1、WORLDWIDEENGINEERINGSTANDARDSTest Procedure GMW15468Hydrolytic Resistance of Polyamide to Coolants Copyright 2013 General Motors Company All Rights ReservedMarch 2013 Page 1 of 31 ScopeNote: Nothing in this standard supercedes applicable laws and regulations.Note: In the event of conflict between th
2、e English and domestic language, the English language shall takeprecedence.1.1 Purpose. This standard shall be used to determine the hydrolytic resistance of glass fiber reinforcedpolyamide 66 to the influence of water/coolant mixtures at elevated temperatures.1.2 Foreword. Not applicable.1.3 Applic
3、ability. This standard is particularly suitable for assessing materials intended for use in the enginecooling circuit.2 ReferencesNote: Only the latest approved standards are applicable unless otherwise specified.2.1 External Standards/Specifications.ISO 179-1 ISO 527-1 ISO 527-22.2 GM Standards/Spe
4、cifications.GMW3059 GMW3420 GMW162703 Resources3.1 Facilities.3.1.1 Calibration. The test facilities and equipment shall be in good working order and shall have a validcalibration label.3.1.2 Alternatives. Alternative test facilities and equipment may also be used. However, all measuringvariables as
5、 specified in this standard shall be determined correctly with respect to their physical definition.3.2 Equipment.3.2.1 Autoclave With electronically-controlled electrical heating system or pressure vessels, preferablystainless steel, suitable for use in drying ovens. The dimensions and volume of th
6、e vessels shall be inaccordance with the shape and number of the test pieces to be stored simultaneously in the test fluid.3.2.2 Testing Machines. Testing machines which are equipped in such a manner as to determine thespecified properties according to paragraph 4.3.4.3.2.3 Test Fluid. Mixtures of r
7、adiator anti-freeze agents according to GMW3420 and distilled water shall beused. Unless agreed otherwise, the mixture ratio shall be 1:1 vol. concentrated anti-freeze agents must not beused. Any one of the approved products may be used as a test fluid. The test fluid shall not be changed duringstor
8、age.3.2.4 Desiccator.3.2.5 Cotton Cloth.3.3 Test Vehicle/Test Piece. Polyamide 66 reinforced with glass fibers, with stable hydrolytic heat stabilizeraccording to e.g., GMW16270P PA66-GF30.3.4 Test Time. See Table 1, Table 2 and Table 3.Copyright General Motors Company Provided by IHS under license
9、with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW15468 Copyright 2013 General Motors Company All Rights ReservedMarch 2013 Page 2 of 33.5 Test Required Information. The testing of 1:1 water/antifreeze
10、mixtures at temperatures +108 C(boiling point of the mixture) shall be performed in pressure vessels under increased pressure. Loss ofpressure would lead to a severe delay in the mixtures reaching boiling point. The vessels shall therefore bedesigned for pressure loads and the relevant safety regula
11、tions observed. The pressure vessel shall only beopened once it has cooled down / at room temperature.3.6 Personnel/Skills. Not applicable.4 Procedure4.1 Preparation. For initial sample approval and arbitration purposes, the minimum time period betweenmanufacturing and testing shall be 7 days, for r
12、outine quality control purposes the time period shall beminimum 72 h.Before testing, the test pieces shall be stored at a temperature of (+23 5) C for at least 8 h and shall be freefrom strain during this period.4.2 Conditions.4.2.1 Environmental Conditions. The tests shall be performed on dry as mo
13、lded test specimen according toISO 527-1 and ISO 527-2, where possible Type A.4.2.2 Test Conditions. Deviations from the requirements of this standard shall have been agreed upon. Suchrequirements shall be specified on component drawings, test certificates, reports, etc.4.3 Instructions.4.3.1 Check-
14、in Test. The test according to the properties in paragraph 4.3.4.1 shall be performed without anyfurther pre-treatment.4.3.2 Storage. The test specimen shall be stored in the test medium in the autoclav for the test time and testtemperature according to paragraph 4.3.4.2 and 4.3.4.3 respectively.Aft
15、er test time the test specimens shall be cooled down in the test medium to (+23 5) C.Then the test specimens shall be removed from the test medium, rinsed with water and wiped dry with a cottoncloth.After cleaning the test specimen shall be stored in a desiccator.4.3.3 Test after Storage. Within 7 d
16、ays (maximum) after the storage in the autoclav (paragraph 4.3.2) theproperties according to paragraph 4.3.4.2 and 4.3.4.3 respectively shall be tested.4.3.4 Determination of Properties.Note: The properties are only applied for test specimen (see paragraph 4.2.1) and not for out-of-tool parts.4.3.4.
17、1 Determination of property values of the material in the as-received condition according to Table 1.Table 1: Properties in the as-received condition, dry as molded.Properties Standard UnitStress at Break ISO 527-1 N/mm2Strain at Break ISO 527-1 %Charpy Impact Strength at +23 C ISO 179-1/ 1eU kJ/m24
18、.3.4.2 Determination of property values after (504 /-2) h storage according to Table 2.Table 2: Properties after storage (504 /-2) h at (+130 3) C.Properties Standard UnitStress at Break ISO 527-1 N/mm2Strain at Break ISO 527-1 %Charpy Impact Strength at +23 C ISO 179-1/ 1eU kJ/m2Copyright General M
19、otors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW15468 Copyright 2013 General Motors Company All Rights ReservedMarch 2013 Page 3 of 34.3.4.3 Determination o
20、f property values after (1008 /-2) h storage according to Table 3.Table 3: Properties after storage (1008 -2) h at (+130 3) C.Properties Standard UnitStress at Break ISO 527-1 N/mm2Strain at Break ISO 527-1 %Charpy Impact Strength at +23 C ISO 179-1/ 1eU kJ/m25 Data5.1 Calculations. Not applicable.5
21、.2 Interpretation of Results. The test pieces stored in the test fluid shall be assessed visually to the criteriagiven in the material specification. The properties (see paragraph 4.3.4) shall be measured and checked forcompliance.5.3 Test Documentation. The results of the measurement shall be compi
22、led in a test report with reference tothis Test Procedure.6 SafetyThis standard may involve hazardous materials, operations, and equipment. This standard does not propose toaddress all the safety problems associated with its use. It is the responsibility of the user of this standard toestablish appr
23、opriate safety and health practices and determine the applicability of regulatory limitations priorto use.7 Notes7.1 Glossary.Hydrolytic Resistance: The term hydrolytic resistance refers to the behaviour of materials with regard to theinfluence of water.7.2 Acronyms, Abbreviations, and Symbols. Not
24、applicable.8 Coding SystemThis standard shall be referenced in other documents, drawings, etc., as follows:Test to GMW154689 Release and RevisionsThis standard was originated in October 2006. It was first approved by Global Plastics Team inDecember 2006. It was first published in February 2008.Issue
25、 Publication Date Description (Organization)1 MAY 2007 Initial publication.2 MAR 2008 Was issue 1, date MAY 2007; conversion from Test Procedure to GeneralSpecification; Targets added3 MAR 2013 5 year refresh; converted into new template (Plastics GSSLT)Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
