2022

What should be paid attention to when the bimetal backing plate is welded through?

The temperature control of bimetal liner involves many parameters. The excitation frequency is inversely proportional to the square root of capacitance and inductance in the excitation circuit, or is proportional to the square root of voltage and current. The excitation frequency can be changed by changing the capacitance, inductance or voltage and current in the circuit. So as to control the welding temperature.
Why should the cooling process of welded junction be good? Because of the milling of the welding end face of the bimetal backing plate, how to keep the end face clean, and the cooling process and time of the weld junction, these problems may not be shown from the weld junction.
However, the inherent performance of the welded junction cannot be guaranteed. Therefore, the correct and effective implementation of welding procedures and operating procedures is crucial, and is closely related to the stability of welding equipment performance and the sense of responsibility of operators. In terms of electric fusion connection, it is not enough to ensure the stability of the transmission and discharge voltage of the electric fusion plate and the accuracy of the welding time. However, preparations before welding, such as whether the end face of the bimetal composite liner plate to be welded is clean, will definitely affect the welding effect if there are impurities.
If the oxide layer is scraped, not scraped or not scraped enough, it is likely to cause the failure of welding. For low carbon steel, the welding temperature shall be controlled at 1250~1480 ℃, which can meet the requirements of 3~5mm plate wall thickness penetration. In addition, the welding temperature can also be realized by adjusting the welding speed.
When the input heat is insufficient, the heated weld edge cannot reach the welding temperature, and the metal structure remains solid, forming incomplete fusion or incomplete penetration; When the input heat is insufficient, the heated weld edge exceeds the welding temperature, resulting in overburning or droplet, which causes the weld to form a cavity.
After the two edges of the bimetal composite liner slab are heated to the welding temperature, the common metal grains are formed under the extrusion of the extrusion roller to penetrate and crystallize each other, resulting in a solid weld. If the extrusion force is too small, the number of common crystals formed will be small.
The strength of weld metal decreases and cracks will occur after being stressed; If the extrusion force is too large, the molten metal will be extruded from the weld, which will not only reduce the strength of the weld, but also produce a large number of internal and external burrs, and even cause defects such as weld overlap.
Whether the assembly of the electric fusion plate and the bimetal backing plate to be welded is correct will also affect the welding quality. In addition, whether the storage conditions of the electrofusion plate before welding meet the standards and whether the cooling process after welding is proper are all factors affecting the welding quality of the bimetal backing plate.

YONGXIN SPECIAL STEEL

What should be paid attention to when the bimetal backing plate is welded through?