Bath temperature, directly affects the quality of welding, high temperature bath, large pool, hot metal flow, and easy to weld, but too high, the molten iron is easy under the drip, forming the back side welding easy to burn, the formation of weld, shape is also difficult to control, and the plastic connector down, bending easy to crack. Low bath temperature, bath small, molten 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. Diameter 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 larger diameter, vertical, horizontal Yang bit smaller. Such as the 12mm plate 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 Stainless Steel Welding Wires current and electrode diameter, easy to control the bath temperature, is the basis for forming the weld. Method 2, operation of the method, circle-shaped bath temperature operation of the transport of temperature higher than the crescent-shaped, crescent-shaped operation of the temperature was higher than the zigzag operation of the bath temperature, the 12mm flat bottom welded closed, operation of the use of serrated and with the magnitude of the swing and groove on both sides of the pause, effective control of the bath temperature, so that basically the same size fuse hole, the roots do not form a welding groove tumor and decrease the chances of burn, there is lack of penetration improved, so that almost single-sided plate butt-welding of the weld shape is no longer a difficult double. Angle 3, electrode angle, the angle between the electrode and the welding direction at 90 degrees, the arc focus, high bath temperature, a small angle, 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 weld resulting from the tumor or high. Again, the 12mm bottom cover plate for vertical Welding Electrode, the connector rod used 90-95 degree angle, so that rapid increase in bath temperature, the smooth melting holes open, the back forming a more smooth and effective control of the joint point of concave phenomenon. Time 4, the arc burning time, φ57 × 3.5 tube fixed horizontal and vertical fixed welding practice teaching, the use of off-arc welding method, seal the bottom welding, arc fault and arc burning time, the frequency directly affects the bath temperature, as wall thin, arc heat capacity is limited, if slowed down to reduce the frequency arc bath temperature, easy to produce shrinkage, therefore, can only be used to control the arc burning time, bath temperature, if the bath temperature is too high, melt the hole is large, can reduce the arc burning time, the bath temperature decreases, then, melting the hole smaller, the tube forming a high degree of internal medium, to avoid the internal pipe welding seam or produce ultra-high tumor.
Do welding, the welder must be applied pieces of material, welding equipment, welding materials used in the performance and the performance have to understand, and make the appropriate option to ensure the welding quality of the product. Usually based on the chemical composition of steel, mechanical properties, crack resistance, etc., and the shape of welded structures, working conditions, the force and welding equipment and so on. Into account, if necessary, need to test to determine the Welding Electrode and used process measures to be taken. 1, mild steel welding in accordance with the general strength of the steel grade to choose the appropriate electrode. Also need to steel welding according to the base metal composition of the transition, welded structure, size, shape, groove, and the force and other effects, a comprehensive consideration. Higher cooling rate in the weld, the increased strength of welded joints prone to crack under adverse circumstances, often the choice of low intensity level than the base metal electrode. In case of thick multi-layer welding or soldering treatment after normalizing the situation, you need to weld strength is too low to prevent the phenomenon. 2, the same intensity level of acidity or alkaline welding rod selection, depending on the structure of welded shape (simple or complex), plate thickness (stiffness of the small or large), working conditions (static load or dynamic load) and steel crack resistance and so on. Usually requires a good plasticity, high toughness, high temperature performance, strong anti-cracking, use alkaline electrode. Such as the DC power supply difficulties, the choice of AC and DC welding material. 3, for low-carbon steel and low alloy steel welded joints between dissimilar steels is generally used with a lower strength grade of steel Welding Electrode Manufacturers accordingly. 4, for the welding of carbon steel, due to the higher carbon content steel, increasing the occurrence of weld cracking tendency can use low-hydrogen electrodes or weld metal with good ductility and high toughness electrodes, and take warm-up before welding , slow cooling after welding process measures. 5, for welding steel, carbon steel are generally higher, and the thickness of large, complex shape, easy to produce welding cracks. Especially when the steel contains more alloying elements, it is more prominent, so, in the welding should be special attention. Generally use low-hydrogen electrodes and preheating before welding, and to take appropriate measures such as the welding process. 6, on the shelf for gravity welding low carbon steel and low alloy steel welding, the electrode can be used gravity. 7, the conditions on the use of special steels and welded structures, can use special electrodes. 8, electrode grade listed in the current scope, for reference only. After preheating the workpiece such as the current reduction than the normal 5% to 15%; DC at about 10% smaller than the exchange; Li Yang welding and welding flat welding current is smaller than the 10% to 15%.