Formation of nanograin in IF steels by friction stir processing

An IF steel was subjected to friction stir processing using a carbidetungsten pin with the diameter of 16 mm. The rotating speed of pin was 1600rpm, whereas, the applied traverse speed was 31.5mm/min. The specimens were water quenched immediately after the FSP. The results show that the FSP of IF steel resulted in the formation of a 30-35 μm thick surface layer with the nanograins of 50-125 nm. There was a continuous decrease in the hardness from the nanograin surface layer towards the center of specimen. There was almost a three-fold increase in the hardness.

Keywords:

Nanograin IF steel , Nanostructure materials , FSP