GM9540P -加速腐蚀试验
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Test Equipment Test Method
3.2.2 Test Samples. Test samplesshall be representativeof productionintent. Samplesize shall be consistentwith durability requirements determined by the appropriate Material/ CorrosionEngineeringdepartment. 4 TEST PROCEDURE. 4.1 COUPON/TESTSAMPLE PREPARATION. 4.1.1 Each coupon shall be permanentlyidentified by stamping numbersonto the surface. 4.1.2 Corrosion coupons can be cleaned with methanol or acetone solution and accurately weighed prior to use. The weight, in milligrams (mg), shall be recordedand retainedfor future reference. NOTE: It is critical that all forming or preservationoils/lubes be removedprior to exposureto allow for general/uniformcorrosion of the coupon. This processcan be aided by using a commercial grade degreaserprior to methanol or acetone clean. 4.2 COUPONRACK PREPARATION. Prior to start of test, preparethe couponrack with sufficient couponsto monitor the
NOTE 1: A cycle is madeup of the daily eventsor test inputs prescribedin Table4. A cycle normally requires 1 day to complete. The testduration is dictatedby the numberof testcycles. NOTE 2: A phaseis madeup of a predetermined number of cycles, 8 cyclesconstitute 1 phase. NOTE 3: The coupon massloss values shown in Table 2 are used to verify that the correct amount of corrosion has been producedby the test, 2 REFERENCED STANDARDS. GM4465P GM9102P GM9508P ASTM B117
6038-6638 63456945 6957-7557 8178-8778
* These massloss values correspondto the test duration requirements listed in Table 1 above and are applicable to the standard test procedure only. Modifications to the test may or may not attaiu equivalent levels of mass loss.
nun 0.79 in A B Test Duration C x D
1.59 3.18 6.35
l/32 l/16 l/8 l/4
8281228 874-1274 9651375 1147-1547
1496-1896 15741974 1731-2131 2043-2443
3210-3810 3378-3978 3712-4312 4379-4979
DECEMBER 1997
PAGE 1
954OP
VND.GM
GM=l54ClP-ENGL
I,997
m
=lllClb37=l
llOl,2L32
Lbll
m
I
GENERAL MOTORS ENGINEERING STANDARDS
I
Materials and Processqs - Procedures
3
EQUIPMENT AND TEST MATERIAL.
3.1 TEST EQUIPMENT. 3.1.1 Fog Humidity Cabinet The humidity cabinet shall be as specified by GM4465P and Table 3. (Waterfog or visible water droplets on parts - continuous after equilibrium is reached.) 3.1.2 Salt Mist Application. The salt mist solution shall be as specified in Table 3. The solution shall be.sprayedas a mist (for example,from a plastic bottle onto the test samplesand coupons).The spray nozzle shall be such that the salt solution is atomizedinto a mist asrequired.A siphon spraypoweredby oil-free regulatedair or a hand operatedpump spray may also be used The quantity of spray applied should be sufficient to rinse away any salt accumulation left from previous sprays. (Test samplesand couponsshall be thoroughly wet/dripping.)
VND.GM
Gtl=l5~UP-ENGL
1997
-
900b379
OOl,2L3l,
228
m
I
GENERAL MOTORS ENGINEERING STANDARDS
I
Materials and PFocesses - Procedures
ACCELERATED CORROSION TEST
GM9540P labo1 SCOPE. This procedure&scribes an accelerated ratory corrosion test method to evaluate assemblies and components.The test procedure provides a combination of cyclic conditions (salt solution, various temperatures, humidity, and ambientenvironment)to accelerate metallic corrosion. The procedure is effectivefor evaluatinga variety of corrosion mechanisms, such as general,galvanic, crevice, etc. The test duration can be individually tailored to achieve any desired level of corrosionexposure. Also, synergisticeffects due to temperature,mechanicaland electrical cycling can be comprehended by this test. See Appendix A for typical modifications. NOTE: Test durationsA and B can be used as both QC tests and validation testsdependingon the purposeof the test. Test durationsC and D or any modified test are to be usedfor validation and developmentpurposes. 1.1 The test method is comprised of 1.25% (0.9% sodium chloride, 0.1% calcium chloride and 0.25% sodium bicarbonate) salt mist applicationscoupled with high temperature and high humidity and moderately high temperature dry off. It requiresa 16 h work day or an automaticcycling test chamber. IMPORTANT: Engineering drawings and material specifications that referencethis test procedure must specify the test duration, (A, B, C or D) or the number of test cycles as indicated in Table 1. (Example, GM954OP. Test Duration B.) In addition, the criteria for making pass/fail determinationsmust be specified.Test durations A and B can be used for quality control and validation proceduresas appropriate.Longer test durations(C and D) and testsinvolving modificationsareto be used for validation purposesonly.
I
ACCELERATED CORROSION TEST
GM9540P 3.1.3 Dryoff Environment. The dryoff environment area shall be maintained with sufficient air circulation to prevent temperaturestratification, and also allow thorough drying of the material. The temperature and humidity conditions are shownin Table 3. TABLE 3 - TEST PARAMETERS
TABLE 1 - CYCLES (APPROXIMATE) FOR TARGET MASS LOSS
‘I&t Duration A B C D
Test Method CouponsRequired (mm>
Biblioteka Baidu
8 Cycles 2
16 Cycles 4
40 Cycles 10
80 Cycles 20
TABLE 2 - MASS LOSS TARGET RANGES, mg*(AT THE END OF TEST) Initial coupon Thickness
3.2.2 Test Samples. Test samplesshall be representativeof productionintent. Samplesize shall be consistentwith durability requirements determined by the appropriate Material/ CorrosionEngineeringdepartment. 4 TEST PROCEDURE. 4.1 COUPON/TESTSAMPLE PREPARATION. 4.1.1 Each coupon shall be permanentlyidentified by stamping numbersonto the surface. 4.1.2 Corrosion coupons can be cleaned with methanol or acetone solution and accurately weighed prior to use. The weight, in milligrams (mg), shall be recordedand retainedfor future reference. NOTE: It is critical that all forming or preservationoils/lubes be removedprior to exposureto allow for general/uniformcorrosion of the coupon. This processcan be aided by using a commercial grade degreaserprior to methanol or acetone clean. 4.2 COUPONRACK PREPARATION. Prior to start of test, preparethe couponrack with sufficient couponsto monitor the
NOTE 1: A cycle is madeup of the daily eventsor test inputs prescribedin Table4. A cycle normally requires 1 day to complete. The testduration is dictatedby the numberof testcycles. NOTE 2: A phaseis madeup of a predetermined number of cycles, 8 cyclesconstitute 1 phase. NOTE 3: The coupon massloss values shown in Table 2 are used to verify that the correct amount of corrosion has been producedby the test, 2 REFERENCED STANDARDS. GM4465P GM9102P GM9508P ASTM B117
6038-6638 63456945 6957-7557 8178-8778
* These massloss values correspondto the test duration requirements listed in Table 1 above and are applicable to the standard test procedure only. Modifications to the test may or may not attaiu equivalent levels of mass loss.
nun 0.79 in A B Test Duration C x D
1.59 3.18 6.35
l/32 l/16 l/8 l/4
8281228 874-1274 9651375 1147-1547
1496-1896 15741974 1731-2131 2043-2443
3210-3810 3378-3978 3712-4312 4379-4979
DECEMBER 1997
PAGE 1
954OP
VND.GM
GM=l54ClP-ENGL
I,997
m
=lllClb37=l
llOl,2L32
Lbll
m
I
GENERAL MOTORS ENGINEERING STANDARDS
I
Materials and Processqs - Procedures
3
EQUIPMENT AND TEST MATERIAL.
3.1 TEST EQUIPMENT. 3.1.1 Fog Humidity Cabinet The humidity cabinet shall be as specified by GM4465P and Table 3. (Waterfog or visible water droplets on parts - continuous after equilibrium is reached.) 3.1.2 Salt Mist Application. The salt mist solution shall be as specified in Table 3. The solution shall be.sprayedas a mist (for example,from a plastic bottle onto the test samplesand coupons).The spray nozzle shall be such that the salt solution is atomizedinto a mist asrequired.A siphon spraypoweredby oil-free regulatedair or a hand operatedpump spray may also be used The quantity of spray applied should be sufficient to rinse away any salt accumulation left from previous sprays. (Test samplesand couponsshall be thoroughly wet/dripping.)
VND.GM
Gtl=l5~UP-ENGL
1997
-
900b379
OOl,2L3l,
228
m
I
GENERAL MOTORS ENGINEERING STANDARDS
I
Materials and PFocesses - Procedures
ACCELERATED CORROSION TEST
GM9540P labo1 SCOPE. This procedure&scribes an accelerated ratory corrosion test method to evaluate assemblies and components.The test procedure provides a combination of cyclic conditions (salt solution, various temperatures, humidity, and ambientenvironment)to accelerate metallic corrosion. The procedure is effectivefor evaluatinga variety of corrosion mechanisms, such as general,galvanic, crevice, etc. The test duration can be individually tailored to achieve any desired level of corrosionexposure. Also, synergisticeffects due to temperature,mechanicaland electrical cycling can be comprehended by this test. See Appendix A for typical modifications. NOTE: Test durationsA and B can be used as both QC tests and validation testsdependingon the purposeof the test. Test durationsC and D or any modified test are to be usedfor validation and developmentpurposes. 1.1 The test method is comprised of 1.25% (0.9% sodium chloride, 0.1% calcium chloride and 0.25% sodium bicarbonate) salt mist applicationscoupled with high temperature and high humidity and moderately high temperature dry off. It requiresa 16 h work day or an automaticcycling test chamber. IMPORTANT: Engineering drawings and material specifications that referencethis test procedure must specify the test duration, (A, B, C or D) or the number of test cycles as indicated in Table 1. (Example, GM954OP. Test Duration B.) In addition, the criteria for making pass/fail determinationsmust be specified.Test durations A and B can be used for quality control and validation proceduresas appropriate.Longer test durations(C and D) and testsinvolving modificationsareto be used for validation purposesonly.
I
ACCELERATED CORROSION TEST
GM9540P 3.1.3 Dryoff Environment. The dryoff environment area shall be maintained with sufficient air circulation to prevent temperaturestratification, and also allow thorough drying of the material. The temperature and humidity conditions are shownin Table 3. TABLE 3 - TEST PARAMETERS
TABLE 1 - CYCLES (APPROXIMATE) FOR TARGET MASS LOSS
‘I&t Duration A B C D
Test Method CouponsRequired (mm>
Biblioteka Baidu
8 Cycles 2
16 Cycles 4
40 Cycles 10
80 Cycles 20
TABLE 2 - MASS LOSS TARGET RANGES, mg*(AT THE END OF TEST) Initial coupon Thickness