Aluminum Composited Panel and other aluminum profiles in the melting temperature control
Aluminum Composited Panel and other aluminum profiles in the smelting process must have a high enough temperature to ensure that the aluminum Composited Panel and other metal elements fully melted and dissolved. Heating temperature is too high, the melting speed is faster, but also make the metal and furnace gas, lining and other harmful effects of each other shortened. Production practice shows that rapid heating to accelerate the melting of the charge, shorten the melting time, to improve productivity and quality are beneficial.
On the other hand, the excessively high temperature of the Aluminum Composited Panel is prone to overheating, especially when using a flame reverberation furnace, the artillery is in direct contact with the charge and is strongly added to the molten or semi-molten metal, Melt. At the same time, the higher the temperature, the metal and furnace gas, lining and other interaction of the reaction is also carried out faster, it will cause the loss of metal and melt quality reduction. Overheating is not only easy to absorb a large amount of gas, but also easy to make in the Aluminum Composited Panel solidification of the ingot after the grain structure is coarse, increasing the tendency of the ingot crack, affecting alloy performance. Therefore, in the smelting operation, should control the melting temperature, prevent the melt overheating.
But the aluminum Composited Panel is too low in the production practice is meaningless. Therefore, in the actual production, it is necessary to prevent the melt overheating, but also to accelerate the melting, shorten the melting time. The control of melting temperature is extremely important. Most of the plants are rapidly melted at high temperature after rapid addition, allowing the metal in semi-solid, semi-liquid state to be exposed to strong furnace gas and flame for a short period of time to reduce metal oxidation, burn and reduce melt gas. When a layer of liquid metal appears in the furnace, in order to reduce the local overheating of the melt, the melting temperature should be appropriately reduced and agitated during the smelting process to facilitate the heat transfer of the melt. In particular, to control the aluminum Composited Panel charge R will melt all the melting temperature. Due to metal or alloy melting latent heat, when the charge all the melting temperature after the rise, this time if the melting temperature control is too high to cause the entire pool of metal overheating. In production practice, the occurrence of melt overheating is mostly caused by poor temperature control in this case.
The actual choice of melting temperature, theoretically should be based on a variety of different aluminum Composited Panel and other alloy elements to determine the melting point temperature. Different alloys have different melting points, ie, alloys of different compositions, where the temperature at which the solid begins to melt is called the solidus temperature and the temperature at which all melts (called the liquidus temperature) is different. In these two temperature ranges, the metal is in a semi-liquid semi-solid state.
Aluminum Composited Panel in the welding process will be what causes the cracks, how we can effectively prevent the aluminum Composited Panel welding process in the welding cracks and deformation, we have taken from the production process the following measures,
(1) the choice of electrodes: the choice of a high crack resistance of the electrode, is conducive to reducing the tendency of cracks in the weld.
(2) welding groove: two different thickness plate stitching, in order to weld the weld can be a smooth transition, must be in the thick plate on the open 6 × 35 ° groove.
(3) preheating: the higher the strength level of steel, the greater the tendency to quench, the need for preheating. Proper selection of preheat and postheat systems helps to improve the microstructures and stress states of welded joints, thereby effectively improving the resistance to cold cracking. For the structural steel of the Aluminum Composited Panel, it is necessary to preheat the process. For the structural parts of the butt joint, the heating width on each side shall not be less than 5 times the thickness of the plate. In the aluminum Composited Panel welding, the need for two steel plate welding preheating, preheating area for the groove on both sides of 75 ~ 100mm range, preheating temperature of 200 ~ 350 ℃.
(4) positioning welding: In order to ensure the formation of docking joints and can penetrate, in the welding of two steel plate flat on the table, keep the gap 1mm, and welding fixture will be pressed on the platform, warm immediately after positioning Welding (spot welding), as shown in Figure 1.
(5) full welding: In order to make the weld and heat affected zone slow cooling, reduce the tendency to crack, should be short-distance welding method, that is, a long weld segment welding, so that each section of the weld Repeated heating in a short time. Aluminum Composited Panel welding, the use of short-track jump welding method, each section of the length of 150 ~ 200mm.