First, what is the hardness of cold-rolled steel plates:
1. Ordinary cold-rolled steel plates: The hardness range of ordinary cold-rolled steel plates is generally between HRB1/2H=74~89 and 1/4H=65~80. Among them, HRB refers to Rockwell hardness, which is a standard for measuring the hardness of materials. The higher the value, the harder the material. 1/2H and 1/4H refer to the position of the hardness test. 1/2H means testing at half the thickness of the steel plate, and 1/4H means testing at one-quarter the thickness of the steel plate.
Ordinary cold-rolled steel plates are mainly used in the construction, automobile, home appliance, and other industries. They are required to have certain strength and hardness, as well as good plasticity and toughness. In the construction field, ordinary cold-rolled steel plates can be used to make light steel structures, exterior wall panels, and roofs of high-rise buildings, etc.; in the home appliance industry, they can be used to make the outer shells and internal structural parts of household appliances such as refrigerators and washing machines; in the automotive field, they can be used to make body structural parts, frames, etc.
2. Deep-drawn cold-rolled steel plate: Deep-drawn cold-rolled steel plate is a cold-rolled steel plate that has been processed by a deep-drawing process, with higher strength and hardness, as well as better plasticity and toughness. Its hardness range is generally between HRB1/2H=85~95 and 1/4H=70~80. Deep-drawn cold-rolled steel plate is mainly used to make parts that require high strength, high hardness, and good plasticity, such as automobile bodies, electrical housings, etc. Since deep-drawn cold-rolled steel plate is processed by deep-drawing process, it can obtain a finer grain structure and higher strength, so it has better-forming performance and impact resistance.
3. Ultra-deep-drawn cold-rolled steel plate: Ultra-deep-drawn cold-rolled steel plate is a cold-rolled steel plate that has been processed by an ultra-deep-drawing process, with higher strength, hardness, better plasticity, and toughness. Its hardness range is generally between HRB1/2H=80~90 and 1/4H=65~75.
Second, how to improve the hardness of cold-rolled steel plates:
The hardness of cold-rolled steel plates can be improved by the following methods
1. Heat treatment: Heat treatment is one of the most common methods to improve the hardness of cold-rolled steel plates. By controlling the heating process and cooling rate of cold-rolled steel plates, the crystal structure and chemical composition of cold-rolled steel plates can be changed, thereby improving the hardness of cold-rolled steel plates. Common heat treatment methods include quenching, tempering, and normalizing.
2. Surface treatment: Surface treatment is to increase the hardness of cold-rolled steel plates by adding a layer of harder material to the surface of cold-rolled steel plates. Common surface treatment methods include flame spraying, sandblasting, and painting. These surface treatment methods can make the surface of cold-rolled steel plates smoother and improve the hardness and corrosion resistance of cold-rolled steel plates.
3. Chemical treatment: Chemical treatment is to increase the hardness of cold-rolled steel plates by adding a layer of chemical substances to the surface of cold-rolled steel plates. Common chemical treatment methods include nitriding, hydrogen treatment, and carbonitriding. These chemical treatment methods can significantly improve the hardness of cold-rolled steel plates and can form a protective layer with higher hardness and stronger corrosion resistance on the surface of cold-rolled steel plates.
Post time: Jan-22-2025