steel welding engineering

Hainan Steel teach you: steel welding engineering

(A) material quality requirements
(1) Hainan steel welding works with a welding rod, wire, flux, electroslag weld mouth, studs, welding porcelain ring and shielding gas welding, etc. must be used with a factory quality certification, quality inspection reports and other documents.
(2) Hainan steel welding engineering, the general principles of the weld metal and base the selection of materials, such as strength of welding rod, wire, solder and other welding materials.
(3) welding, flux cored wire, electroslag weld mouth and studs with ceramic ring before use, must be baked in accordance with the provisions of the product description and related welding processes.
(Ii) quality control during construction
(1) When the welding operations ambient temperature is below 0 ℃ but not lower than -10 ℃, welded joints and welding surface should be in each direction is greater than or equal to 2 times the plate thickness range of not less than 100mm is heated to not lower than 20 ℃ After the minimum preheat temperature specified above and before welding, and the welding process should not be below this temperature.
Room (2) pre-heating and temperature control channels should adopt electric heating, flame heating and infrared heating plus heat method, and using special thermometer measurements. Preheat the welding area should be heated on both sides of the groove width of more than 1.5 times the thickness of the weldment welding, and not less than 100mm. Temperature measurement point, when non-members should be on the back of an enclosed space heating surface in the weldment from both sides of the weld groove at not less than 75mm, when the member is a closed space should be in the front side from the weld groove at not less than 100mm. When the process of selection of the preheating temperature is below the minimum specification requirements should be determined by the procedure qualification test.
(3) non-sparking arc welds on the base metal outside the area. In the groove arc welding a local area should not be leaving the crater. When the arc plate, lead plate and spacer plate when the steel should be used in the yield strength of not more than the nominal strength steel is welded steel, and weldability similar.
(4) The multilayer welds should be continuous welding, weld bead after each layer should be cleared up.
(5) Such as design documents or the contract documents required butt eliminate stress, the structure of the tensile stress fatigue check node butt or weld-intensive, member, should adopt the electric heater and partial annealing furnace annealing overall and other methods of stress relief treatment; if only stable structure size, vibration method can be used to eliminate stress.
(6) with a hammer method to eliminate intermediate solder layer stress, you should use the network first hand hammer or a small vibrating tool, should not be the root of the weld, the weld cap weld or bevel edge of the base material hammer.
(7) carbon steel welds should be cooled to ambient temperature, low-alloy steel should be after the completion of the welding seam 24h NDT testing.
(8) checks should be carried out after bending test weld stud welding, stud weld and heat affected zone bend 30 ° after there is no visible cracks.
(9) the repair welds should be continuous welded parts, should be taken if an interrupt after welding heat insulation measures to prevent cracks; repairing defects in the weld of the same parts of the number should not be more than twice the area of ​​welded joints should be increased after the repair powder or colored checks.