There are more than 40 metal welding methods, which are mainly divided into three categories: fusion welding, pressure welding and brazing:
Fusion welding is a method of heating the workpiece interface to the melting state during welding and completing welding without pressure. During fusion welding, the heat source quickly heats and melts the interface between the two workpieces to be welded to form a molten pool. The molten pool moves forward with the heat source, forms a continuous weld after cooling, and connects the two workpieces into one.
In the process of fusion welding, if the atmosphere is in direct contact with the high-temperature molten pool, the oxygen in the atmosphere will oxidize metals and various alloy elements. When nitrogen and steam in the atmosphere enter the molten pool, defects such as pores, slag inclusions and cracks will be formed in the weld during subsequent cooling, which will deteriorate the quality and performance of the weld.
In order to improve the welding quality, various protection methods have been developed. For example, gas shielded arc welding is to isolate the atmosphere with argon, carbon dioxide and other gases to protect the arc from oxidation and avoid defects; For another example, when steel is welded, titanium iron powder with high oxygen affinity is added to the electrode coating for deoxidation, which can protect the beneficial elements manganese and silicon in the electrode from oxidation and enter the molten pool, and obtain high-quality weld after cooling.Tubo de acero grueso amoníaco de acero templado estándar astm
Pressure welding is the combination of atoms between two workpieces in the solid state under pressurized conditions, also known as solid-state welding. The commonly used pressure welding process is resistance butt welding. When the current passes through the connecting end of two workpieces, the temperature rises due to great resistance. When heated to the plastic state, it is connected into one under the action of axial pressure.Harga 316 Precio De La Chapa De Acero Inoxidable
The common feature of various pressure welding methods is to apply pressure without filler material in the welding process. Most pressure welding methods, such as diffusion welding, high-frequency welding and cold pressure welding, have no melting process, so there are no problems such as burning of beneficial alloy elements and intrusion of harmful elements into the weld, which simplifies the welding process and improves the welding safety and health conditions. At the same time, because the heating temperature is lower than that of fusion welding and the heating time is shorter, the heat affected zone is small. Many materials that are difficult to be welded by fusion welding can often be pressure welded into high-quality joints with the same strength as the base metal.Fábrica de fabricación de productos de acero inoxidable 202casting