Development of 0.2%C Low Alloyed Steel Hardened by Copper Precipitation

Steels hardened by copper precipitation are in focus of many research programmes. Most of effort is devoted to development of low-carbon steels. Precipitation strengthening of ferrite is used for steel strengthening without losing capability of deep drawing before the precipitation hardening.

This article shows results of precipitation strengthening in low alloyed steel with 0.2% carbon. The steel composition aims to develop weldable high-strength steel for demanding structural applications. Controlled hot rolling was used to refine the steel structure. Quenching and ageing for copper precipitation was performed. Mechanical properties and microstructure were compared after different ageing time and duration. Tensile tests were performed and a hardness was measured. Copper precipitation upon ageing was documented by FEG SEM microscopy. Integral material response was recorded by dilatometric measurement.