无损检测磁粉检验工艺规程

无损检测磁粉检验工艺规程内容摘要：

tank. Take a 100mL portion of the suspension from the hose or nozzle and 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 suspension is high in particle content, add sufficient vehicle to obtain the desired concentration. 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 magized, replace the suspension. 6. Magization Procedure Yoke Technique The direct, alternating current electromagic yokes or permanent mag yokes shall be used for localized magization to form a longitudinal magic field. The alternating current electromagic yoke shall have a lifting power of at least 10 lb. () at maximum pole spacing. The direct current electromagic yoke shall have a lifting power of at least 40 lb. () at the maximum pole spacing. The field strength of yokes can be empirically determined 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。 应使用宜兴磁通探伤材料公司生产的黑磁粉 HK1400 或 350。 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)。 湿磁粉悬浮液的浓度 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。 除制造厂另有规定外，非荧光磁粉悬浮液浓度应为每 100ml 的水平。 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 芯柱 ( 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，否则磁粉可能在油盘滤网和沿槽的壁或底沉淀下来，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；假如磁悬液中磁粉浓度大低，加足够量的磁粉以获得所需浓度；假如磁悬液中磁粉浓度大高，则加足够的液体介质以获得所需浓度。 假如沉淀磁粉表现为松散的团块，而不是紧密的敷层，则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 磁轭法 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。 交流电磁轭的提升力应至少在两极间距离最大时为 10 磅 ( 公斤 )。 经验磁轭式磁场强度可测量它 更多免费资料下载请进： 好好学习社区 ****** Co.,Ltd. 焊缝检验规程 3 Rev.:0 Page:5 of 7 Title: PROCEDURE FOR MAGNETIC PARTICLE EXAMINATION by measuring its lifting power. Direction of magization: At least two separate examinations shall be carried out on each area. The second examination shall be with the lines of magic flux approximately perpendicular to those used for the first examination in that area. 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. Magic Field Strength 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 magic particle pattern is shown on the copper plate side of the field indicator, it indicates that adequate field strength is obtained. 8. Examination Requirements Surface Preparation Satisfactory results are usually obtained in the aswelded, asrolled, ascast, o。