials have proven satisfactory for intended applications: A1 A2 BS 970 401S45 530H40 DIN 1.4718(17007) 41Cr4(17200) SAE HNV 3(J775) 8645 ISO Type1(683 XV) Type3(683 III) 4.2 MICROSTRUCTURES Area fraction of microstructure constituents may be determined in accordance with ASTM E 562 or appropriate image analyzing system.
