NDT Examination procedure.doc

Jiangsu Changbo Shipyard Co.,LTDTechnics:NDT EXAMINATION PROCEDURETotal pagesNumber1pageTechnics No: Edit：0Product No:Date:Edit excerptaEditDateChapterPage NoEdit excerptaCompilationAuditingSurveyor ApproveSignatureDate Jiangsu Changbo Shipyard Co.,LTDTechnics:NDT EXAMINATION PROCEDURETotal pagesNumber pageTechnics No: Edit：0Date:RADIOGRAPHIC EXAMINATION PROCEDURE1 .PurposeThis procedure is due to effective control of the Radiographic examminationReference Standard : CB/T3558-94 CB/T3177-942 . Application scopeThis procedure is applied to the radiographic examination of weld seams .contains preparetion and through the whole examination 3 Choose premise Testing a given work should be in accordance with relevant standards select the appropriate testing conditions . CB/T3558-94 should be the basis for the selection , Welding seam transillumination according to the film image quality from low to high hierarchized ordinary grade and premium grade .Ship welding seam should meet the ordinary grade.Different film image quality grade have different specification for densitometer, sensitivity ,definition . To meet the standard of the film image quality , shuold prepare from the equipment , method,condition at first .4 Determination of camera specificationsDuring the camera , except the reasonable choice for radiographic method , should choose the better specification to make the small defect cane be shown on the film, in order to achieve the high sensitivity . Some choices of the specifications:1) Ray source option , Should choose a small size-ray source2) Transillumination distance option , Select focus mostly between 600mm to 700mm3) Film and intensifying screen option, When cameraing ,usually use a thickness of 0.01-0.03 mm foil intensifying screen and non- intensifying film together射线探伤操作工艺规程1 目的该项操作规程，对船舶产品的射线探伤实施有效控制。引用标准：CB/T3558-94CB/T3177-942适用范围 本规程适用于对船舶焊缝进行无损检测射线探伤前应做的准备工作和射线探伤中全过程的管理。3选择的前提 对给定工件进行射线探伤时，应根据有关规程和标准要求选择适当的探伤条件。应以船标CB/T3558-94为选择条件的依据，焊缝透照按底片影像质量由低而高的要求分普通级、特级二种检验等级。船舶焊缝的射线探伤，至少应满足普通级的要求。 不同的象质等级对底片的黑度、灵敏度与不清晰度有不同的规定。要满足规定等级的象质要求，从探伤器材、方法、条件及程度等各个方面都要预先进行全面地部署。4照相规范的确定在照相过程中，除了合理地选择透照方法外，还必须选择好透照规范，使小缺陷能够在底片上明显地辨别出来，从而达到高灵敏度。有关规范的选择： 1)射线源的选择，应选择小尺寸的射线源； 2)透照距离的选择。在透照中，焦距选择大多在600700mm间； 3)胶片与增感屏的选择。通常照相时将厚度为0.010.13mm的铅箔增感屏与非增感形胶片一起使用。Jiangsu Changbo Shipyard Co.,LTDTechnics:NDT EXAMINATION PROCEDURETotal pagesNumber pageTechnics No: Edit：0Date:5 Geometric parameters optionGeometric parameters is an important factors affecting sensitivity of radiation, therefore must be comprehensive considered and rational choice1) Focus or side of the ray source : Focus on the size has an impact on the defect in the-ray film with the display contrast and clarity 2) Focus on size and geometric layout can cause blurred images, and zoom3) Focus on size and ray film contrast-4) X-ray intensity distribution5) Transillumination distance option L1- On the Uy value and the K value of the effective length should be comprehensive considered6 Choice of exposure conditions and correctTo meet Ray Radiographic conditions and have a good film quality, usually choose proper black level, and the sensitivity of exposure conditions. Several mainly factors :1) Exposure Factor2) The choice of exposure conditions,3) The correction of exposure conditions4) Film to reach the specified range of Blackness7 Transmittance logIn order to assess the sensitivity of the film. Need to use this instrument, it is used to check the transillumination techniques and film processing quality. Chinese CB/T3558-94 Ships Welds Radiography technology and quality grading require use different thickness metal wire arranged equidistant linear as the image quality log,With the film must be shown the minimum wire diameter and relative index to indicate the sensitivity5几何参数的选择几何参数是影响射线照相灵敏度的重要因素，因此必须综合考虑与合理选择。 1)焦点或射线源尺寸：焦点大小对缺陷影响在射线底片上的显示对比度和清晰度都有很大影响； 2)焦点尺寸和几何布置会引起的影像模糊及放大； 3)焦点尺寸与射线底片对比度； 4)照射场内的X射线强度分布； 5)透照距离L1的选择对Uy值和满足K值的有效长度要综合考虑。6曝光条件的选择及修正为得到满足射线透照应该具备的条件与象质良好的底片，通常要选择能够得到适当黑度和灵敏度的曝光条件进行透照。主要有以下几个因素： 1)曝光因子； 2)曝光条件的选择； 3)曝光条件的修正； 4)底片黑度达到确定的范围。7透度计 为了评定底片的灵敏度，需要采用透度计，透度计是用来检查透照技术和胶片处理质量的。我国CB/T3558-94船舶钢焊缝射线照相工艺和质量分级标准规定使用粗细不同的几根金属丝等距离排列做成的线型象质计，用底片上必须显示的最小钢丝直径与相应的象质指数来表示照相的灵敏度。Jiangsu Changbo Shipyard Co.,LTDTechnics:NDT EXAMINATION PROCEDURETotal pagesNumber pageTechnics No: Edit：0Date:8 Weld Radiographic Methodgeometrical parameters must be determined in the transillumination method : Focal length F (include the L1 distance from the ray source to the workpiece surface and L2 distance from the workpiece surface to the film ) the length of transillumination L3 , surround weld 100% , Minimum exposure times N , the factors that need to be considered : Geometric non- Definition Uy , Thickness ratio K , Transverse crack angle Q ，Longitudinal crack angle Q Effective assessment length LEFF and the length of the adjacent two lap under 100% transillumination L，Geometrical parameters and related factors in different ways have different technical requirements9 DEVELOPER's configurationConfiguration methods and procedures must be suitable for the developing of show images . When configured its better to use distilled water or boiled warm water and related drugs 10 Fixer deploymentAcidic Fixer contains mutual decomposition element , To rely on other drugs in order to co-exist , Therefore, the preparation of pharmaceutical procedures, temperature and mixing should pay particular attention11Washing and drying1) Fixed film, it should be washed in the flow of clean water 20 to 30 minutes , The objective is to rinse the surface and inner layer of film adsorption impurities and silver compounds2) Drying can use a simple drying rack , height wall to dry naturally or dry in a clean ventilation room 12 Safety and protectionIn order to protect the health and safety of residents and staff , according to restrictions imposed by the International Radiation Commission , State promulgated The basic standards of radiation protectionGB4792 -84 ,radiation workers , during the whole life Whole body irradiation inside and outside the cumulative amount of not more than 250 rem , the worker can refuse to check when the site situation is not ready Radiation dose control methods1) time : Control of radiation exposure time on the human body, Radiation field to allow the maximum dose of 2.5 micro-rem2) ditance : control the diatance from the ray-source to the huamn body8焊缝透照方法 在透照方法中必须确定的几何参数是：焦距F（包括射源至工件表面的距离L1和工件表面至胶片的距离L2）、一次透照长度L3、环焊缝100%、透照时的最少曝光次数N；同时需要考虑的因素是：几何不清晰度Uy、透照厚度比K、横裂检出角、纵裂检出角、有效评定长度Leff以及100%透照时相邻两片的搭接长度L、几何参数和相关因素在不同的透照方法中均有不同的技术要求。9显影液的配制方法 为了使显影过程能正常进行，显影液的配制方法与程序必须合适。配制显影液时最好用蒸馏水或煮沸过的温水和有关的药品组成。10定影液的调配 酸性定影液中含有互相分解的成分，要靠其它药品的作用才能共存，所以对药品的配制程序、温度和搅拌都要特别注意。11水洗和干燥1）胶片经定影后，应在流动的清水中冲洗2030分钟。冲洗的目的是将胶片表面和内层吸附的硫代硫酸钠杂质及银的洛合物清除掉。2）干燥可采用简易的晾片架，放在墙壁高处进行自然干燥或在清洁通风的空间晾干。12安全保护 为了保障我国从事放射工作人员和广大居民的的健康和安全，根据国际放射防护委员会所规定的限值，国家制定颁布了我国现行防护标准放射卫生防护基本标准，在GB4792-84中规定职业放射工作人员，其全身内外照射的终身累积剂量当量不得超过250雷姆，并且现场条件不具备时探伤人员有权拒绝探伤。Jiangsu Changbo Shipyard Co.,LTDTechnics:NDT EXAMINATION PROCEDURETotal pagesNumber pageTechnics No: Edit：0Date:3) Shield : Ray's intervals in the human body and a layer of absorbing material The activity must be based on sources, uses and nature of the work At the same time must also consider the costs and sources of materialStatement : this procedure was drafted by the QC dapartment , responsible for interpretation of the contents辐射剂量的控制方法：1)时间：要控制射线对人体的曝光时间，照射场中所容许的最大剂量率是2.5毫雷姆/时（25微希沃特/时）；2)距离：要控制射线源到人体间的距离；3)屏蔽层：在人体和射线源之间隔一层吸收物质。必须根据辐射源的活度、用途和工作性质来具体选择。同时还必须考虑成本和材料来源。说明：本射线探伤操作规程由质量管理科起草，并负责对其内容进行解释。Jiangsu Changbo Shipyard Co.,LTDTechnics:NDT EXAMINATION PROCEDURETotal pagesNumber pageTechnics No: Edit：0Date:Darkroom operation procedure1 Purpose Darkroom processing is an important process to ensure the quality of the film, it should be a person assigned to conduct . The operational procedures, for the non-destructive testing-ray film darkroom to provide for the safe operation and ensure the passing rate of the film .2 Application scopeDarkroom processing includes cuting, bagging, developing, fixing, water washing and drying the film so on . 3 Darkroom safety operation3.1 Cuting and bagging , storage for the film 3.1.1 Film totally seprated from the light , sthand in a cool ,dry condition and less than 1m to the heater3.1.2 Film box should be opend in a darkroom , wrapping paper cushion to turn back for preventing exposure3.1.3 Remove the film with backing paper every per-use , Single cut according to specifications, The excess backing paper put into the film box to save, to prevent scratches.3.1.4 Installed film to avoid emulsion or intensifying screen with the Backing Paper, or other coarse material friction, To prevent electrostatic sensitive ; Film can only be taken sides or corners to avoid leaving fingerprints ; film can bot be bended and folded to avoid folded light-sensitive trace3.1.5 operator touch with the film , wash hand fist.3.1.6 the darkroom safe lights should be placed 0.5m away from the film , test before the first time use to prevent the light-sensitive.3.1.7 When the film quality of doubt, should be used before exposure DEVELOPER, fixer analysis, stop with a serious problem暗室操作规程1目的 暗室处理是保证底片质量的重要工序，应指定专人进行。该项操作规程，对无损检测的射线底片暗室安全操作做出规定，以确保底片合格率。2适用范围 暗室处理包括切片、装袋、显影、定影、水冲洗和底片烘干等。本程序适用于射线底片暗室安全操作。3暗室安全操作规程3.1胶片的切装与保管3.1.1胶片应与光线完全隔离，距暖气不少于1m的阴凉干燥处立放。3.1.2胶片盒应在暗室开封，外包装纸余量要折回盖严，以防露光。3.1.3按每次用量带衬纸取出胶片，单张按规格切，多余片衬纸放回胶片盒内保存，以防划伤。3.1.4装胶片要避免乳剂与衬纸或增感屏或其它粗物磨擦，以防静电感光；拿胶片只能触及边或角，以防留下指印；胶片不得折叠和弯曲，以防折迹感光。3.1.5操作人员接触胶片时，应将手洗净，胶片处理前不得粘上显、定影液。3.1.6暗室安全灯应在距胶片0.5m以外安放，第一次使用时须测试，以防胶片感光。3.1.7当对胶片质量有怀疑时，应在曝光前用显、定液影分析，问题严重时应停用。Jiangsu Changbo Shipyard Co.,LTDTechnics:NDT EXAMINATION PROCEDURETotal pagesNumber pageTechnics No: Edit：0Date:3.2 Darkroom processing3.2.1 hand wash process 3.2.1.1 DEVELOPER : the temperature is 1821degree , time is 48 minutes , film be moved up and down to ensure the DEVELOPER freshness , folders to have a certain distance to prevent the film sticking3.2.1.2 wash 1015 seconds after the developing , Do not take developing solution into the fixing tank3.2.1.3 Fixing : film be moved up and down during 1 mintue , the fixing time is 2 times than the Permeability , normally is 15 minutes 3.2.1.4 wash : within the runing clean water ( 2 liter/minute) , normally is 1520 minutes . can not be over 30 minutes to prevent the emulsion paste the dirt .3.2.1.5 Dry film : after the washing , Natural dry, should be in clean and dry well-ventilated place : heating dry , natural drying or drying agent to ensure there is no drop of water , tmp less than 50 degree3.3 responsibility : responsible for improper handling of the filmStatement : this procedure was drafted by the QC dapartment , responsible for interpretation of the contents3.2暗室处理3.2.1手工冲洗规程3.2.1.1显影：其温度为1821，显影时间为48分钟，显影之初和显影过程中要使胶片上下移动，以保证显影液新鲜性。显影夹之间要有一定距离，防止胶片相粘。3.2.1.2显影后水冲洗1015秒，切勿将显影液带入定影槽内。3.2.1.3定影：胶片浸入定影液1分钟内上下移动，定影时间为通透时间的两倍，一般为15分钟。3.2.1.4水冲洗：在流动的清水(流速2立升/分)中进行，一般为1520分钟。不得超过30分钟，以防乳剂膜泡涨粘附污物。3.2.1.5底片干燥：在底片清洗后进行。自然干燥时，应在无尘及干燥通风处晾干；需烘干时，应用去水剂或自然干燥至无水滴时进行，烘干温度50。3.3责任：对暗室处理不当造成的底片不合格负责。说明：本暗室操作规程由质量管理科起草，并负责对其内容进行解释。Jiangsu Changbo Shipyard Co.,LTDTechnics:NDT EXAMINATION PROCEDURETotal pagesNumber pageTechnics No: Edit：0Date:Procedure for Magnetic Particle Examination1. PurposeThis purpose is applied to the magnetic particle examination of ship products.2. Application scopeThis procedure is used to detect plate raw material and pipe material, also it can be applied to forgings, castings and weldments.3. Operation regulation3.1 PrecleaningEnsure there is no lipid or other impurity on the surface of raw material and samples, which can affect distribution of magnetic powder; dispersion; characteristic and articulation of powder deposit.3.2 Detection of defectsMagnetic particle examination should confirm all the defects which could cause damage to the structure. Ensure the magnetic line crosses every defect exists in the sample.3.3 Selection of means of detection1).Wet process Put magnetic suspending liquid on the sample by hosepipe apraying or impregnation method, make the surface totally covred, keep the magnetizing current for 1/5 to 1/2 second, then turn off the current, exert the magnetic suspending liquid by hosepipe spraying or impregnation method.2).Dry process Spray magnetic powder on the examined area, remove excessive powder, shake the sample slightly to achieve equal distribution. Be careful not to spray too much powder so that the reflection of defect will not be so clear.3).Defect detection of near surface When detect near surface, we should carry out wet process, for magnetic flux leakage valve caused by non-metallic impurity is minimum. When inspect near surface of large castings or elements, it is better to do dry process.磁粉探伤操作规程1目的 该项操作规程，对船舶产品的磁粉探伤实施有效控制。2适用范围 本规程适用于原材料板材及管材的探伤，并且也适用于加工产品锻件、铸件、焊接件的探伤。3操作规程3.1预清洗 所有材料和试件的表面应无油脂及其他可能影响磁粉正常分布、影响磁粉堆积物的密集度、特性以及清晰度的杂质。3.2缺陷的探伤 磁粉探伤应以确保满意的测出任何方面的有害缺陷为准。使磁力线在切实可行的范围内横穿过可能存在于试件内的任何缺陷。3.3探伤方法的选择 1）湿法 磁悬液应采用软管浇淋或浸渍法施加于试件，使整个被检表面完全被覆盖，磁化电流应保持1/51/2秒，此后切断磁化电流，采用软管浇淋或浸渍法施加磁悬液。 2）干法 磁粉应直接喷或撒在被检区域，并除去过量的磁粉，轻轻地震动试件，使其获得较为均匀的磁粉分布。应注意避免使用过量的磁粉，不然会影响缺陷的有效显示。 3）检测近表面缺陷 检测近表面缺陷时，应采用湿粉连续法，因为非金属夹杂物引起的漏磁通值最小，检测大型铸件或焊接件中近表面缺陷时，可采用干粉连续法。Jiangsu Changbo Shipyard Co.,LTDTechnics:NDT EXAMINATION PROCEDURETotal pagesNumber pageTechnics No: Edit：0Date:4).Circumferential magnetization Central conductor method is applied to the detection of inner surface of cylindrical sample; there is a gap between sample and conductor so that they wont touch each other. When current crossing the sample, pay attention to avoid burning from the interface. Make sure all interfaces have been cleaned. 5).Longitudinal magnetization When using spiral coil to magnetize the sample, the sample should be set on the right position inside spiral coil. Make sure the spiral coil is big enough to amount the sample.3.4 DemagnetizationPut components in DC magnetic field, keep changing current direction and gradually decrease the current to 0. For large component