| Hypoeutectic Fe-C-B alloy is a new kind of iron-based wear resistance material which the main alloying element is boron, in recent years, the alloy attracted more and more attentions due to its low cost of production, simple melting process and well castability. The non-chromium hypoeutectic Fe-0.4C-1.5B alloy was selected to study on the basis of predecessors’ research, Forging and rolling was used for deformation, the effect of deformation rate and quenching temperature after deformation on the hard phase morphology and distribution, mechanical properties and wear resistance of the alloy were researched, and combine with deformation and modification of rare earth in order to further improve the distribution of hard phase and the properties of the alloy were preliminary studied.The solidification microstructure of the Fe-0.4C-1.5B alloy is made up of pearlite, ferrite and eutectic ledeburite, the continuous network hard phase containing boron consists of Fe3(B,C) and Fe2B in ledeburite spilt the matrix which affect the performance of the alloy. The hard phase morphology is hard to be improved by heat treatment. The experiment results show that the hard phase continuous network morphology disappeared and broken into gathered particles after forging deformed. The continuous network hard phase was broken evidently while no gathered after rolling deformed. After deformed by forging and rolling, the continuity of matrix was enhanced and some second hard phase appeared, in addition, the hardness of the alloy increased a little and the impact toughness improved significantly.The study on the effect of rolling deformation rate indicated that in the range of0～66.7%deformation, with the increase of deformation rate, the broken of hard phase more and more evidently, the continuity of matrix gradually reinforced, ledeburite reduced and more gathered hard phase particles appeared, second hard phase increased. The hardness of the alloy no obvious changing rule, while the impact toughness increases and the wear resistance of the alloy rises. When deformation rate is66.7%, after austenitizing at1050℃for30min then quenched, the hardness of the alloy is58.3HRC, the impact toughness reached12.6J/cm2, and the wear resistance is1.21times as well as Cr20Mo high chromium cast iron.The research on quenching temperature for1.2forging rate deformed alloy shows that in the range of850℃～1100℃, with the increase of quenching temperature, the broken hard phases particles merged and formed bulk and strip hard phases appear, and the volume of hard phase decreased; The impact toughness decreased, while the hardness and wear resistance of the alloy were gradually increase to maximum and then decrease a little. When quenching temperature is1050℃, The hardness of the alloy is57.8HRC, impact toughness is9.3J/cm2, the wear resistance is very close to Cr20Mo high chromium cast iron.The study on cerium modification indicated than with the increase of additive amount of rare earth, the clusters of ledeburite reduced, the hard phase coursing and continuous network local broke, the continuity of matrix strengthened, the hardness of the alloy no changing rule while the impact toughness decrease. The modification alloy after66.7%deformed and1050℃quenched, continuous network hard phase broken evidently and tend to be lengthened, a little second hard phase appeared. In addition, the hardness of the alloy increase slightly and the impact toughness increased1.67times on average, and with good wear resistance.Take into account of mechanical property and wear resistance, when added rare earth is0.2wt.%, deformation rate is66.7%and quenching temperature of deformed alloy is1050℃, best properties achieved. After that, the hardness of the alloy is58.9HRC, the impact toughness is14.3J/cm2, at the same time, the wear resistance of it is1.55times as well as Cr20Mo, which with good application prospect. |
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