IMPACT PROPERTIES OF A LAMINATED COMPOSITE BASED ON ULTRAHIGH CARBON-STEEL AND HADFIELD MANGANESE STEEL

The V-notch impact properties of a laminated composite based on ultrahigh carbon steel (UHCS) and Hadfield manganese steel (HMS) were investigated in the temperature range - 196 to 25-degrees-C. The impact properties were evaluated after heat treatment above the A1 transformation temperature of the ultrahigh carbon steel. The laminated composite exhibits a DBTT of - 100-degrees-C which is lower than either of the monolithic steels that make up the laminate. This is a result of notch blunting from two sources; one source is delamination at the laminate interfaces, and the other source is plastic flow in the HMS matrix. A selectively heat treated laminated composite with very hard UHCS layers (R(c) = 66) and soft HMS layers (R(c) = 17) exhibits a good notch impact toughness of 51J at room temperature. This is attributed to crack blunting by the tough HMS layers and to cracking of the UHCS layers during impact.