Welded ball processing method

 

Welded ball

Hot press moulding method

Unloading: according to the design requirements, adopt semi-automatic gas cutting, profiling gas cutting, CNC flame gas cutting and other methods to unload the steel plate and cut out the round plate of suitable size, when unloading, it is necessary to reserve the welding shrinkage margin for fabrication and installation as well as the machining margins for cutting, edge planing, milling and so on.

Heating: The blanks are heated uniformly to about 1050°C±50°C in a reflector furnace or resistance furnace after unloading.

Pressing and moulding: Use hydraulic presses and matching convex and concave moulds to press and mould the heated slabs to produce hemispherical shapes. The demoulding temperature should not be lower than 650°C. After the hemisphere is pressed and moulded, the wall thickness should be reduced by not more than 13% and not more than 2.5mm according to the design and specification.

Cutting bevel margin: can be processed on the machine tool or use semi-automatic flame cutting machine to cut the hemisphere, remove the bevel margin, so that the bevel does not leave roots, in order to weld through.

Assembly of two hemispheres and added ribs: when there are stiffening ribs, the rib plate is suitable to use semi-automatic cutting machine or CNC cutting machine for undercutting, and the outer diameter should be reserved for machining allowance. The two hemispheres and the reinforcing rib plate are assembled on the special ball assembly tyre frame, and the shrinkage of the weld should be left when assembling to ensure that the size and roundness of the finished hollow ball after welding are achieved.

Welding: use carbon dioxide gas shielded welding, semi-automatic submerged arc welding machine for multi-layer multi-channel welding of the sphere, until the weld channel welded flat. When welding, it is necessary to rotate the sphere and adjust the welding channel, wire height and welding parameters.

Flaw detection: After the weld passes the appearance inspection, ultrasonic flaw detection is carried out on the ball weld after 24h to ensure that the internal quality of the weld meets the requirements.

Shaping and anticorrosion treatment: Shape the ball after welding, make its surface smooth and flat, no corrugation, local unevenness is not more than 1.0mm, the height of the weld and the outer surface of the ball is flush with the deviation of not more than ±0.5mm, and then carry out the descaling and anticorrosion treatment, such as spraying inorganic zinc-rich zinc coating of alcohol-soluble ethyl orthosilicate.