Hardening of Iron St 37 with Various heat Treatments Using Cooling Crude Palm Oil (CPO)

Abstract: Hardening of iron st 37 is a process carried out to improve the mechanical properties of the strength of the material it has. With good strength,
it can withstand the compressive loads received by the material. The hardening process carried out to improve the mechanical properties of the ST 37
material is by the Quencing method using Crude Palm Oil (CPO), where the ST 37 material is heated from a temperature of 200 ᵒC, 400ᵒC, 600ᵒC,
800ᵒC and 965ᵒC and immediately cooled them. The hardening process carried out with each experiment uses 5 pcs of workpieces and after the
quencing process is done, the testing process presses on the workpiece. The results obtained from the hardening of the ST 37 workpiece, resulted in
several parameters of the increase in the value of the hardness that occurred from the specimens that had been heated and quenching CPO in the
200ᵒC heating specimen was 24.4% (49 HRC) against the untreated specimens (37 HRC), increase in the hardning of specimens carried out by heating
400ᵒC, 600ᵒC, 800ᵒC, 965ᵒC is as much as 36.6% (59 HRC), 31.9% (55 HRC), 9.7% (41 HRC) and 29.9% (53 HRC). So the most superior hardness
value is in specimens that use 400ᵒC heating by quenching CPO.