1. Annealing state
The steel is annealed and heat-treated before leaving the factory. This delivery state is called the annealed state. The purpose of annealing is mainly to eliminate and improve the structural defects and internal stress left by the previous process, and to prepare the structure and performance for the subsequent process, alloy structural steel, structural steel with guaranteed hardenability, cold heading steel, bearing steel, tool steel, steel for steam turbine blades, and iron cable-shaped stainless and heat-resistant steels are usually delivered in annealed state.
2. High temperature tempering state
The steel is subjected to high temperature tempering heat treatment before leaving the factory. This delivery state is called the high temperature tempering state. High temperature tempering has a high tempering temperature, which is beneficial to completely eliminate internal stress and improve plasticity and toughness. Carbon structure, alloy steel, and structural steel with guaranteed hardenability can be delivered in high temperature tempering state. Certain martensitic high-strength stainless steels, high-speed tool steels and high-strength alloy steels, due to their high hardenability and the strengthening effect of alloying elements, are often subjected to a high temperature tempering after quenching (or tempering) to make the steel The medium carbides are properly aggregated to obtain a tempered sorbite structure with coarser carbide particles (similar to the spheroidizing annealing structure). Therefore, the steel in this delivery state has good cutting performance.
3. The state of solution treatment
The steel is solution treated before leaving the factory, and this delivery state is called the solution treatment state. This state is mainly suitable for the treatment of austenitic stainless steel materials before they leave the factory. Through solution treatment, a single-phase austenite structure is obtained to improve the toughness and plasticity of the steel, create conditions for further cold working (cold rolling or cold drawing), and also prepare the structure for further precipitation hardening.
