1、GM DAEWOO Auto & Technology EDS Engineering, GM DAEWOO Auto & Technology Standards METHOD OF LIQUID PENETRANT TEST EDS-T-7124 ISSUED DATE: 1988. 11. 10 REVISED DATE: 2006. 06. 19 VERSION: 2 EDS-T-7124EXPANDING TEST FOR TUBES PAGE: 1/9 ISSUED DATE: 1988. 11. 10 REVISED DATE: 2006. 06. 19 VERSION: 2 G
2、M DAEWOO Auto & Technology 1. SCOPE This standard specifies liquid penetrant testing (hereinafter referred to as test) for metallic materials such as ferrous and nonferrous metal and non-metallic materials such as plastic, glass, ceramic and its product(hereinafter referred to as test piece). 2. DEF
3、INITIONS 2.1. Emulsifier: Substances which help penetrant washed with water, acting with unwashable penetrant such as oil 2.2. Water washable penetrant: A type of penetrant to be washed with water due to its inclusion of emulsifier. 2.3. Penetrant sensitivity: Performance of penetrant from penetrati
4、on until it indicates flaws after being developed. 2.4. Application of penetrant: Applying an inspection material to the surface of test piece by dipping, brushing, spraying or any other method. 2.5. Penetrant application time: Time during which a kind of inspection material on the surface of the pi
5、ece continues to be kept in a liquid condition without being dried. 2.6. Ultraviolet rays: Ultraviolet rays with a wave length of 3,200 4,000 which passed through filtering device. 2.7. Fluorescent: Visible ray which a chemical gives off under ultraviolet rays. 2.8. Developer: Substance which helps
6、the pattern of flaws be recognized under ultraviolet rays or natural light by absorbing or siphoning off penetrant liquid which has penetrated into surface cracks or flaws. 3. QUALIFICATION OF TEST PERSONNEL Test personnel shall be the one who has necessary qualifications (non-destructive test engin
7、eer) or sufficient knowledge and experience in this field. 4. MATERIAL 4.1. Selection of material Unless otherwise specified, all the inspection materials such as penetrant, emulsifier, and developer shall be the ones which come up to the international standard and shall not be harmful to human body
8、 and shall be suitable for each test method. 4.2. Guidance for use Application time of emulsifier, and concentration and mixing procedure of wet developer shall conform to the manufacturers order. EDS-T-7124EXPANDING TEST FOR TUBES PAGE: 2/9 ISSUED DATE: 1988. 11. 10 REVISED DATE: 2006. 06. 19 VERSI
9、ON: 2 GM DAEWOO Auto & Technology 4.3. Check The sensitivity of penetrant in use within tank shall be checked at least per month, by comparing it with that of standard penetrant. Check by comparing indication degrees with each other after dipping the test pieces having already known flaws into both
10、penetrants respectively and then developing them under the same condition. If pollution, decrease in penetrability or in fluorescency is found in penetrant is use, this penetrant liquid shall be disposed. 4.4. Preservation 4.4.1. Penetrant and emulsifier Penetrant and emulsifier never fail to keep t
11、he cap closed when in disuse to prevent entering of dusts or vaporizing of moisture. When in use, parts drenched with moisture shall not be recklessly dipped into penetrant or emulsifier. 4.4.2. Developer Care shall be taken lest dry developer should form into lumps in case of long-term preservation
12、 or should be filled with moisture. Spray type developer shall be preserved in cold and dark place as sealed. 5. PROCESS 5.1. Classification Penetrant tests are classified as follows. Type - Fluorescent penetrant A - Water-washable B - Post-emulsifiable C - Solvent-removable Type - Dye penetrant A -
13、 Water-washable B - Post-emulsifiable C - Solvent-removable 5.2. Selection of test method Personnel who designs item requiring test shall specify the type and method of the test in drawings or specification and determine the evaluation standard with the size of flaws or its density. Unless otherwise
14、 specified, test personnel shall perform the test with the most appropriate method. EDS-T-7124EXPANDING TEST FOR TUBES PAGE: 3/9 ISSUED DATE: 1988. 11. 10 REVISED DATE: 2006. 06. 19 VERSION: 2 GM DAEWOO Auto & Technology Table 1. Application Method Object I-A I-B I-C II-A II-B II-C Fine flaw, wide a
15、nd shallow flaw O (O) Fatigue crack, work crack, small flaw in width O O (O) Small mass production part, part with sharp angle such as screw and key hole, etc. O O Test piece with rough side O O O O Partial inspection test for large part or structure O O In case there is no water supply nor electric
16、ity equipments O In case it is difficult to darken the test equipments O O O EDS-T-7124EXPANDING TEST FOR TUBES PAGE: 4/9 ISSUED DATE: 1988. 11. 10 REVISED DATE: 2006. 06. 19 VERSION: 2 GM DAEWOO Auto & Technology Figure 1. Fluorescent Penetrant Processes (Type 1) 5.3. Cleaning Prior to the applicat
17、ion of penetrant for the surface of test piece, substances adhering to surface such as rusts, dirt, fats and oils, paints and unnecessary scales and other pollutants shall be removed clearly to help penetrant enter into all the flaws. EDS-T-7124EXPANDING TEST FOR TUBES PAGE: 5/9 ISSUED DATE: 1988. 1
18、1. 10 REVISED DATE: 2006. 06. 19 VERSION: 2 GM DAEWOO Auto & Technology 5.3.1. Pretreatment with blast method shall not be performed when it is feared that surface stimulation may occur due to shot blast or surface flaws may be sealed. 5.3.2. Paints shall be removed with chemicals rather than physic
19、al method. 5.3.3. All the detergents remaining on the test surface affect the fluorescency of penetrant and therefore, prior to application of penetrant, all the test piece shall be thoroughly dried after being washed off through neutralizing. 5.3.4. Metallic powders which might be in flaw part of s
20、oft metallic parts machined shall be etched. 5.3.5. In case cleaning plastic products, solvent which might affect material quality shall not be used. 5.4. Application of penetrant Penetrant shall be applied to the entire surface of the test part of the test piece whose cleaning is completely finishe
21、d by dipping, spraying or brushing. 5.4.1. Application method shall be selected according to shape and dimensions of test piece, but if possible, dipping shall be used. 5.4.2. The penetration time shall be determined according to material of test piece, processing method, kind of flaws and the kind
22、of penetrant(Refer to Table 2). 5.4.3. For parts whose penetration degree is doubtful, it may be better to apply penetrant longer or again to ensure indication degree of flaws. 5.4.4. To improve the penetration and sensitivity of penetrant, it may be better to preheat the penetrant at 65 max. prior
23、to the application of penetrant. EDS-T-7124EXPANDING TEST FOR TUBES PAGE: 6/9 ISSUED DATE: 1988. 11. 10 REVISED DATE: 2006. 06. 19 VERSION: 2 GM DAEWOO Auto & Technology 2. Liquid Penetrant Penetration Time (Typical) MATERIAL FORM TYPE OF DISCONTINUITY TYPES & PROCESS (A) WATER-WASHABLE PENETRATION
24、TIME* TYPES & PROCESS (B) POST-EMULSIFIED PENETRATION TIME* TYPES & PROCESS (C) SOLVENT-REMOVABLE PENETRATION TIME* ALUMINUM CASTINGS EXTRUSIONS & FORGINGS WELDS ALL ALL POROSITY COLD SHUTS LAPS LACK OF FUSION POROSITY CRACKS FATIGUE CRACKS 5 TO 10 MIN. 5 TO 15 NR* 30 30 30 NR *5 MIN. *5 10 5 5 10 3
25、0 3 3 7 3 3 5 5 MAGNESIUM CASTINGS EXTRUSIONS & FORGINGS WELDS ALL ALL POROSITY COLD SHUTS LAPS LACK OF FUSION POROSITY CRACKS FATIGUE CRACKS 15 15 NR* 30 30 30 NR* 5 5 10 10 10 10 30 3 3 7 5 5 5 7 STEEL CASTINGS EXTRUSIONS & FORGINGS WELDS ALL ALL POROSITY COLD SHUTS LAPS LACK OF FUSION POROSITY CR
26、ACKS FATIGUE CRACKS 30 30 NR* 60 60 30 NR *10 *10 10 20 20 20 30 5 7 7 7 7 7 10 BRASS & BRONZE CASTINGS EXTRUSIONS & FORGINGS WELDS ALL ALL POROSITY COLD SHUTS LAPS LACK OF FUSION POROSITY CRACKS FATIGUE CRACKS 10 10 NR* 15 15 30 5 TO 30 *5 *5 10 10 10 10 5 3 3 7 3 3 3 5 GLASS ALL CRACKS 5 TO 30 5 5
27、 CARBIDE-TIPPED TOOLS LACK OF FUSION POROSITY CRACKS 30 30 30 5 5 20 3 3 5 TITANIUM & HIGH TEMP. ALLOYS ALL NR* 20 TO 30 15 ALL METALS ALL STRESS OR INTER-GRANULAR CORROSION NR* 240 240 * FOR PARTS HAVING A TEMPERATURE OF 60F OR HIGHER * PRECISION CASTINGS ONLY * NR - NOT RECOMMENDED EDS-T-7124EXPAN
28、DING TEST FOR TUBES PAGE: 7/9 ISSUED DATE: 1988. 11. 10 REVISED DATE: 2006. 06. 19 VERSION: 2 GM DAEWOO Auto & Technology 5.5. Removal of penetrant 5.5.1. Water-washable method Penetrant shall be removed with pressure spraying method, if possible. Distance between spray nozzle and the surface of the
29、 test piece shall be about 30cm. The appropriate temperature of cleaning water shall be within 1638. In case of fluorescent penetrant, cleaning shall be carried out with ultraviolet rays, making sure the cleaning conditions. Take care lest penetrant which penetrated into flaws should be washed outsi
30、de due to excessive cleaning. 5.5.2. Post-emulsifiable method (1) In case of Type (fluorescent penetration), the emulsifier application time shall be adjusted, taking into consideration the sensitivity of penetrant, the surface roughness of test piece, activity of emulsifier according to the kind of
31、 flaws to be found for each part. Emulsifier shall be applied with the method which is capable of covering swiftly the entire surface stained with penetrant, such as dipping and spraying, but not brushing. Make the cleaning time as short as possible, not to exceed 5 minutes because it is feared that
32、 penetrant which penetrated into flaw part may be washed outside when the cleaning time lasts long. (2) In case of Type (dye penetrant), other conditions than emulsifier application time shall be the same as those of I type. Emulsifier application time shall be made as short as possible, taking more
33、 careful attention to it than that of I type. After emulsifier application time is up, the entire surface shall be sprayed with water or dipped into water lest emulsification should continue any longer. At this time be careful lest water drop should enter into emulsification tank which is near. It t
34、his case, cleaning method shall be the same as water washable method in item 5.5.1. 5.5.3. Solvent-removable method After applying solvent, excessive penetrant shall be wiped out with dry cloth, regardless of type and . Aerosol type detergent shall not be directly sprayed to the surface of test piec
35、e because it is feared that penetrant which penetrated into fine flaws may be washed outside. 5.6. Developing The work of making the size of flaws appear magnified several times or tens times by spraying developer of white powder on the surface of the test piece and then siphoning remaining penetran
36、t inside flaws out to the surface through capillarity. 5.6.1. Water wet developer The concentration and mixing method of wet developer which is used in the mixture of water and developer powder along with moisturizing compound shall conform to the manufacturers order. Developing method is generally
37、as follows remove the penetrant and then apply developer by the method such as dipping and dry by letting excessive developer flow and drop. To get high sensitivity, dry the part with the heat of the part itself by means of spraying developer after drying the test sample in a hot chamber at an appro
38、priate temperature after the removal of penetrant. EDS-T-7124EXPANDING TEST FOR TUBES PAGE: 8/9 ISSUED DATE: 1988. 11. 10 REVISED DATE: 2006. 06. 19 VERSION: 2 GM DAEWOO Auto & Technology 5.6.2. Volatile wet developer Volatile wet developer made by suspending developer powder into volatile solvent h
39、as comparatively high sensitivity and is used when test piece to be is used without heating it or partial inspection of large parts is performed. 5.6.3. Dry developer After removing penetrant and then drying the part, apply dry developer of fine powder by means of spraying or dipping. Remove excessi
40、ve developer powder by slightly tapping or blowing with an air of low pressure after the application of developer. Dry developer has low sensitivity compared with wet developer. 5.6.4. Drying After the application of wet developer or remove of penetrant, dry the test piece in a hot chamber kept at 6
41、6107 prior to the application of dry developer. Note: ASTM: Drying temperature(Fluorescency: 7993, Dyeing: 7193) 5.7. Inspection The application time of developer shall be determined according to kinds of penetrant, developer and flaws. Generally, developing time shall be the longer one between half
42、 of penetration time and 4 minutes. The sufficient time shall be alloted that indication of flaws may form but inspection shall be conducted before indications of flaws blur due to excessive developing by leaving the test piece too long in the developer. Inspection shall be performed under light con
43、ditions which help manifest indications of flaws. In case inspecting with ultraviolet ray in the dark, it shall be performed after adapting the eyes of test personnel to darkness. In case inspecting with ultraviolet ray, illumination of ultraviolet ray on the surface of test piece shall be 969 LUX(9
44、0 FOOT-CANDLE) min In case of type I(fluorescent penetrant test), 8), pay attention lest flurescent substances and other pollutant should be attached. 6. RECORD OF TEST RESULT In case of occurring the indication of flaws, describe its location and depth in the report or take picture of it with film
45、sensitive to ultraviolet ray in case of type I or copy indication of flaws with scotch tape in case of type II. 7. CAUTIONS Test personnel shall apply this test method after giving enough thought to the merits and demerits of this method, when required, use other non-destructive test method along wi
46、th this or check the presence of flaws by performing destructive test. 7.1. Merit 7.1.1. This can be applied to non magnetic material. 7.1.2. Complex shaped material can be tested. 7.1.3. Circular shape flaws and flaws of every direction can be detected. EDS-T-7124EXPANDING TEST FOR TUBES PAGE: 9/9
47、ISSUED DATE: 1988. 11. 10 REVISED DATE: 2006. 06. 19 VERSION: 2 GM DAEWOO Auto & Technology 7.1.4. Work is easy to perform. 7.1.5. Training of test personnel is easy. 7.1.6. High sensitivity 7.1.7. Portable 7.2. Demerit 7.2.1. Detection of flaws is limited to the surface. 7.2.2. Preparation for surface is required. 7.2.3. Depending on the skill of test personnel 7.2.4. This standard can be applied only to non porous material. 7.2.5. Limited by weather 7.2.6. Harmful to human body
