Increased hardness value due to the diffusion of low-temperature carburizing process

Nitha .; Onny S Sutresman; Ahmad Yusran Aminy; Lukmanul Hakim Arma

doi:10.25042/epi-ije.022023.03

Nitha . Mechanical Engineering Department, Hasanuddin University
Onny S Sutresman Mechanical Engineering Department, Indonesian Christian Toraja University
Ahmad Yusran Aminy Mechanical Engineering Department, Hasanuddin University
Lukmanul Hakim Arma Mechanical Engineering Department, Hasanuddin University

DOI: https://doi.org/10.25042/epi-ije.022023.03

Keywords: carburizing, low temperature, buffalo bone charcoal, hardness, tensile load

Abstract

This research to determine the effect of the tensile load on the carburizing process and the heating temperature lower than the normal carburizing temperature on the hardness of carbon steel with a percentage of 80% buffalo bone charcoal and 20% BaCO₃, 20 mesh grain size, 4 hours holding time, and slow cooling with a tensile load of 1/4σ_p 1/2σ_p 3/4σ_p, and σ_p (proportional stress). The heating temperatures below normal carburizing temperatures, namely 600⁰C, 650⁰C, 700⁰C, and 750⁰C while being pulled by 1/4σ_p, 1/2σ_p, 3/4σp, and σ_p. After reaching the heating temperature, the material is held in the furnace for 4 hours and cooled slowly. After the material is cold, mechanical testing is carried out with Vickers microhardness. Hardness value at a temperature of 600⁰C is 103.93 HRB, at a temperature of 650⁰C is 104.33 HRB, at a temperature of 700⁰C is 104.80 HRB, and at a temperature of 750⁰C is 106.60 HRB, while the process of pack carburizing without tensile at a heating temperature of 800⁰C is 105.2 HRB. This proves that the application of loads at lower heating temperatures during the heating process can exceed the hardness value without tensile loads at higher temperatures of 800⁰ C.