Rational Al amount in chemical composition of UHCS

By means of the phase diagram calculation and experiment analysis, the rational amount of Al as chemical composition in UHCS was studied. The result indicates that temperature A1 goes up as the Al content increases, while lamellar distance in pearlite phase transformation macrostructure decreases and the network carbide decreases. With Al content increasing, Uniphase austenite area decreases or disappears, the liquefaction temperature becomes low, and hot-workability worsens. To sum up, the rational amount of Al to be chosen as about 2.0%(quality fraction) in UHCS with 1.5%(quality fraction) carbon content.