焊接杂记 - 图文

NDE Level Ⅲ: AI: NJBST Co.,Ltd. QCD-014 Rev.:0 Page:3 of 8 Title: 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 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 procedure 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 NJBST Co.,Ltd.’s “Written Practice for NDE Personnel Training, Examination, Qualification & Certification”(No.:QCD-011). 3. Description of Method 3.1 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 distortions 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 surface. Therefore, this method 1. 概述 1.1 本规程适用 于ASME规范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表面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表面开口缺陷。 1.4 本规程在执行之前须通过演示，使AI审查满意。 2. 人员 2.1 从事磁粉检验的NDE人员必须是根据南京宝色钛业有限公司<>(资料号：QCD-011)进行考试和资格任命的合格人员。 3. 方法综述 3.1 原则上，磁粉检验方法是指在工件受检区域表面施加铁磁粉，裂纹或其它缺陷会导致正常磁场畸变，使表面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表面缺陷处为最高，并随离表面深度的增加而迅速降低；因此，本方法仅适用于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 Equipment 4.2.1 Frequency of calibration: 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 Calibration 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 have 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 NJBST Co.,Ltd. QCD-014 Rev.:0 ferromagnetic particles which have 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 shall 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 suspensions 5.4.1 The initial bath concentration of suspended magnetic particles should be as specified of as recommended 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 ml per 100ml of vehicle for nonfluorescent particles unless otherwise specified by the particle manufacturer. 5.4.3 Bath 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 检验材料或部件的表面或近表面缺陷。 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 4.2.1 校验周期：每一带电流表的磁化设备至少应每年校验一次；设备进行过重要电源修理，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，则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 Page:4 of 8 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350。 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表面温度均不得超过1350F (570C) 。 Title: PROCEDURE FOR MAGNETIC PARTICLE EXAMINATION 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