Abstract: | Non-quenched and tempered (NQT) steels have been applied for auto forging products at the aim of lower cost since 1980’s in China.Without quenching and tempering processes,the cost of heat treatment was greatly decreased,so they are widely applied in car forgings such as crankshaft,connecting rod.Recently,with the aim of improving performance and reducing production cost,new technologies,such as:reductions of microalloyed elements,microstructure refining,and mechanical properties forecast have been developed in China auto industry.The designation,processing,properties prediction and microstructure of auto components have been controlled comprehensively.With the development of new technologies,NQT steel gradually began to be applied to product important parts,and replace Quenching and Tempering (QT) steels.Both steel makers and end product users are expressed their desire to share benefits of technological innovation.The technologies will have a huge developing space and very bright developing prospects in motor parts industry in future. |