Impact of hardening techniques on the mechanical properties and hardness of mercury steel with varying diameters

The mechanical properties and hardness of steel are influenced by both the diameter of the steel and the type of hardening applied. The present study examined mercury steel samples with diameters of 3 mm, 4 mm, and 5 mm that underwent heat treatment using two methods: water quenching and oil quenching. The heat treatment process comprises four distinct stages: annealing, stress relieving, hardening, and tempering. Tensile, bending, and hardness tests were conducted on both heat-treated and untreated samples. Tensile and bending tests were performed using a Shimadzu AGX Plus testing machine with a load capacity of 100 kN, while the hardness tests utilised a Vickers hardness tester. The findings revealed that the greatest increases in tensile strength, bending strength, and hardness occurred in the samples that were quenched in water. However, these water-quenched samples also exhibited high levels of brittleness. Conversely, the oil-quenched samples exhibited a substantially diminished propensity for brittleness.