Impact of quench severity and hardness on AISI 4137 using eco-friendly quenchants as industrial heat treatment

The rate of heat extraction, hardness, and severity of quenching of both edible and non- edible bioquenchants for industrial heat treatment was investigated using AISI 4137 medium carbon steel. Results showed that both the maximum and minimum cooling rates occurred in the nucleate boiling stage and were strongly dependent on the viscosity and saponification number. The peak cooling rates of Jatropha oil, groundnut oil, melon oil, sheabutter oil, palmkernel oil, and palm oil were greater than that of mineral oil. The quench severities of Jatropha, sheabutter, and groundnut oil are higher with an H-factor of 5.93, 6.00, and 6.14, respectively. High heat transfer coefficient of 1583, 1180, and 1024 W/m2K were obtained for Jatropha oil, groundnut oil, and melon oilwhereas sheabutter oil, palmkernel oil, palm oil, and mineral oil have heat transfer coefficient of 1001, 971, 828, and 589 W/m2K, respectively. For all the quenchants, the hardness of steel is increased with an increase in the austenite heating temperature