1. Complete annealing: Complete annealing is a heat treatment process in which the steel is heated to 20-30℃ above AC3, kept warm for a long enough time, and then slowly cooled with the furnace to obtain a near-equilibrium structure. It is mainly used in hypoeutectoid steel, and its purpose is to refine the grains, eliminate internal stress and work hardening, improve plastic toughness, make the chemical composition and structure of the steel uniform, improve the cutting performance of the steel, and eliminate defects such as Widmanstätten structure and banded structure in medium-carbon structural steel.
2. Incomplete annealing: Incomplete annealing is a heat treatment process in which the steel is heated to between AC1-AC3 (hypoeutectoid steel) or AC1-ACcm (hypereutectoid steel), kept warm for a certain period of time, and then slowly cooled with the furnace to obtain a near-equilibrium structure. For hypoeutectoid steel, if the original structure distribution of the steel is appropriate, incomplete annealing can be used instead of complete annealing to eliminate internal stress and reduce hardness. For hypereutectoid steel, incomplete annealing is mainly to obtain spherical pearlite structure to eliminate internal stress, reduce hardness, and improve cutting performance.
3.Spheroidizing annealing: Spheroidizing annealing is a heat treatment process that spheroidizes carbides in steel to obtain granular pearlite. It is mainly used for eutectoid steel, hypereutectoid steel and alloy tool 3 steel. Its purpose is to reduce hardness, improve cutting performance, uniform organization, and prepare for quenching.
Seamless Pressure Pipe
