BIMBINGAN TEKNIS DESAIN DAPUR PEMANAS MODEL TERTUTUP DAN CEROBONG GANDA PADA MANAJEMEN BISNIS UKM PANDAI BESI WILAYAH DISPERINDAG KABUPATEN MALANG

Abstract

The trial of an open heating kitchen with a length of 1100 mm, a width of 900 mm, a height of 700 mm and walls made of refractory brick and red brick were able to produce a heat temperature of 9250 C compared to a closed heating kitchen which was only able to produce a hot temperature of 7200C. The results of the hardness test after the metal was hot forged and continued with the oil cooling process, the highest hardness number for cooling SAE 40 oil was 88 HRB and the lowest hardness number for cooling SAE 140 oil was 85 HRB. The hardness number decreases due to the viscosity of the oil getting thicker, as a result the cooling rate is slower and the grain size is getting coarser, so that the metal is easily hot forged. Observation of the microstructure on the metal surface as a result of hot forging oil cooling with 200 x magnification is generally more dominant in the ferrite phase than the pearlite phase and the cross section of the metal as a result of hot forging oil cooling with 200 x magnification, in general low carbon steel and high carbon steel have been merges. The ferrite phase is ductile, has low hardness and the pearlite phase is hard but brittle. On cooling the oil, the martensite phase is not formed which is very hard and brittle, this is because during the cooling process all types of austenite phase oil cannot be transformed into the martensite phase.