What are the three manual welding methods of Q235B steel plate?

Three manual welding methods of Q235B steel plate:

(1) Manual carbon arc welding

The end of the workpiece channel is grooved, and the circumference of the round hole is milled into a single-sided V-shaped groove angle of about 45°, and the groove depth is 3.5 to 4.7mm. The material requirements of the 7 round plugs are the same as that of the wokpiece, and the thickness is 4.9mm. The shape and size of the bevel is the same as the Q235B steel plate. The machining accuracy of the round plugs is required to closely match the water channel. The preheating temperature of Q235B steel plate is 890℃, and the welding power supply adopts DC positive tube to increase the temperature of the workpiece. The welding current is 333A, and the welding tongs are self-made water-cooled welding tongs.

(2) Manual arc welding edge

When the thickness of Q235B steel plate is greater than 4.6mm, it must be preheated before welding, and the preheating temperature is generally about 450-880℃. For welding with XZ-CF56Q235B steel plate, the power supply should adopt DC reverse connection. Short arc should be used when welding, and Q235B steel plate is not suitable for lateral swing. The reciprocating linear motion of Q235B steel plate can improve the weld formation. When welding, the slag between the layers must be completely removed, and the welding should be carried out in a well-ventilated place. After the Q235B steel plate is welded, use a flat-head hammer to strike the weld to eliminate stress and improve the quality of the weld.

(3) Manual argon arc welding

In the manual argon arc welding of Q235B steel plate, the Q235B steel plate used is Q235B steel plate XZ-L76 and Q235B steel plate XZ-PS45. Before welding, the oxide film and oil on the welding edge of the workpiece and the surface of the plate must be cleaned up to avoid defects such as pores and slag inclusion. When the diameter of the joint Q235B steel plate is less than 7mm, in order to avoid incomplete welding, generally no blunt edge is left.