Fu Hanguang

Structures and Properties of High-Carbon High Speed Steel by RE-Mg-Ti Compound Modification

The effects of rare earths (RE)-Mg-Ti compound modification on the structures and properties of high-carbon high speed steel (HSS) were researched. The impact toughness (αk), the fracture toughness (K1c) and threshold of fatigue crack growth (ΔKth) are tested. The thermal fatigue test is done on a self-straining thermal fatigue tester, the wear test is done on a high temperature wear test machine. The results show that the matrix can be refined by the RE-Mg-Ti compound modification, the eutectic carbides are inclined to spheroidicize and are distributed evenly, the morphology and distribution of eutectic carbides are unproved by appropriate RE-Mg-Ti complex modification. After RE-Mg-Ti compound modification, a little effects can be found on the strength, hardness and red hardness, but the fracture toughness (K1c) and threshold of fatigue crack growth (ΔKth) are improved in the meantime, the impact toughness (αk) is increased by over one time, and the resistance to thermal fatigue and wear resistance at an elevated temperature are remarkably improved.The effects of rare earths (RE)-Mg-Ti compound modification on the structures and properties of high-carbon high speed steel (HSS) were researched. The impact toughness (αk), the fracture toughness (K1c) and threshold of fatigue crack growth (ΔKth) are tested. The thermal fatigue test is done on a self-straining thermal fatigue tester, the wear test is done on a high temperature wear test machine. The results show that the matrix can be refined by the RE-Mg-Ti compound modification, the eutectic carbides are inclined to spheroidicize and are distributed evenly, the morphology and distribution of eutectic carbides are unproved by appropriate RE-Mg-Ti complex modification. After RE-Mg-Ti compound modification, a little effects can be found on the strength, hardness and red hardness, but the fracture toughness (K1c) and threshold of fatigue crack growth (ΔKth) are improved in the meantime, the impact toughness (αk) is increased by over one time, and the resistance to thermal fatigue and wear resistance at an elevated temperature are remarkably improved.