Flash butt welding machine welding operation points and precautions

Rising StarAutomatic flash butt welding machineAlthough the degree of automation is high and the requirements for personnel are not high, some operating points must still be followed to avoid safety accidents.

1) Before welding, you should adjust the transformer stages, turn on the cooling water, and check the components and grounding conditions of the butt welding machine before starting work.

2) Before work and when changing the steel bar grade or diameter, trial welding should be carried out according to relevant regulations, and tensile and cold bending tests should be carried out. Only after passing the test can welding in batches.

3) Before welding, the rust and dirt at the electrode jaws of the steel bar ends should be removed to facilitate the passage of current and prevent "ignition" caused by poor contact at the jaws.

4) The ends of the steel bars should be kept straight. If there are bends and twists, they should be straightened or cut off. The electrode jaws should be fixed firmly and the two steel bars should be in the same straight line. During the welding process, welding slag, rust and other dirt on the electrodes should be removed at any time, and brushing should be done properly at the end of each shift.

5) When preheating flash welding is used for grade II and III steel bars, the key points of operation are: one flash, the flash level shall prevail; sufficient preheating, the frequency should be high; the second flash should be short, stable and strong; the upsetting process should be fast and powerful. For Grade IV steel bars, due to the high carbon, manganese, and silicon content, oxidation defects are easily produced in the weld and heat-affected zone during welding, and they are prone to brittle fracture due to overheating and quenching. When welding, the appropriate temperature should be mastered, and the welding parameters should be adjusted appropriately according to the temperature. The key points of its operation are:One flash is used to remove crushing injuries; the preheating is moderate and the frequency is medium to low; the second flash is steady and strong; the upsetting process is fast and with appropriate force.
When preheating steel bars at low frequency, the preheating contact time should be between 0.5~2s/time according to the grade and diameter of the steel bars. The preheat gap time is slightly larger than the contact time of each preheat.
There should be a certain contact pressure during preheating. The degree of preheating should be controlled by combining the preheating allowance and the number of preheating times.

6) Steel bars of different diameters can be butt welded, but the ratio of the two cross-sectional areas should not be greater than 1.5 times, and the diameter difference should not be greater than 2^~3mm. When welding, the welding parameters should be selected according to the large diameter steel bars.

7) When flash welding is carried out under negative temperature (not less than -20oC) conditions, the welding should be done indoors, weak parameters should be used, the stretch length should be appropriately increased, the number of transformer stages should not be too large, the flash speed should be slightly slower, the number of preheating times should be increased, and the joints should be maintained with asbestos powder and other materials.
8) After welding is completed, the clamp should be released after the joint turns from red to black, and the steel bar should be taken out smoothly to prevent the joint from bending.

Wuxi Xinxing Welding Equipment Factory has been engaged in resistance welding for 29 years. Its core technology products include: semi-automatic butt welding machine, pneumatic-flash butt welding machine, multi-strand wire welding machine, foot spot welding machine, pneumatic spot welding machine, medium frequency spot welding machine, row welding machine mesh welding machine, resistance automatic welding machine, energy storage welding machine, copper rod and aluminum rod disc circular welding machine, auto parts spot welding machine, sheet metal spot welding machine,Home appliance hardware spot welding machine, small electrical appliance spot welding machine, copper bar copper tube welding machine, nut spot welding machine, stainless steel welding machine, foil strip spot welding machine, aluminum spot welding machine, multi-head spot welding machine, bag cage spot welding machine, mesh welding machine, ton barrel frame welding production line, resistance automatic welding machine, brazing machine, diffusion welding machine, projection welding machine, seam welding machine, wire and cable optical cable supporting equipment, etc., more than 300 kinds. If you are interested in our welding equipment, please contact us.