Research Paper
Year: 2022 | Month: August | Volume: 9 | Issue: 8 | Pages: 784-792
DOI: https://doi.org/10.52403/ijrr.20220866
Engineering of St 60 Steel for Industrial Use with Tensile Test at PTKI Material Lab
Muslih Nasution
Mechanical Engineering Department, Faculty of Engineering, Universitas Islam Sumatera Utara, Medan, Indonesia
Corresponding Author: Muslih Nasution
ABSTRACT
Steel is an indispensable material in building an industry. In this research one of the engineered steels is St 60 steel; when it is not heated, the hardness is HRc 15.65 at a temperature of 800°C, 900°C, and 1000°C for 0.5 hours The steel is quenched with water (H2O) as a cooling medium and, the hardness is 77.75 HRc, 94.00 HRc and 112.73 HRc. When salt water (NaCl) is used as a cooling medium, the hardness is 45.6 HRc, 65.00 HRc and 88.50 HRc; while the media is oil cooling, the hardness is 32.25 HRc, 49.50 HRc and 75.24 HRc. When tempered at a temperature of 300oC, then dipped with H2O the hardness is 68.36 HRc, 80.11 HRc and 98.75 HRc. When dipped in NaCL the hardness is 40.60 HRc, 55.50 HRc and 79.90 HRc. Being cooled in the oil the hardness is 29.73 HRc, 43.36 HRc and 67.18 HRc. When tempered at 300°C there is a decrease in hardness of 8% to 20% as well as being tempered at 400°C. All this results in hardness decrease. Cooling with water can reach the hardness of 61.40 HRc, 75.13 HRc and 87.40 HRc and being cooled in NaCl the hardness becomes 41.60 HRc, 50.39 HRc, 68.60 HRc and with oil is 32.27 HRc, 45.36 HRc and 58.93 HRc. There is a decrease in hardness of 18% to 25%. Being tempered at 500°C, the hardness decreases, being cooled with water the hardness becomes 59.36 HRc, 65.22 HRc, 72.57 HRc. Being tempered with salt water the hardness is 55.60 HRc, 59.20 HRc, 63.90 HRc and being cooled with oil the hardness is 36.60 HRc, 40.36 HRc, 52.18 HRc. In case of price before and after tempering, a decrease in hardness is about 24%-30%. Annealing at a temperature of 800°C the hardness is 15.65 HRc.
Keywords: Hardening, Normalizing, Tempering, Annealing, Hardness, Microstructure.
[PDF Full Text]