Hardness Distribution and Effective Case Depth of Low Carbon Steel after Pack Carburizing Process under Different Carburizer

Abstract

This research is concerned with the effect of different carburizers on hardness distribution, effective case depth and microstructure of low carbon steel after pack carburizing process. Carburizers to be used were combination of energizer (BaCO3), goat bone charcoal and bamboo charcoal with five different compositions. The specimens were heated to temperature of 950°C, soaked at the temperature for 4 hours and quenched in the water. After the process, microstructures of specimen were observed, the hardness was measured using Vikers method and effective case depths were calculated. The results obtained showed that for all types of carburizer used, the hardness were scattered from surface to the core with lower hardness level. Carburizer composition of 20% BaCO3 + 80% goat bone charcoal produced the highest hardness ( 789.273 HV1) at 0.2 mm from the surface, however, it yielded the lowest effective case depth (0.52 mm). The highest effective case depth of 1 mm was obtained using carburizer composition of 20% BaCO3 + 60% goat bone charcoal + 20% bamboo charcoal. Meanwhile, the original structures of raw material which consist of ferrite and pearlite transformed to hard martensite constituent in the surface after pack carburizing.

Effective Case Depth and Wear Resistance of Pack Carburized SCM 420 Steel Processed Using Different Concentrations of Natural Shell Waste Powders and Carburizing Duration

“…Various carbonates are used as energizers in the carburizing process; barium carbonate (BaCO 3 ), sodium carbonate (NaCO 3 ), and calcium carbonate (CaCO 3 ) are notable examples. These are combined with the carbonaceous material in various percentages [16][17][18][19][20][21][22]. In recent years, calcium carbonate from some industrial waste such as fly ash, slag, and other hot raw material has been used for steel processing.…”

Mechanical Properties of Pack Carburized SCM 420 Steel Processed Using Natural Shell Powders and Extended Carburization Time

“…Many different materials can be used as the carbon source in the pack carburizing process, including barium carbonate (BaCO 3 ), sodium carbonate (NaCO 3 ), and charcoal [19][20][21][22][23][24][25]. In addition, various shells and bones have been considered as the energizing source for carburization.…”