Microalloying technology is a new metallurgical discipline that emerged in the international metallurgical community in the 1970s. Microalloyed steel is a high-tech steel product produced using modern metallurgical production processes. It is made by adding trace amounts (usually less than 0.1% by mass) of strong carbonitride-forming elements (such as niobium, vanadium, titanium, etc.) to ordinary C-Mn steel or low-alloy steel for alloying. The steel is made through a high-purity smelting process (degassing, desulfurization and inclusion morphology control). During the processing, new processes such as controlled rolling/controlled cooling are applied. Through the physical metallurgical process of controlling the grain refinement of steel and carbonitride precipitation strengthening, an engineering structural material with the best mechanical properties such as high strength, high toughness, high weldability, and good formability is obtained in the hot-rolled state - microalloyed steel.
(1) The added carbonitride-forming elements exert their influence on the mechanical properties of steel through dissolution-precipitation behavior during the heating and cooling of steel.
(2) The amount of these elements added is very small, and the strengthening mechanism of steel is mainly fine grain strengthening and precipitation strengthening.
(3) The controlled rolling and controlled cooling process of steel is of great significance to microalloyed steel, and is also the basis for microalloyed steel to be called a new type of low-alloy high-strength steel. Microalloying of steel and controlled rolling and controlled cooling technology complement each other and are important prerequisites for the design and production of microalloyed steel.
Seamless hydraulic tube
