Aws Module 10.ppt

MODULE 10 – VISUAL INSPECTION AND OTHER NDE METHODS & SYMBOLS

WELDING INSPECTION TECHNOLOGY

BEFORE, DURING AND AFTER WELDING INSPECTION  BEFORE WELDING  REVIEW APPLICABLE DOCUMENTATION 

CHECK WELDING PROCEDURE



CHECK INDIVIDUAL WELDER QUALIFICATION



ESTABLISH HOLD POINTS



DEVELOP INSPECTION PLAN



DEVELOP PLAN FOR RECORDING INSPECTION RESULTS AND MAINTAINING THOSE RECORDS



DEVELOP SYSTEM FOR IDENTIFICATION OF REJECTS

 BEFORE WELDING  CHECK CONDITION

OF WELDING EQUIPMENT



CHECK QUALITY AND CONDITION OF BASE AND FILLERMATERIALS TO TO BE USED



CHECK WELD PREPARATIONS



CHECK JOINT FIT-UP



CHECK ADEQUACY OF ALIGNMENT DEVICES



CHECK WELD JOINT CLEANLINESS



CHECK PREHEAT, WHEN REQUIRED

 DURING WELDING  CHECK WELDING VARIABLES FOR COMPLIANCE WITH WELDING PROCEDURE



CHECK QUALITY OF INDIVIDUAL WELD PASSES



CHECK INTERPASS CLEANING



CHECK INTERPASS TEMPERATURE



CHECK PLACEMENT AND SEQUENCING OF INDIVIDUAL WELD PASSES



CHECK BACKGOUGED SURFACES



MONITOR IN-PROCESS NDT, IF REQUIRED

 AFTER WELDING  CHECK FINISHED WELD APPEARANCE 

CHECK WELD SIZE



CHECK WELD LENGTH



CHECK DIMENSIONAL ACCURACY OF WELDMENT



MONITOR ADDITIONAL NDT, IF REQUIRED



MONITOR POST WELD HEAT TREATMENT



PREPARE INSPECTION REPORTS

NONDESTRUCTIVE TESTING (NDT)  TESTS DEVELOPED TO PROVIDE AN INDICATION OF THE ACCEPTABILITY OF THE TEST OBJECT WITHOUT RENDERING IT UNUSABLE FOR  SERVICE. NDT METHODS

 PENETRANT

TEST (PT)



MAGNETIC PARTICLE TEST (MT)



RADIOGRAPHIC TEST (RT)



ULTRASONIC TEST (UT)



EDDY CURRENT TEST (ET)

 PENETRANT TEST

- PENETRANT TESTING REVEALS SURFACE DISCONTINUITIES BY THE BLEEDOUT OF A

PENETRATING MEDIUM AGAINST A CONTRASTING COLORED  TWO PENETRANT INDICATIONS BACKGROUND.  VISIBLE



FLUORESCENT

 METHOD OF EXCESS PENTRANT REMOVAL  WATER WASHABLE – CONTAIN AN EMULSIFIER WHICH ALLOWS THE OILY PENETRANT TO BE RINSED OFF FROM THE SURFACE W/ A LOW PRESSURE WATER WASH.

 METHOD OF EXCESS PENTRANT REMOVAL  SOLVENT REMOVABLE – REQUIRE SOLVENT TO REMOVE THE SURFACE PENETRANT FROM THE TEST OBJECT.



POST-EMULSIFIABLE – ARE REMOVED BY ADDING AN EMULSIFIER AFTER THE DWELL TIME.

 SIX DIFFERENT TYPES OF PENETRANTSOF EMULSIFIER - APPLICATION PERMITS THE  VISIBLE/WATER WASHABLE PENETRANT TO BE REMOVED BY WATER.  VISIBLE/SOLVENT REMOVABLE



VISIBLE/POST-EMULSIFIABLE

 SIX DIFFERENT TYPES OF PENETRANTS (CONTINUED)  FLUORESCENT/WATER WASHABLE



FLUORESCENT/SOLVENT REMOVABLE



FLUORESCENT/POST-EMULSIFIABLE

 THE PENETRANT IS ALLOWED TO REMAIN ON THE TEST SURFACE FOR A PERIOD OF 5 AND 30 MINUTES, WHICH IS CALLED  ADVANTAGES “DWELL TIME”.

 THE USE OF PENTRANT IS NOT LIMITED TO METALLIC MATERIALS



WELL SUITED FOR EVALUATING WELD OR BRAZED JOINTS BETWEEN DISSIMILAR METALS



PROCESS IS QUITE PORTABLE

 DISADVANTAGES  IT WILL NOT DETECT SUBSURFACE DISCONTINUITIES 

RELATIVELY TIME-CONSUMING TEST WHEN COMPARED TO MPT



CLEANING REQUIRED FOR CERTAIN APPLICATION



THE PRESENCE OF SURFACE NONRELEVANT INDICATIONS MAY MAKE INTERPRETATION DIFFICULT.

 MAGNETIC PARTICLE TEST (MPT)

- USED PRIMARILY TO

DISCOVER DISCONTINUITIES IN FERROMAGNETIC PERMANENT MAGNET YOKE

MATERIALS.

LINES OF FORCE

N S DISCONTINUITY



TWO METHODS OF MPT

 DRY METHOD – CALLED THE DRY MAGNETIC PARTICLE METHOD



WET METHOD – ALSO CALLED THE OIL OR WATER SUSPENSION PARTICLE METHOD - HAS HIGHER SENSITIVITY

 ADVANTAGES  APPLICATION OF MAGNETIC PARTICLE INSPECTION INCLUDE THE EVALUATION OF MATERIALS WHICH ARE CONSIDERED TO BE MAGNETIC AT THE TEST TEMPERATURE.



EQUIPMENT IS PORTABLE



RAPID TESTING SPEED AND LOW COST



VERY GOOD FOR SURFACE DISCONTINUITY DETECTION



TEST CAN BE DONE THROUGH THIN PAINT COATINGS

 DISADVANTAGES  CAN ONLY BE USED ON MATERIALS THAT CAN BE MAGNETIZED



MOST PARTS REQUIRE DEMAGNETIZATION AFTER TESTING AND THAT VERY THICK COATINGS MAY MASK DETRIMENTAL INDICATIONS



ROUGH SURFACES SUCH AS THOSE SEEN ON WELDS OR CASTINGS CAN MAKE EVALUATION MORE DIFFICULT

 RADIOGRAPHIC TESTING (RT) – THIS METHOD IS BASED ON THE PRINCIPLE OF PREFERENTIAL RADIATION ABSORPTION.

SOURCE

TRANSMISSION, OR

X-RAYS

STEEL STEP WEDGE FILM

DARKEST LIGHTEST EFFECT OF PART THICKNESS ON RADIATION TRANSMISSION (ABSORPTION)

EFFECT OF MATERIAL DENSITY ON RADIATION TRANSMISSION (ABSORPTION) SOURCE X-RAYS Pb

Cu

Fe

Al FILM

LIGHTEST

DARKEST

SOURCE

X-RAYS

FILM

ORIENTATION OF RADIATION SOURCE, TEST PLATE AND RADIOGRAPHIC FILM

 ADVANTAGES  IT CAN DETECT SUBSURFACE DISCONTINUITIES IN ALL COMMON ENGINEERING MATERIALS



THE DEVELOPED FILM SERVES AS AN EXCELLENT PERMANENT RECORD OF THE TEST IF THE FILM IS STRORED AWAY FROM  PROPERLY DISADVANTAGES EXCESSIVE HEAT AND LIGHT  HAZARDOUS TO HUMANS BECAUSE OF THE EXCESSIVE RADIATION EXPOSURE



VERY EXPENSIVE EQUIPMENT



OPERATORS AND INTERPRETERS REQUIRE LENGTHY TRAINING PERIODS

 ULTRASONIC TEST (UT) – IS AN INSPECTION METHOD WHICH USES HIGH FREQUENCY SOUND WAVES, TO MEASURE PROPERTIES IN

GEOMETRIC AND PHYSICAL - UT USES ELECTRICAL ENERGY IN THE FORM OF MATERIALS. AN APPLIED VOLTAGE, AND THIS VOLTAGE IS CONVERTED BY A TRANSDUCER TO MECHANICAL ENERGY IN THE FORM OF SOUND WAVES. - THE TRANSDUCER ACCOMPLISHES THIS ENERGY CONVERSION DUE TO A PHENOMENON REFERRED TO AS “PIEZOELECTRIC” EFFECT.

 TWO TYPES OF TRANSDUCERS  LONGITUDINAL OR STRAIGHT BEAM – USE TO DETERMINE MATERIAL THICKNESSES OR THE DEPTH OF A DISCONTINUITY BELOW THE MATERIAL THICKNESS.



SHEAR WAVES OR ANGLE BEAM – ARE USED EXTENSIVELY FOR WELD EVALUATION BEACAUSE THEY SEND THE SOUND INTO THE PART AT AN ANGLE.

 TWO GENERAL TYPES OF UT  CONTACT TESTING – THE TRANSDUCER IS ACTUALLY PLACED AGAINST THE SURFACE OF THE PART

 IMMERSION – THE PART TO BE EVALUATED IS PLACED UNDERWATER AND THE SOUND IS TRANSMITTED FROM THE TRANSDUCER AND INTO THE PART THROUGH THE WATER.

 ADVANTAGES  CONSIDERED TO BE A VOLUMETRIC TEST 

IT IS CAPABLE OF DETERMINING NOT ONLY THE LENGTH AND AND LATERAL LOCATION OF A DISCONTINUITY, BUT IT WILL ALSO PROVIDE THE OPERATOR WITH A DETERMINATION OF A DEPTH OF THAT FLAW BENEATH THE SURFACE.



IT WILL BEST DETECT THOSE MORE CRITICAL PLANAR

DISCONTINUITIES SUCH AS CRACKING AND INCOMPLETE FUSION.



HAS DEEP PENETRATION ABILITY UP TO 200 in. IN STEEL AND CAN BE VERY ACCURATE

 DISADVANTAGES  IT REQUIRES A HIGHLY SKILLED AND EXPERIENCED OPERATOR BECAUSE INTERPRETATION CAN BE DIFFICULT.



THE TEST OBJECT MUST BE FAIRLY SMOOTH, AND COUPLANT IS REQUIRED FOR CONTACT TESTING.



REFERENCED STANDARDS ARE REQUIRED, AND THIS TEST METHOD FOR WELD INSPECTION IS GENERALLY LIMITED TO GROOVE WELDS THAT ARE THICKER THAN ¼ in.

 EDDY CURRENT TEST (ET) – WHEN A COIL CARRYING AC IS BROUGHT NEAR A METAL SPECIMEN, EDDY CURRENT ARE INDUCED IN THE METAL BY ELECTRO ADVANTAGES

MAGNETIC INDUCTION.  CAN BE USED TO MEASURE THE THICKNESS OF THIN SECTIONS, ELECTRICAL CONDUCTIVITY, MAGNETIC PERMEABILITY, HARDNESS, AND THE HEAT TREATMENT CONDITION OF TEST OBJECT.



THIS METHOD CAN ALSO BE USED TO SORT DISSIMILAR METALS AND TO MEASURE THE THICKNESS OF

 ADVANTAGES  IT CAN BE READILY AUTOMATED 

THE PROBE NEED NOT TOUCH THE TEST OBJECT, NO COUPLANT IS REQUIRED, AND THE METHOD IS EXPEDIENT, ALL OF WHICH MAKES “ASSEMBLY LINE” INSPECTION RELATIVELY EASY.



CAN BE USED FOR THE INSPECTION OF ANY ELECTRICALLY CONDUCTIVE MATERIAL, WHETHER MAGNETIC OR NONMAGNETIC.