Development of Severe Deformation/Non-Transformation Process Utilizing Friction Stir Processing

对不同碳含量的碳钢进行搅拌摩擦焊，包括A_1点以下和A_1点以上（共析温度723℃）的过共析钢。高碳钢A_1接头的显微组织主要为马氏体。因此，拉伸试验结果是分散的。而A_1以下接头的显微组织则由铁素体和球状铁素体组成。A_1以下接头的小摆锤冲击吸收能量提高了3倍。

Friction stir welding was performed for carbon steel with different carbon contents including hyper eutectoid steel below and above the A_1 point (eutectoid temperature 723℃). The microstructures of the above A_1 joints mainly consist of martensite for higher carbon steels. Therefore, the tensile tests results are scattered. On the other hand, the microstructures of the below A_1 joints consist of a ferrite with globular cementite. The absorbed energy for the small Charpy impact test is increased for the below A_1 joints by three times.