What are the factors that affect the steel strength

What are the factors that affect the steel strength?

1. Temperature affects steel strength
When the temperature rises, the steel strength decreases, and the plasticity and toughness increase. When the temperature reaches about 450-600°C, the steel strength decreases to almost zero, while the plasticity and toughness are very large, and it is easy for hot processing. This temperature is called the hot forging temperature. When it is around 250℃, the steel strength increases, the plasticity and toughness decrease, and the surface of the steel is blue. This phenomenon is called blue brittleness. When it is above 200℃, heat insulation measures shall be taken. As the temperature decreases, the steel strength increases, the plasticity and toughness decrease, and the brittleness increases. It is called low temperature cold brittleness. When the temperature drops to a certain temperature, the brittleness of the steel increases sharply. This temperature point is called the brittle temperature.

2. The production process affects the steel strength
The smelting process mainly controls the chemical composition; the influence of casting is mainly up to the deoxidation method: Mn is used as a deoxidizer for boiling steel, which has fast time, low price, and poor quality; Si used as a deoxidizer for killed steel, which has a slow time, high price, and good quality; The repeated rolling of the steel can make the steel specifications smaller, improve the plasticity of the steel, and at the same time can weld the pores, cracks, looseness and other defects in the steel, make the metal crystal structure dense, the grain refinement, eliminate the fiber structure defects, and make the steel mechanical properties improved. For the same grade of steel, the smaller the thickness or diameter, the higher the steel strength.