1, fusion welding.
The workpieces to be joined are heated to partial melting to form a molten pool, and the molten pool is joined after cooling and solidification. If necessary, fillers can be added to assist. Suitable for pressureless welding of various metals and alloys. Fusion welding, also known as fusion welding, refers to the method of lowering the welded joint to the molten state under the action of high temperature and so on, and completing the welding without adding pressure. It is also one of the most common welding methods.
Fusion welding can be divided into: arc welding, electroslag welding, gas welding, electron beam welding, laser welding and so on. In the process of fusion welding, in order to protect the welding area from air intrusion, it is necessary to fill the welding area with a lot of gases, such as CO and H2.
2, pressure welding.
The welding process must exert pressure on the weldment, which belongs to the processing of various metal materials and some metal materials. Pressure welding refers to the method of applying a certain pressure during welding, also known as pressure welding. Forging welding, contact welding, friction welding, gas pressure welding, cold pressure welding and explosive welding all belong to the category of pressure welding.
Covered electrode arc welding is an arc welding method with manual covered electrode. It is the most widely used and common welding method in production. It uses the arc heat generated between covered electrode and weldment to melt weldment and covered electrode for welding.
3. Brazing.
A metal material with a melting point lower than that of the base metal is used as the solder, and the base metal is wetted by the liquid solder to fill the joint gap, and the welded part is connected by mutual diffusion with the base metal. Suitable for welding of various materials and different metals or heterogeneous materials.
Brazing refers to a welding method in which the solder below the melting point of the weldment and the weldment are heated to the melting temperature of the solder at the same time, and the gap of the solid workpiece is filled with liquid solder to connect the metals. According to the different melting point of solder, brazing can be divided into brazing and soldering.
The brazing deformation is small, and the joint is smooth and beautiful. It is suitable for welding parts made of precise, complex and different materials, such as honeycomb structural plates, turbine blades, cemented carbide tools and printed circuit boards. Before brazing, the workpiece must be carefully processed and strictly cleaned to remove oil stains and excessive oxide films and ensure the assembly clearance of the interface. Clearance is usually required to be between 0.0 1 and 0. 1 mm. ..