Carbide band saw blades-carbide composite strip
Carbide band saw blades, similar to high-speed steel band saw blades, are annular products made by welding two materials (carbide and spring steel) with different characteristics into composite steel strips through appropriate welding methods, and then undergoing a series of processes such as tooth processing and heat treatment. When the band saw blade cuts materials on a horizontal band saw bed, it performs a 45°~90° torsional circular motion, and is subjected to complex stresses such as periodic stretching, impact, bending and torsion, and has poor service conditions! In order to improve the performance of the product, people have been committed to the production and tooth design of carbide composite steel strips in the research and development of carbide band saw blades. Among them, carbide composite steel strips are the decisive factors affecting the service life and cutting efficiency of carbide band saw blades.
The composite steel strip used to produce carbide band saw blades is mostly made of high-toughness spring steel, and the teeth are made of cylindrical or block-shaped carbide blocks. Cemented carbide is a powder metallurgy material with metallic properties, which is made of refractory metal carbon compounds as a matrix and an appropriate amount of metal or alloy powder as a bonding phase. It is widely used in cutting tools due to its high strength, high hardness, wear resistance, and relatively stable chemical properties.
The production of cemented carbide composite steel strip is the process of welding cemented carbide blocks one by one on the spring steel strip. The quality of the welding joint between cemented carbide and steel is the key to ensuring the quality of cemented carbide composite steel strip. At present, it is difficult to obtain high-quality welding joints by directly fusion welding cemented carbide and steel. This is because the physical properties of cemented carbide and steel are very different.
Three brazing methods
Boya tools band saw blade cutting metal
Electronic beam brazing
Electronic beam welding is not unfamiliar to the saw blade industry, but due to the different characteristics and costs of the materials, carbide band saw blades cannot achieve equal length and continuous welding of two materials like the production of high-speed steel band saw blades and composite steel strips. However, electronic beam welding has the advantages of high heating power density, small deformation after welding, large depth-to-width ratio of welding joints, and wide range of process parameter adjustment.
Laser brazing
Laser brazing is also a high-energy beam welding method. It uses laser as a heat source to heat the brazing material to melt, and uses the high power density of the laser to achieve local or micro-area heating of the welded workpiece. The welding is fast and the heat-affected zone of the joint is small.
High-frequency induction brazing
High-frequency induction brazing relies on the induction coil to provide heat source to the workpiece. It is characterized by fast heating speed, concentrated temperature, effective reduction of overheating and oxidation of carbide, and the ability to observe and freely adjust the brazing process. Therefore, this method is often used to connect materials with good magnetic conductivity such as steel and carbide.
The manufacturing process of cemented carbide composite steel strip is a complicated process. In addition to the influence of process parameters such as welding method, selection of brazing material, welding process, annealing, etc., the groove design of the welding joint, the degree of surface cleaning, the stability of the equipment, the technical level of the operator, etc., will have a great impact on the welding quality.
