8BEND TESTING Shows Physical condition of the weld Determine welds efficiencyTensile strengthDuctilityFusion and penetration
9BEND TEST Bend through 180O the specimen should be a minimum of 30mm wideThe fulcrums diameter is 3x thickness of the plateThe bottom rollers have a distance of the diameter of the former times the thickness of the plateUpper and lower surfaces ground or filed flat and edges rounded off.the tests should be one against the root -another against the face ,and in some cases a side bend.
13IMPACTCHARPY AND IZODGives the toughness and shock loading of the material and weld at varying temperatures with a notch such as under cutThe measurement is the energy required to to break a specimen with a given notch2mm depth at a 45obevel or a “U” notch.
23FATIGUE the testing of Material that is subject to fluctuating loads HAIGH Electro magnetic tester.W’O’HLER Uses rotating chuck with weight
24CRACKING REEVES Test study the hardening and cracking of welds. The compatibility of electrodes for the metal being joined.
25CRACKING Three Sides Are Welded With Known Compatible Electrodes. The front edge is welded with the test electrode.if incompatible it will crack.
26MICROSCOPICUsed to determine the actual structure of the weld and parent metalUp to 50,000 times magnification with an electron beam microscopePolishing must be of a very high standard
27MACROSCOPIC Examined using a magnifying glass . magnification from 2 to 20 time.it will show up slag entrapment or cracks .polishing not as high as micro.
28ETCHING REAGENTSThese are acids used to show up different structures in metalsFor steels the most common is “1-2 % nitric acid in distilled water or alcohol.Aluminum uses a solution of 10-20%caustic soda in water
32VISUAL While welding After welding The rate the electrode melts The way the weld metal flowsSound of the arcThe light given ofAfter weldingUnder cutLack of root fusionAny pin holes from gas or slagAmount of spatterDimensions of weld
33DYE PENETRANTS These are an aid to visual inspection Will only find surface defectsUse correct type
37MAGNETIC PARTICLE Mainly for surface defects Some sub surface defects can be foundOnly ferrous metal
38ACOUSTICS Striking with a rounded object Ringing tone if no defect Tone changes when object is cracked
39APPLICATION OF A LOAD Used to test pressure vessels Pipe lines The item for testing is filled with water or oil it is then pressurised using a pumpA safety valve is set 1.5 to 2 times below the working pressure.