1、 WORLDWIDE ENGINEERING STANDARDS General Specification GMW16718 Front and Rear Knuckles Copyright 2012 General Motors Company All Rights Reserved June 2012 Originating Department: North American Engineering Standards Page 1 of 29 1 Introduction Note: Nothing in this standard supercedes applicable la
2、ws and regulations. Note: In the event of conflict between the English and domestic language, the English language shall take precedence. 1.1 Scope. This specification defines the general Material performance and requirements for Cast or Forged knuckles. The Statement of Requirements (SOR) and the A
3、ppendix F10 Material Requirements supercede any requirements stated in this standard. 1.2 Mission/Theme. This document describes the material related knuckle component specifications. It includes requirements that are to guarantee the quality of both the material and the knuckle. It serves as an acc
4、eptance standard for the inspection of internal and surface anomalies and discontinuities. 1.3 Classification. Not applicable. 2 References Note: Only the latest approved standards are applicable unless otherwise specified. 2.1 External Standards/Specifications. ASTM A275 ASTM B594 ASTM E446 ISO 650
5、6/ASTM E10 ASTM A897 ASTM E155/E2422 ASTM E1025 SAE 1541 ASTM A909 ASTM E165/E1417 ASNT SNT-TC-1A 2.2 GM Standards/Specifications. GMW5 GMW15181 GMW15536 GMW16705 GMW10 GMW15182 GMW15657 GMW3059 GMW15183 GMW16436 GMW14988 GMW15426 GMW16704 3 Test Preparation and Evaluation 3.1 Resources. 3.1.1 Calib
6、ration. The test facilities and equipment shall be in good working order and shall have a valid calibration label. 3.1.2 Alternatives. Alternative test facilities and equipment may also be used. However, all measuring variables as specified in this standard shall be determined correctly with respect
7、 to their physical definition. 3.1.3 Facilities. The evaluation of porosity on machined surfaces, and handling damage will be visually checked. Optical magnifying equipment may be used in visual inspection. The evaluation of internal casting porosity where required, will be performed on all castings
8、 by real time/digital x-ray. The evaluation of surface cracking where required will be evaluated via fluorescent die penetrant (aluminum) and magnetic particle (iron) on all knuckles. 3.1.4 Equipment. Visual evaluation systems, real time x-ray system, testing equipment for cracks, Microstructure eva
9、luation and Nondestructive Test (NDT) equipment. 3.1.5 Test Vehicle/Test Piece. Test parts shall be selected per GMW16704. Excised mechanical testing samples shall be of sufficient size to provide standard test specimens per GMW16705 requirements. Copyright General Motors Company Provided by IHS und
10、er license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW16718 Copyright 2012 General Motors Company All Rights Reserved June 2012 Page 2 of 29 3.1.6 Test Time. Not applicable. 3.1.7 Test Required I
11、nformation. As stated in Appendix A. 3.1.8 Personnel/Skills. Personnel making accept/reject decisions based on the results of nondestructive testing performed shall be fully trained and certified in appropriate disciplines per American Society for Nondestructive Testing Recommended Practice No.SNT T
12、C 1A (ASNT SNT-TC-1A). 3.2 Preparation. A detailed test matrix shall be prepared prior to all tests. All sample preparation shall be carried out with due care to eliminate any effects (stress, deformation, heating, corrosion, etc.,) on the material or part that may cause erroneous results. 3.2.1 Tes
13、t Samples for Material Strength. Test Samples shall be taken from unmachined knuckles in the finished form (i.e., after any heat treatment or thermal processing). If heat treated Aluminium knuckles are painted with a baked paint process, then this baking treatment shall be performed prior to test sa
14、mples being taken. 3.3 Conditions. The finished surfaces shall be dry and free of dirt, dust and rust. 3.3.1 Environmental Conditions. Parts and specimens shall be allowed to stabilize to room temperature prior to test. 3.3.2 Test Conditions. Deviations from the requirements of this standard shall h
15、ave been agreed upon. Such requirements shall be specified on component drawings, test certificates, reports, etc. 3.4 Instructions. As per section 4 and GMW16705. 3.5 Data. As per Appendix A and GMW16705. 3.6 Safety. This standard may involve hazardous materials, operations, and equipment. This sta
16、ndard does not propose to address all the safety problems associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. 3.7 Documentation. Samples of componen
17、ts or material released to this standard shall be tested for conformity with the requirements of this standard and approved by the responsible GM Department prior to the start of delivery of production level components or materials. Any change to the component or material, e.g., design, function, pr
18、operties, manufacturing process and/or location of manufacture requires a new release of the product. It is the sole responsibility of the supplier to provide the customer, unsolicited, with documentation of any change or modification to the product/process, and to apply for a new release. If not ot
19、herwise agreed to, the entire verification test shall be repeated and documented by the supplier prior to start of delivery of the modified or changed product. In some cases, a shorter test can be agreed to between the responsible GM department and the supplier. 3.7.1 Test Results. As per Appendix A
20、. 4 Requirements and Procedure The supplier is responsible to furnish part specific drawings with all agreed upon material, quality and other requirements prior to Production Part Approval Process (PPAP). A matrix summarizing some of the knuckle testing requirements is listed in Appendix A. 4.1 Mate
21、rial Specification. The material specification shall be listed on the Math model and should fall within a material group listed in Table 1. The specific grades of materials listed in Table 1 are not exhaustive and alternative materials may be used after agreement between Supplier and GM Engineering.
22、 When an alternative material is used, then the requirements of the relative category are still required to be fulfilled. Table 1: Material Groupings of Some Common Knuckle Materials Material Group Typical Material Specifications for Each Group Aluminium Casting GMW5M-Al-C-P-Si7Mg-T6 - Nodular Iron
23、Casting GMW10M-IR-C-N450-xx ADI to ASTM A897 Grade 900/650/09 Aluminium Forging GMW15657M-AL-F-Mg1SiCu(AA 6061)-T6 GMW15657M-AL-F-Si1MgMn(AA 6082)-T6 Steel Forging ASTM A909 Grade 5 SAE 1541 Modified ADI = Austempered Ductile Iron Copyright General Motors Company Provided by IHS under license with G
24、eneral Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW16718 Copyright 2012 General Motors Company All Rights Reserved June 2012 Page 3 of 29 4.1.1 Mechanical Properties. Mechanical Properties shall be tested on s
25、amples machined from knuckles as per Appendix B. Mechanical Properties shall be per: GMW16704 Class 1, with limits set as per Table 2. If the exact material grade is not listed in Table 2 then the mechanical properties must be per: GMW16704 Class 1, with the specific properties listed in the Math Mo
26、del. A component level fatigue testing may be used in lieu of material fatigue testing if agreed upon by the responsible GM department and the supplier. 4.1.1.1 Hardness. Hardness measurements shall be taken from samples that are evenly distributed throughout the heat treatment (HT) batches or conti
27、nuous cycles for heat treated parts. For non-heat treated parts, hardness measurements shall be taken from samples that are evenly distributed throughout the casting batch. 4.1.1.2 Fatigue. Fatigue testing shall be performed on samples from same heat/batch as tensile testing. 4.1.2 Chemical Composit
28、ion. The Material Specification shall be listed on the Math Model, along with any deviations. GMW5 for Aluminum Castings, GMW15657 for Aluminum Forgings and GMW10 for Nodular Iron are applicable GM standards. For Austempered Ductile Iron Castings and Steel forgings, ASTM standards are applicable. 4.
29、1.2.1 Nodular Iron Castings. Silicon composition shall be below 2.80% for optimum low temperature properties. 4.1.2.2 Aluminium Castings. It is recommended that at least 50% of the charge is to be made up of virgin Aluminium. It is also recommended to restrict Iron composition to a maximum of 0.12%
30、to meet the required mechanical properties. 4.1.2.3 Aluminium Forgings. No additional chemical requirements. 4.1.2.4 Steel Forgings. No additional chemical requirements. 4.1.3 Ultrasonic Testing of Aluminum Forging Base Material. Forging base stock shall be tested for flaws ultrasonically on 100% of
31、 logs. Testing shall be performed in 2 directions, at right angles to each other. 4.1.4 Microstructure. Microstructures shall be regularly monitored at sampling rates that meet or exceed those specified in Appendix A. 4.1.4.1 Aluminium Castings. The microstructure shall consist of a fine-grained, we
32、ll rounded, Al-Si-Eutectic in an aluminum -Matrix (Continuous Phase). Dendrite Arm Spacing (DAS) to be less than 70 m within 10 mm of the surface. Dendrite Arm Spacing (DAS) measurement per GMW16436. 4.1.4.2 Nodular Iron Castings (Including ADI). Nodularity should be checked at the thickest section
33、of the casting. Automated sonic or ultra sonic methods shall be used to verify nodularity on 100% of parts. Chills should be checked in thinnest sections. Pearlite and Carbide levels shall be regularly monitored at sampling rates that meet or exceed those specified in Appendix A. 4.1.4.3 Aluminium F
34、orging. The microstructure shall be primarily fibrous with minimum recrystallized grains. 4.1.4.4 Steel Forging. No additional microstructural requirements. Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted
35、 without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW16718 Copyright 2012 General Motors Company All Rights Reserved June 2012 Page 4 of 29 Table 2: Mechanical Properties as per GMW16704-Class 1 Material Grade Hardness (HBW) Per ISO 6506/ ASTM E10 B1 YS (MPa) Min. YS (MPa) B1 UTS (MPa
36、) Min. UTS (MPa) Min. El (%) Fatigue/OP 100% STP B1 (MPa) GMW5M-Al-C-P-Si7Mg-T6-210 90 Note1 85 Note 2 210 210 290 290 8 100 GMW5M-Al-C-P-Si7Mg-T6a -190 85 Note1 80 Note 2 190 190 270 270 7 95 GMW15657M-AL-F-Mg1SiCu-T6 (AA 6061-T6) 100 Note1 95 Note 2 270 270 310 310 10 125 GMW15657M-AL-F-Si1MgMn(AA
37、 6082)-T6 100 Note1 95 Note 2 310 310 340 340 10 135 GMW10M-IR-C-N450-12 156 to 197 Note 3 310 310 450 450 12 NA GMW10M-IR-C-N450-10 156 to 197 Note 3 290 290 450 450 10 NA ADI ASTM A897 Grade 900/650/09 269 to 341Note 3 650 650 900 900 9 NA SAE 1541 Modified 262 to 302 Note 3 - 685 - 830 18 NA ASTM
38、 A909 Grade 5 229 to 285 Note 3 - 550 - 690 15 NA Min. = Minimum Note 1: 10 mm diameter ball, 1000 kg force, 10 to 15 seconds (or equivalent) Note 2: 10 mm diameter ball, 500 kg force, 10 to 15 seconds (or equivalent) Note 3: 10 mm diameter ball, 3000 kg force, 10 to 15 seconds (or equivalent). 4.1.
39、5 Heat Treatment. All heat treatment equipment shall be well maintained and have regular calibration checks. Due care shall be taken to fully account for any thermal gradients present in the equipment. No repeat heat treatment may be performed without approval of GM Materials Engineering. Approval m
40、ay require increased sampling rates and additional validation testing. 4.2 Inspection Requirements. 4.2.1 Visual Inspection by Casting/Forging Supplier. A 100% visual inspection will be performed by the supplier for any surface anomalies or discontinuities including (but not limited to) cracks, blis
41、ters, laminations, die coating concerns, pin holes, handling damage and locator issues on all surfaces. Section 4.2.7 details some minimum acceptance standards. 4.2.2 Inspection of Machined Surfaces. The machinist will inspect the knuckles after machining for any anomalies or discontinuities (especi
42、ally porosity). Section 4.2.7 details some minimum acceptance standards. 4.2.3 Real Time X-ray Inspection of Castings. 4.2.3.1 Real Time X-ray Testing Equipment Capability. The x-ray equipment shall be capable of inspecting to a 2-3T (2% of 3 times the thickness) penetrometer referenced in ASTM E102
43、5. The supplier will assure equipment capability to detect discontinuities 4% of material thickness across the view axis. The detection limit of inspection system will assure discontinuities 6% are identified and evaluated to the specification limits, an example of regional breakdowns is shown in Ap
44、pendix C. The equipment must be capable of capturing images and the image retention period must be agreed by GM Engineering. 4.2.3.2 Cast Knuckle Development. Hard film X-rays or digitally recorded x-rays must be taken of all cast knuckles used in durability tests. Whenever possible, Knuckles should
45、 be selected for these tests that contain the worst case anomalies expected during production. Different maximum levels of anomalies may be allocated into different zones through testing and analysis as per Section 4.2.7. The final allowable anomaly levels and zones will be based on what was validat
46、ed in component durability testing and shall be agreed upon by GM Engineering and the supplier and recorded in the GM part drawing. Unless otherwise agreed upon, the maximum anomaly level that should be agreed upon and validated is shown in Table 3. Copyright General Motors Company Provided by IHS u
47、nder license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW16718 Copyright 2012 General Motors Company All Rights Reserved June 2012 Page 5 of 29 Table 3: Maximum Internal Discontinuity Size If no a
48、nomaly was present in validation samples, then no anomaly is allowed in production. Material Group Maximum Permissible Size (or Level) Red Zone Blue Zone Cast Aluminium ASTM E155/E2422, Porosity and Shrinkage Level 1 ASTM E155/E2422, Porosity and Shrinkage Level 2 Nodular Iron ASTM E446, Porosity an
49、d Shrinkage Level 1 ASTM E446, Porosity and Shrinkage Level 2 4.2.3.3 Cast Knuckle Production. The level of porosity (shrinkage or gas types) shall not exceed the agreed upon levels based on durability tested samples. The evaluation of internal porosity shall be performed on 100% of all Aluminium castings using X-ray imaging or fluoroscopy. 4.2.4 Magnetic Particle or Fluorescent Dye Penetrant Inspection. Fluorescent dye penetrant inspection
