Weld quality standard

I. Guarantee project 1. Welding materials shall meet the design requirements and relevant standards, and quality certificates and baking records shall be checked. 2, the welder must pass the examination, check the welder corresponding welding conditions of the certificate and the date of assessment. 3. Grade ⅰ and ⅱ welds shall be inspected by flaw detection, and shall conform to the design requirements and the provisions of the construction and acceptance specifications, and check the weld flaw detection report. 4, weld surface ⅰ, ⅱ grade weld shall not have cracks, welding tumors, burn through, arc pits and other defects. Grade ⅱ welds shall not have surface holes, slag inclusion, arc pits, cracks, arc scratches and other defects, and Grade ⅰ welds shall not have edge biting, incomplete welding and other defects. Ii. Basic items 1. Weld appearance: uniform weld shape, smooth transition between weld pass and weld pass, weld pass and base metal, and clean welding slag and spatter. 2. Surface porosity: grade ⅰ and ⅱ welds are not allowed; The allowable diameter of grade ⅲ weld seam is less than or equal to 0.4t per 50mm length; And 2 pores ≤3mm; Spacing of pores ≤6 times aperture. 3. Edge biting: Grade I welds are not allowed. Grade ii weld: bite depth ≤ 0.05T, and ≤0.5mm, continuous length ≤100mm, and the total bite length on both sides ≤10% of the weld length. Grade ⅲ weld: bite edge depth ≤0 lt, and ≤ LMM. Note: T is the thickness of the thinner plate at the joint. Iii. Protection of finished products 1. After welding, it is not allowed to hit the joint and water the steel just welded. Slow cooling measures should be taken at low temperature. 2, do not arbitrarily arc on the base metal outside the weld. 3, all kinds of components can be welded after the correction, and shall not move the pad iron and fixture at will, in order to prevent the size deviation of components. Concealed part of the weld must be completed concealed acceptance procedures before the next concealed process. 4, low temperature welding is not allowed to immediately remove slag, should be carried out after the weld temperature. Four, should pay attention to the quality problems 1. The size exceeds the allowable deviation: the relative position size of the welding part should be strictly controlled for the insufficient length, width and thickness of the welding seam, the deviation of the center line, and the deviation of bending, and the qualified rear should be welding, and the welding should be carefully operated. 2, weld cracks: in order to prevent cracks, should choose the appropriate welding process parameters and welding procedures, avoid using large current, do not suddenly flameout, weld joints should be 10 ~ 15mm, welding wood is allowed to move, knock welding parts. 3, surface porosity: the electrode is baked according to the specified temperature and time, the welding area must be cleaned up, the welding process to choose the appropriate welding current, reduce the welding speed, so that the gas in the molten pool completely escape. 4, welding seam slag: multi-layer welding should be layers of welding slag clean, operation should be correct, arc length appropriate. Pay attention to the flow direction of slag, the use of alkaline electrode, the slag must be left behind the slag. Five, quality records This process standard shall have the following quality records: 1. Welding material quality certificate. 2. Welder certificate and serial number. 3. Welding process test report. 4. Welding quality inspection report and flaw detection report. 5. Record of design change and negotiation. 6. Concealed works acceptance record. 7. Other technical documents.铜焊丝,Copper Welding Rods,铝焊丝,aluminium welding wire,镍焊条,Nickel electrode,药皮焊条,Flux Coated Brazing Welding Rods