Effects of induction hardening and prior cold work on a microalloyed medium carbon steel

The torsional strength and microstructural response to induction hardening of a 10V45 steel with prior cold work was evaluated. The vanadium-microallo yed 1045 (10V45) steel was characterized in three conditions: as-hot-rolled , 18% cold-reduced, and 29% cold-reduced. Two of these evaluations, 10V45 a s-hot-rolled and 10V45-18%, were subjected to stationary and progressive in duction hardening to three nominal case depths: 2, 4, and 6 mm, All specime ns were subsequently furnace tempered at 190 degrees C for 1 h, The martens itic case microstructures contained residual lamellar carbides due to incom plete dissolution of the pearlitic carbides in the prior microstructure. To rsional overload strength, as measured by maximum torque capacity, is great ly increased by increasing case depth, anti to a lesser extent by increasin g prior cold work level. Maximum torque capacity ranges from 2520 to 3170 N . m, depending upon induction hardening processing. Changing induction har dening processing from stationary (single-shot) to progressive (scan) had l ittle effect on torque capacity.