TENSILE PROPERTIES OF PRE-HEATED BITUMEN QUENCHED DUAL PHASE MEDIUM CARBON STEEL
Abstract
The tensile properties of Dual Phase Steel (DPS) duplex structure-produced by quenching in pre-heated bitumen have been investigated. Medium carbon steels intercritically heated at different temperatures and holding times were quenched in hot bitumen pre-heated to 2800C. Optical and scanning electron microscopy characterisation of the duplex structure revealed extensive network of fibrous martensite in a ferritic matrix with occasional presence of polygonal martensite. The duplex phase structure exhibited continuous yielding dynamics improving the tensile, hardness and elongation by 42, 35 and 45% respectively relative to the values obtained in the normalised sample. But, the elongation of the sample heat treated at 8100C for 60 minutes decreased by 18% when compared to the elongation in the normalised sample. The values obtained are comparable to previously reported investigation in duplex structure produced using conventional oil quenching. This work suggests that pre-heated bitumen can be exploited for the production of DPSs.
