The manufacturing process of high-speed steel rolls mainly includes the following steps
1. Melting and casting of high-speed steel
High-speed steel is a high-carbon, high-alloy tool steel with high wear resistance, toughness, and red hardness. The smelting of high-speed steel usually uses an electric arc furnace or induction furnace, and then vacuum treatment or electro-slag remelting is used to improve the purity and uniformity of the steel. The casting of high-speed steel can adopt continuous casting or ingot casting, but attention should be paid to controlling the temperature and cooling rate of the slab to prevent cracks and segregation.
2. Forging and heat treatment of high-speed steel rolls
The forging of high-speed steel rolls requires high temperatures to ensure the plasticity and uniform structure of the rolls. After forging, an annealing treatment is required to eliminate forging stress and structural defects, and improve the toughness and processing performance of the roll. After annealing, quenching and tempering are performed to obtain proper martensite structure and carbide distribution and improve the hardness and wear resistance of the roll.
3. Processing and inspection of high-speed steel rolls.
The processing of high-speed steel rolls mainly includes turning, grinding, boring and other processes to meet the dimensional accuracy and surface quality requirements of the rolls. Pay attention to the selection of appropriate tools, cutting parameters, and coolant during processing to prevent overheating, deformation, and damage to the roll. After processing, the inspection of the rolls should be carried out, including dimension inspection, surface inspection, hardness inspection, metallographic inspection, etc., to ensure that the quality of the rolls meets the standards.
The manufacturing methods of high-speed steel rolls mainly include forging and casting
1. Forged high-speed steel roll
The high-speed steel smelted in an electric furnace is cast into an ingot, and then forged and rolled into shape. This method can improve the quality of high-speed steel, but it cannot solve the problem of carbide segregation, so it is difficult to manufacture large rolls.
2. Cast high-speed steel roll
High-speed steel is cast on a core of ductile iron or structural steel to form a composite roll. This method can produce large hot rolls, but there are problems with carbide segregation and low interface bonding strength.
3. Centrifugal casting high-speed steel roll
The high-speed steel is cast on the core of ductile iron or structural steel under the action of centrifugal force to form a composite roll. This method can reduce carbide segregation, but it needs to control temperature and pressure.
4. Spray-formed high-speed steel roll
The liquid high-speed steel is sprayed into fine droplets and then sprayed onto the surface of the object during the rapid cooling process to form the desired shape. This method can avoid carbide segregation and improve the performance of the roll.
5. Powder-sintered roll
The high-speed steel powder is filled on the core of the structural steel and then subjected to hot isostatic pressing under high temperature and high pressure to form a composite roll. This method can improve the density and uniformity of the roll.