Sa210 Boiler Tube Protection Using High Rpm Stirring Process

Abstract

SA 210 steel have found their applications in several fields ranging from the thermal sector to large boiler industries However, low carbon steels are known to have inferior properties owing to its lower carbon content. Therefore, several processing techniques have been explored in an attempt to improve their mechanical properties. Friction Stir Processing (FSP) is an evolving method which has been specifically developed in order to modify surfaces by the help of grain refinement which is induced by means of deformation and recrystallization of the grains. In this study, FSP was done on bared boiler steel for the improvement of microstructural and mechanical properties. For the present study, plunge depth of 1 mm, feed as 10 mm/min and tool of 1200rpm, and 1700 rpm respectively with 03 passes. Surface enhancement with improved tensile strength and hardness was achieved by recrystallization of grains and severe plastic deformation. The base grain size 25 μm have been dwindled to 8.3 μm, and 6.2 μm respectively with higher rpm. The hardness of processed 1200 and 1700rpm samples by a factor of 3 and 4.03 in comparison to bare steel. The UTS was enhanced by 1.13% and 1.04% respectively w.r.t bare metal.