1、 WORLDWIDE ENGINEERING STANDARDS Material Specification GMW16789 Exhaust Manifold Casting Variation Acceptance Standard Copyright 2012 General Motors Company All Rights Reserved July 2012 Originating Department: North American Engineering Standards Page 1 of 5 1 Scope 1.1 Material Description. The o
2、bjective of this specification is to minimize visual surface anomalies. This specification defines the acceptance limits of several types of surface anomalies. Also, described herein, are internal casting discontinuity limits. 1.2 Symbols. Not applicable. 1.3 Typical Applications. This specification
3、 applies to surface and internal casting anomalies of any exhaust manifold casting or the cast portion of any maniverter, regardless of the process or exhaust manifold material, including, but not exclusively, GMW13 and GMW3164. 1.4 Remarks. Various areas of an exhaust manifold are subject to differ
4、ent stresses. During the visual inspection phase of process monitoring, particular attention shall be paid to casting anomalies such as shrinks, inclusions, blows, excess metal resulting from core or mold chip-out that could affect flow or clearance, flash, porosity, and machining defects all of whi
5、ch may have a deleterious effect on the exhaust manifold (or maniverter) strength if permitted to exceed a certain size in specific locations. 2 References Note: Only the latest approved standards are applicable unless otherwise specified. 2.1 External Standards/Specifications. ASTM E446 2.2 GM Stan
6、dards/Specifications. GMW13 GMW3164 GMW3059 2.3 Additional References. TMC003 Material Safety Data Sheet guidance documents (available at ). 3 Requirements 3.1 Part Condition. These visual standards are applicable for the final machined product. The casting must be clean, and free from any core sand
7、, machining chips, debris, or burrs. Cosmetic imperfections in the casting surface resulting from normal processing operations are allowed in hidden areas. Oxidation/rust on the exhaust manifold machined surfaces is allowable as long as it conforms to the surface finish specification and must not fl
8、ake or chip off. Red/brown oxide, whether spotty or covering up to 50% of the manifold including machined surfaces, is acceptable. See Figure A1 in Appendix A. 3.2 Inspection Process. Inspection is to be performed with the naked eye as natural vision or corrected vision to 20/20. No magnification is
9、 to be used. 3.3 Total Discontinuities Allowed. No more than 6 total casting surface anomalies allowed per casting in any combination using this specification. The limit does not apply to casting discontinuities that are 1.0 mm or less. See Figure A2 and Tables A1 thru A3 in Appendix A. 4 Manufactur
10、ing Process Not applicable. Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW16789 Copyright 2012 General Motors Company All Rights Reserv
11、ed July 2012 Page 2 of 5 5 Rules and Regulations 5.1 Legal Regulations. All materials must satisfy applicable laws, rules, regulations and recommendations valid in the country of usage. 5.2 Language. In the event of conflict between the English and domestic language, the English language shall take
12、precedence. 5.3 Inspection and Rejection. Samples of components or materials released to a GM material specification shall be tested for conformity with the requirements of this material specification and approved by the responsible Engineering department prior to commencement of delivery of bulk su
13、pplies. A new approval must be received for any changes, e.g., properties, manufacturing process, location of manufacture, etc. If not otherwise agreed, all testing and documentation normally required for initial release must be completed. It is the responsibility of the supplier to inform the custo
14、mer in a timely manner, without solicitation, and to include documentation of all modifications of materials and/or processes and to apply for a new release. If not otherwise agreed, all release tests shall be repeated and documented by the supplier prior to commencement of delivery of non-conformin
15、g bulk supplies. In individual cases, a shorter test can be agreed to between the responsible Engineering department and the supplier. 5.4 Initial Source Approval. No shipments shall be made by any supplier until representative initial production samples have been approved by the appropriate Materia
16、ls Engineering department(s) as meeting the requirements of this specification. 5.5 Material Safety Data Sheets/Safety Data Sheets (MSDS/SDS). For new product submissions, or when a change in chemical composition of an existing product has occurred, a complete copy of the Material Safety Data Sheet/
17、Safety Data Sheet must be submitted in compliance with the Globally Harmonized System of Classification and Labeling of Chemicals (GHS) requirements or other country-specific MSDS/SDS requirements. In addition, product MSDS/SDS submissions must be in compliance with specific country General Motors T
18、MC003 Material Safety Data Sheet/Safety Data Sheet guidance documents where available. 5.6 All materials supplied to this standard must comply with the requirements of GMW3059, Restricted and Reportable Substances for Parts. 6 Approved Sources Engineering qualifications of an approved source are req
19、uired for this standard. Only sources listed in the GM Materials File (i.e., GM Supply Power) under this standard number have been qualified by engineering as meeting the requirements of this standard. For other GM locations, the responsible engineering group should be contacted to obtain the approv
20、ed source in that individual country. 7 Notes 7.1 Glossary. Blows: Gas entrapments in castings, causing voids in the metal. Dings/Dents: A small bump or depression in metal leaving an impression, sometimes caused by careless handling or storage. Fin: Metal on a casting caused by an imperfect joint i
21、n the mold. Flash: A thin section or fin of metal formed at the mold, core or in parting of a casting due to the cope and drag not matching completely or where core and core print do not match. Gate: The portion of a runner in a mold through which molten metal enters the mold cavity. Inclusions: Par
22、ticles of foreign material in a metallic matrix. The particles are usually compounds (such as oxides, sulfides, or silicates) but may be of any substance that is foreign to the matrix. Maniverter: A combination of exhaust manifold and exhaust converter. Oxide: The result of a metalloid or metal, or
23、a combination thereof, combining with oxygen. There is usually a color change. Porosity: Voids or pores resulting from trapped air or other gases or from shrinkage during the cooling phase of casting. Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for R
24、esaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW16789 Copyright 2012 General Motors Company All Rights Reserved July 2012 Page 3 of 5 Rust: A series of iron oxides formed by the reaction of iron with oxygen in the presence of water. Shr
25、ink: Dimensional change per unit length of the casting as it solidifies in the mold and cools to room temperature after removal from the mold. 7.2 Acronyms, Abbreviations, and Symbols. GHS Globally Harmonized System of Classification and Labeling of Chemicals GSSLT Global Subsystem Leadership Team M
26、SDS Material Safety Data Sheet SDS Safety Data Sheet 8 Coding System This standard shall be referenced in other documents, drawings, etc., as follows: Material per GMW16789 9 Release and Revisions This standard was originated in March 2012. It was first approved by the Non-ferrous Metals and Casting
27、s GSSLT in July 2012. It was first published in July 2012. Issue Publication Date Description (Organization) 1 JUL 2012 Initial publication. Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license
28、 from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW16789 Copyright 2012 General Motors Company All Rights Reserved July 2012 Page 4 of 5 Appendix A Figure A1: Example of Red/Brown Oxide Covering Up to 50% of the Manifold Note: Zones are colored blue, red and green. Figure A2: An Exhaust Manifold Di
29、vided into Zones Having Different Acceptance Levels for Various Casting Anomalies Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW16789 C
30、opyright 2012 General Motors Company All Rights Reserved July 2012 Page 5 of 5 Table A1: Description of the Zones in Figure A2 Zone 1: Blue 1.1 Non-machined cast surfaces. 1.2 Machined flange surfaces the first 1.0 mm zone around each cast port opening (head and outlet). 1.3 Internal casting. Zone 2
31、: Red 2.1 Machined flange seal surfaces (except for Zone 1, Section 1.2) 12 mm zone around each head port opening; 15 mm zone around the outlet opening. (See the part specific drawing for the actual dimensions.) 2.2 Machined boss surfaces EGR, O2, etc. Zone 3: Green 3.1 Machined flange surfaces exce
32、pt for seal surfaces and other machined surfaces that are not in Zones 1 and 2. 3.2 Mounting holes. 3.3 Threaded holes. Table A2: Porosity, Shrink and Inclusion Size and Quantity Limits per Table A1 Width Depth Quantity Zone 1: Blue 1.1 1.2 3.0 mm 1.5 mm 2 per runner, flange or boss Casting disconti
33、nuities 1 mm or less are allowed. 1.3 Internal casting discontinuities limited to ASTM E446 Categories A, B, and C, Severity Level 3. Zone 2: Red 0.5 mm 0.5 mm 3.0 mm minimum between each discontinuity Zone 3: Green 3.1 3.2 3.0 mm 1.5 mm 2 per runner or hole 3.3 1 thread width 1 thread depth 2 per t
34、hreaded hole No casting discontinuities are allowed in the first 2 full threads. Table A3: Depression and Protrusion Size Limits per Table A1 Diameter Height/Depth Quantity Zone 1: Blue Fins, flash 2.0 mm 3.0 mm 2 per runner, flange or boss Depressions, protrusions 10.0 mm 3.0 mm 2 per runner, flang
35、e or boss Gates - 5.0 mm - Blowtube, Chaplet, etc. - 2.0 mm - Zone 2: Red No depressions or protrusions are allowed in this area. Zone 3: Green No depressions or protrusions are allowed in this area. Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
