无损检测磁粉检验工艺设计规程

1、.* Co.,Ltd.焊缝检验规程3Rev.:0Page:1 of 7Title: PROCEDURE FOR MAGNETIC PARTICLE EXAMINATIONPROCEDURE FOR MAGNETIC PARTICLE EXAMINATION磁 粉 检验操 作 工艺规程 CONTROLLED 在控本 UNCONTROLLED 非在控本 COPY NO副本PREPARED BY DATE 日期：REVIEWED BY DATE 日期：APPROVED BY DATE 日期：* Co.,Ltd.焊缝检验规程3Rev.:0Page:2 of 7Title: PROCEDURE FOR

2、MAGNETIC PARTICLE EXAMINATIONDEMONSTRATION CERTIFICATIONThis is to certify that this procedure has been demonstrated on a test specimen with known defects to the satisfaction of the Authorized Inspector according to T-150 of ASME Code Section V, as required by Appendix 6 of Section Div.1. Test Speci

3、men No.: Demo. Report No.: NDE Level : AI: * Co.,Ltd.焊缝检验规程3Rev.:0Page:3of 7Title: PROCEDURE FOR MAGNETIC PARTICLE EXAMINATION 1. General 1.1 This procedure is applied to the magnetic particle examination of ferromagnetic materials and welds for ASME Code items. 1.2 The magnetic particle examination

4、 method is suitable for detecting cracks and other discontinuities on or near the surface in ferromagnetic materials. 1.3 This procedure is applied to wet continuous magnetization by yoke, which shall only be applied to detect discontinuities that are open to the surface of the part. 1.4 This proced

5、ure shall be demonstrated to the satisfaction of the AI prior to implementation. 2. Personnel 2.1 The NDE personnel who engage in magnetic particle examination shall be qualified and certified according to * Co.,Ltd.s “Written Practice for NDE Personnel Training, Examination, Qualification & Cer

6、tification(No.:QCD-011). 3. Description of Method3.1 In principle, the magnetic particle examination method involves magnetizing an area to be examined, and applying ferromagnetic particles to the surface. The particles will form patterms on the surface where cracks or other discontinuties cause dis

7、tortions in the normal magnetic field. These patterns are usually characteristic of the type of discontinuity that is detected. 3.2 The sensitivity of the magnetic particle examination is greatest for surface discontinuities and diminishes rapidly with increasing depth of discontinuities below the s

8、urface. Therefore, this method can only be used for detecting the discontinuities on or near the surface of the material or parts to be tested. 4. Magnetization Equipment and Calibration 4.1 The MT equipment to be used is Yoke, with Type CDX-4. 4.2 Calibration of Equipment4.2.1 Frequency of calibrat

9、ion: Each Magnetizing Equipment with an ammeter shall be calibrated at least once a year，or whenever the equipment has been subjected to a major electric repair, periodic overhaul or damage. If equipment has not been in use for a year or more, calibratioon shall be done prior to first use.4.2.2 Cali

10、bration for lifting power of the Yoke The lifting power will be calibrated with the methods of lifting a standard weight cake. Each alternating-current electromagnetic yoke shall have a lifting power of at least 10lb(44N). at the maximum pole spacing. Each direct-current electromagnetic yoke shall h

11、ave a lifting power of at least 40lb(177N). at the maximum pole spacing. 5. Examination Medium 5.1 The examination medium shall be the finely divided 1.概述 1.1 本规程适用 于ASME规X产品铁磁性材料和焊缝的磁粉检验。 1.2 磁粉检验方法适用于在铁磁性材料外表或其附近探测裂纹和其它不均匀性缺陷。 1.3 本规程适用于磁轭湿粉连续磁化法技术。此法仅适用于检出工件外表开口缺陷。 1.4 本规程在执行之前须通过演示，使AI审查满意。 2. 人

12、员 2.1 从事磁粉检验的NDE人员必须是根据XX宝色钛业XX<<NDE人员培训，考试，资格鉴定和认证实施细那么>>(资料号：QCD-011)进展考试和资格任命的合格人员。 3. 方法综述 3.1 原那么上，磁粉检验方法是指在工件受检区域外表施加铁磁粉，裂纹或其它缺陷会导致正常磁场畸变，使外表上的磁粉形成一定图形，这些图形通常是探测到的缺陷特征。 3.2 磁粉检验法的灵敏度以外表缺陷处为最高，并随离外表深度的增加而迅速降低；因此，本方法仅适用于检验材料或部件的外表或近外表缺陷。 4. 磁化设备校验 4.1 MT设备采用CDX-4型磁轭式探伤仪。 4.2 设备校验4.2.

13、1 校验周期：每一带电流表的磁化设备至少应每年校验一次；设备进展过重要电源修理，周期大修或损坏时，必须得到校验。如果设备已一年或一年以上未使用，那么在第一次使用之前必须校验。4.2.2 磁轭提升力的校验 提升力用标准重块提升法来校验。交流电磁轭提升力至少为10lb(44N)(最大磁轭间距);直流电磁轭提升力至少为40lb(177N)( 最大磁轭间距)。 5. 检验介质* Co.,Ltd.焊缝检验规程3Rev.:0Page:4of 7Title: PROCEDURE FOR MAGNETIC PARTICLE EXAMINATIONferromagnetic particles which ha

14、ve high permeability and low retentivity. The size and shape of the magnetic particles shall be suitable for forming magnetic particle indications. 5.2 The black magnetic particles HK-1-400or 350, made by yixin Citong Co Ltd., shall be used. 5.3 The fluid medium for the magnetic suspension fluid sha

15、ll be transformer oil, smelless kerosene or water. The temperature of the wet particle suspension and the surface of the part shall not exceed 1350F(570C). 5.4 Concentration of wet magnetic particle suspensions5.4.1 The initial bath concentration of suspended magnetic particles should be as specifie

16、d of as remended by the manufacturer and should be checked by settling volume measurements and maintained at the specified concentration on a daily basis. If the concentration is not maintained properly, test results can vary greatly.5.4.2 The bath concentration shall be maintained within 1.2 to 2.4

17、 ml per 100ml of vehicle for nonfluorescent particles unless otherwise specified by the particle manufacturer.5.4.3Bath concentration is normally determined by measuring its setting volume through the use of an ASTM Pear-shaped centrifuge tube with a 1.5-ml stem(0.1-ml divisions )for nonfluorescent

18、suspensions. Before sampling, run the suspension through the recirculating system for at least 30-min to assure thorough mixing of all particles which could have settled on the sump screen and along the sides or bottom of the tank. Take a 100-mL portion of the suspension from the hose or nozzle and

19、allow it to settle for approximately 30 min. The volume settling out at the bottom of the tube is indicative of the particle concentration in the bath. If the bath concentration is low in particle content, add a sufficient amount of particle materials to obtain the desired concentration. If the susp

20、ension is high in particle content, add sufficient vehicle to obtain the desired concentration.5.4.4 If the settled particles appear to be loose agglomerates rather than a solid layer, take a second sample. If still agglomerated, the particles may have bee magnetized, replace the suspension. 6. Magn

21、etization Procedure 6.1 Yoke Technique 6.1.1 The direct, alternating current electromagnetic yokes or permanent magnet yokes shall be used for localized magnetization to form a longitudinal magnetic field.6.1.2 The alternating current electromagnetic yoke shall have a lifting power of at least 10 lb

22、. (4.5kg) at maximum pole spacing. The direct current electromagnetic yoke shall have a lifting power of at least 40 lb. (18.1kg) at the maximum pole spacing.6.1.3 The field strength of yokes can be empirically determined 5.1 检验介质是具有高导磁率和低顽磁性的细铁磁粉，其尺寸和形状必须易于形成磁粉显示。 5.2 应使用宜兴磁通探伤材料公司生产的黑磁粉HK-1-400或35

23、0。 5.3 磁悬液的液体介质必须是变压器油、无味煤油或水。磁悬液的温度和工件外表温度均不得超过1350F(570C)。 5.4 湿磁粉悬浮液的浓度5.4.1 磁悬液浓度应按制造厂推荐，用沉淀量值验证，务使日常浓度一定。浓度不当，会大大影响探伤结果。5.4.2 除制造厂另有规定外，非荧光磁粉悬浮液浓度应为每100ml 1.2-2.4ml的水平。5.4.3 槽中磁悬液浓度通常是用ASTM的梨形离心管测定其沉淀值来确定的，对非荧光磁粉悬液为1.5ml 芯柱(0.1ml刻度)的沉淀柱；在取样以前，将悬浮液在再循环系统中至少流动30分钟，以保证所有磁粉的完全混合，否那么磁粉可能在油盘滤网和沿槽的壁或底

24、沉淀下来，从软管或管嘴取100ml悬浮液并使它沉淀大约30分钟，大管底沉淀的体积 是槽液磁粉浓度指示值；假设磁悬液中磁粉浓度大低，加足够量的磁粉以获得所需浓度；假设磁悬液中磁粉浓度大高，那么加足够的液体介质以获得所需浓度。5.4.4 假设沉淀磁粉表现为松散的团块，而不是严密的敷层，那么应作第二次取样试验，如果还是团块，说明磁粉可能已被磁化，这时需更换悬浮液。 6. 磁化过程 6.1 磁轭法6.1.1 可采用直流的、交流的电磁轭或永久磁轭、来磁化一个局部区域、形成一个纵向磁场。6.1.2 交流电磁轭的提升力应至少在两极间距离最大时为10磅(4.5公斤)。6.1.3 经历磁轭式磁场强度可测量它*

25、Co.,Ltd.焊缝检验规程3Rev.:0Page:5of 7Title: PROCEDURE FOR MAGNETIC PARTICLE EXAMINATIONby measuring its lifting power.6.1.4 Direction of magnetization: At least two separate examinations shall be carried out on each area. The second examination shall be with the lines of magnetic flux approximately perpen

26、dicular to those used for the first examination in that area.6.1.5 The area to be examined shall be restricted to the area which is equal to 1/4 maximum pole spacing on both sides of the line through two poles. The pole spacing shall at least have 1in. (25mm)overlap each time. 7. Magnetic Field Stre

27、ngth 7.1 The special carbon steel / copper plate type field indicator is used to verify that an adequate field strength and direction for the surface of part is obtained. If the clear magnetic particle pattern is shown on the copper plate side of the field indicator, it indicates that adequate field

28、 strength is obtained. 8. Examination Requirements 8.1 Surface Preparation8.1.1 Satisfactory results are usually obtained in the as-welded, as-rolled, as-cast, or as-forged conditions. However, surface preparation by grinding or machining may be necessary where surface irregularities could mask indi

29、cations due to discontinuities.8.1.2 Prior to magnetic particle examination, the surface to be examined and all adjacent areas within at least 1in.(25mm) shall be dry and free of all dirt, grease, lint, scale, welding flux and spatter, oil, or other extraneous matter that could interfere with the ex

30、amination.8.1.3 Cleaning may be acplished using detergents, organic solvents, descaling solution, paint removers, vapor degreasing, sand or grit blasting, or ultrasonic cleaning methods.8.1.4 If coatings are left on the part in the area being examined, it must be demonstrated that indications can be

31、 detected through the existing maximum coating thickness applied. When AC yoke technique is used, the demonstration must be in accordance with Mandatory Appendixof Article 7 of ASME Code Section. 8.2 Unless specified on the drawings or other technical documentation, the magnetic particle examination

32、 shall be carried out on the parts with finished surface condition, or finished-machined condition and final heat treatment condition. 8.3 The small opening, slots or holes in the parts can be blocked to prevent the magnetic particle from getting into. 8.4 Examination shall be conducted with suffici

33、ent overlap 的提升力来确定。6.1.4根据经历磁轭式磁场强度可测量它的提升力来确定。6.1.4 磁化方向 每一区域应至少进展两次分别检验。在第二次检验中，磁通线的方向应大致与第一次检验区域所采用的方向相垂直。6.1.5受检区域应限制在两磁极连线的双侧，相当于1/4最大磁极间距的X围内，磁极间距每次至少有1英寸25毫米的搭接。 7.磁场强度 7.1使用专用的碳钢/铜板磁场指示器来校验零件外表的磁场强度和方向是否满足要求。如果铜板边有清晰的磁粉线条，那么说明磁场强度是足够的。 8检验要求 8.1外表制备8.1.1经焊接、轧制、铸造、锻造等加工的零件，一般会取得满意的效果。然而，外表不平

34、不均匀会掩饰缺陷的显示，那么这些地方要通过打磨或机加工进展外表制备。8.1.2在磁粉检验之前，被检验的外表及其附近至少1英寸25mm的区域内应实枯燥的，并且没有任何污垢、纤维屑、锈皮、焊剂和焊接飞溅、油污或其他能阻碍检验的外来物。8.1.3可使用去污剂、有机溶剂、除绣剂、除绣液、去漆剂、蒸气除油、喷沙或超声波清洗等方法到达清洁的目的。8.1.4如果在被检验部件外表存在漆层等覆盖物，必须进展演示实验，使缺陷能透过覆盖层最厚处显示出来。使用磁轭法时，应按ASME法规第卷第7章强制性附录之要求，验证涂层厚度的影响。 8.2 除非图纸或其他技术文件中另有规定，任何零件均应在完工的外表状态，或最终机加工

35、状态，或最终热处理状态下进展磁粉探伤。 8.3 零件上的小开口、槽或孔，应在检验前堵塞好以防磁粉进入。 8.4 检验时应有足够的重叠(至少10%)，保证受检零件在规定的灵敏度下能得到100%的履盖。* Co.,Ltd.焊缝检验规程3Rev.:0Page:6of 7Title: PROCEDURE FOR MAGNETIC PARTICLE EXAMINATION(at least 10%) to assure 100% coverage at the established sensitivity. 8.5 The repaired area shall be reexamined accor

36、ding to the original examination procedure.8.6 The intensity of the visual light at the surface of the part /work piece undergoing examination shall be a minimum of 50fc (500lx). 9. Evaluation of indications and acceptance standards 9.1 Evaluation of indications Indications will be revealed by reten

37、tion of magnetic particles. All such indications are not necessarily imperfections, however, since excessive surface roughness, magnetic permeability variations (such as at the edge of heat affected zones), etc., may produce similar indications . An indication is the evidence of a mechanical imperfe

38、ction. Only indications which have any dimension greater than 1/16in. (1.6mm) shall be considered relevant. a. A linear indication is one having a length greater than three times the width. b. A rounded indication is one of circular or elliptical shape with a lenth equal to or less than three times

39、the width. c. Any questionable or doubtful indications shall be reexamined to determine whether or not they are relevant. d. Broad areas of particle accumulation which might mask indications from discontinuities are prohibited, and such areas shall be cleaned and reexamined. 9.2 Acceptance standards

40、 (per Appendix 6 of Section Div.1) These acceptance standards shall apply unless other more restrictive standards are specified for specific materials or applications. All surfaces to be examined shall be free of : a. relevant linear indications; b. relevant rounded indications greater than 3/16in.

41、(4.8mm); c. four or more relevant rounded indications in a line separated by 1/16in.(1.6mm)or less, edge to edge; d. an indication of an imperfection may be larger than the imperfection that causes it; however, the size of the indication is the basis for acceptance evaluation. 10. Demagnetization When residual magnetism in the part could interfere with subsequent processing or usage