The microalloying elements are sometimes used in combination with other strengtheners such as boron, molybdenum and chromium, nickel and copper, and their use is always accompanied by strict control of impurities such as sulfur, oxygen, nitrogen and phosphorus. By using a controlled cooling process after hot forging, micro-alloyed steel can achieve tensile strength range from 800 MPa to 1200 MPa, and thus micro-alloyed steel is gaining popularity replacing low alloy steel that needs to be quenched and tempered to improve its strength. Also, by eliminating the need for heat treatment, problems associating with heat treatment such as distortion and quench cracking are eliminated as well.