In welding practice teaching, students practice in arc welding operation, often weld, burn, incomplete penetration, concave, slag, forming defects such as poor, analyzing the causes of these defects, mainly students in the welding operation and failing to observe the changes in bath temperature, there is no effective control of bath temperature and the above-mentioned defects.

Bath temperature, directly affect the quality of Copper Alloy Welding Wire, bath temperature is high, large pool, hot metal flow is good, easy-to-fusion, but too high, the molten iron under the drip easily, forming the back side welding easy to burn, to form weld, shape is also difficult to control, and the plastic connector down, bend easy to crack. Bath temperature is low, a smaller pool, hot metal dark, poor mobility, easy to produce incomplete penetration, lack of fusion, slag and other defects.

Bath temperature and the welding current, electrode diameter, electrode angle, arc burning time has a close relationship, take the following measures for the relevant factors to control the bath temperature.

1, the welding current and electrode diameter: According to the spatial location of the weld, solder level in the selection of the welding current and electrode diameter, open welding, the welding current and electrode selection of large diameter, vertical, horizontal Yang bit smaller. Such as the 12mm flat butt-welding of the closure of the bottom electrode selection φ3.2mm, welding current :80-85A, filling, cover the electrode surface used φ4.0mm, welding current :165-175A, a reasonable choice of welding current and electrode diameter, easy to control bath temperature, is the basis of weld.

2, the operation of the method, circle-shaped bath temperature operation of the transport of temperature higher than the crescent-shaped, crescent-shaped transport of temperature was higher than the zigzag operation of the bath temperature, seal welded in 12mm flat bottom, using the operation of the zigzag and with the magnitude of the swing and groove on both sides of the pause, effective control of the bath temperature, so basically the same size fuse hole, the roots do not form a groove weld and decrease the chances of burn, there is no penetration improved, so that almost flat plate welded butt welding double-sided shape is no longer difficult.

3, electrode angle, the angle between the electrode and the welding direction at 90 degrees, the arc concentration, bath temperature is high, the angle is small, arc scattered, low bath temperature, such as the 12mm flat bottom seal welding, welding angle: 50 - 70 degrees, the bath temperature has dropped, to avoid the back of the resulting weld or from high. Again, in the 12mm bottom plate for vertical welding rod seal, the joints of the electrodes used angle of 90-95 degrees, the bath temperature is rapidly increasing, smooth melt holes open, the back forming a more smooth, effective control of the connection point within concave phenomenon.

4, the arc burning time, φ57 × 3.5 pipe fixed horizontal and vertical fixed welding practice teaching, the use of off-arc method of Welding Wire China, seal welding the bottom, off the arc and arc burning time frequency directly affects the bath temperature, as wall is thin, the limited capacity of the arc heat, slow down if the bath temperature to reduce the frequency arc, easy to produce shrinkage, therefore, can only be used to control the arc burning time of bath temperature, if the bath temperature is too high, melting hole is large, the arc burning time can be reduced, so that lower bath temperature, time, melting holes smaller internal tube forming medium height, to avoid internal weld pipe welding or produce ultra-high tumors.

In summary, the welding practice teaching, students learn to observe the changes in bath temperature, effective control of weld pool temperature control method, is to learn basic welding technology, to lay the solid foundation in order to achieve a breakthrough, in order to become a outstanding work of welding technology