backing gas的意思|示意

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Backing gas is a type of gas commonly used in welding process, which affects the nature of the weld to a certain extent. In welding, it is generally used as an assist gas.

The backing gas is mainly used to protect the back of the weld pool. Since the back of the weld pool is not exposed to the arc, the temperature of the back of the weld pool is low, and the molten metal on the back is easy to solidify, resulting in porosity and other defects. The role of the backing gas is to protect the back of the weld pool from oxidation, thus reducing defects.

Generally, an inert gas is used as the backing gas. The commonly used inert gas is argon and helium. The choice of backing gas depends on the welding process, material, size of the weld, and the welding characteristics of the material.

The backing gas should be as uniform as possible, and the air flow should be smooth and even. When using the backing gas, it is necessary to properly adjust the flow rate, in order to balance the flow rate between the protection gas and the welding power. Generally, the flow rate of the protector gas should be slightly larger than the welding power, and the total flow rate of the gas should not exceed 20L/min.

In the welding process, it is necessary to pay attention to the use of the backing gas, in order to ensure the quality of the weld and reduce the defects of the weld.