Abstract: As one of the steel types which are most rapidly developed over the recent years and most promising, the miroalloyed steel is so widely employed in various industrial sectors that even the overall technical capacity of a metallurgical enterprise can be demonstrated through the product line, size range, output and quality of his microalloyed steels. Taking advantage of the grain-fining and segregation-enhancing effects by the microalloy elements like Nb, V and Ti, Tianjin Steel Tube Corp., Ltd. has developed hi-strength microalloyed steels with all the actual properties up to the physical level of the similar products made both at home and abroad.