Microstructure and property evolution of the 1538MV non-quenched and tempered steel for a crankshaft during the forging process

The microstructure, properties and precipitation of rolled bars and a crankshaft were studied with experiments and numerical simulations.Compared with the rolled bars, the microstructure of the crankshaft was coarsened, and the volume fraction of ferrite decreased because of the uneven strain, the metal flow and the fast cooling rate during the forging process.The main precipitation in ferrite involved V (C, N) particles, which became more dispersed after the forging.As a result, the strength of the crankshaft was higher than that of the rolled bars, while the plasticity was lower.The results provided some additional information about the quality improvement of rolled bars and the basis for optimizing the crankshaft-forging process.