For Q235B low carbon steel, the welding temperature is controlled at 1250~1460℃, which can meet the requirements of penetration of wall thickness of 3~5mm. In addition, the welding temperature can also be achieved by adjusting the welding speed.
When the input heat is insufficient, the edge of the heated weld cannot reach the welding temperature, and the metal structure remains solid, forming unfused or incomplete penetration; when the input heat is insufficient, the edge of the heated Q235B steel plate weld exceeds the welding temperature , Produce overburning or droplets, so that the welds form molten holes.
After the edge of the Q235B steel plate is heated to the welding temperature, under the extrusion of the squeeze roller, a common metal crystal grain will infiltrate and crystallize each other, and finally a firm weld will be formed. If the extrusion force of the Q235B steel plate is too small, the number of common crystals formed will be small.
The strength of the weld metal of the Q235B steel plate decreases and cracks occur after the force is applied. If the extrusion force of the Q235B steel plate is too large, the molten metal will be squeezed out of the weld, which not only reduces the strength of the Q235B steel plate weld, but also Produce a large number of internal and external burrs, and even cause defects such as welding overlap.
