The effects of pack carburizing using charcoal of unused mahogany on fatigue characteristic of v-notch shaft steel specimens

Abstract

The aim of this research is to study the fatigue characteristic of v-notch shaft steel specimens before and after pack carburizing. The carbon source is taken from charcoal of unused mahogany. The fatigue test is conducted on rotary bending machine. The specimens are made of low carbon steel of 0.17% carbon content. Pack carburizing is conducted to the specimens at 930°C. V-notch is made to present the stress concentration factor on the specimens. To see the effects of the carburizing in changing the material properties, micro-structures before and after carburizingare looked and micro hardness measurements along the cross sectional area are carried out. The results show that the carburizing process increases fatigue strength of the material. The micro-structures of the raw material are ferrite and pearlite. The carburized material is divided into two zones i.e. surface zone and core zone. The surface zone consists of hypereutectoid, eutectoid, and hypoeutectoid sub-zone. The core zone is the same as raw material