Understand the principle of molten pool
A weld with beautiful appearance and excellent quality is achieved by the welder controlling the welding pool according to the process card and reasonable skills. Welders are required to fully understand the temperature field of the molten pool and the arc transition principle.
Generally, the temperature of the weld pool is basically the highest in the center of the molten pool. The molten iron has good fluidity. The temperatures on both sides and the back gradually decrease. According to this principle, the temperature field of the welding pool changes. According to this principle, it can be analyzed that the arc molten pool is also moving. Moved by 1-2-3-4-N.
Since the arc frequently passes through the center of the weld pool, the heat is highest in the middle of the molten pool, so the molten iron feels thinner in the middle. If 1-2-3-4-N moves at a constant speed, the middle of the weld will bulge and the two sides will not be full. , resulting in defects such as excess weld height and undercuts on both sides.
According to this principle, when manual welding, welders must avoid the uniform movement of the arc in the weld. It is generally required to pause on both sides of the weld and make a rapid transition in the middle to balance the heat of the molten pool, thereby controlling the quality of the weld and beautiful appearance.