Effect of Second-Stage-Aging on the Fatigue Properties of Maraging Steel
Maraging steels are known to have not only ultrahigh strength but also large toughness so that they are promised to be as used as components or parts with structural integrity.It is also known that maraging steels are conventionally aged in two steps to obtain such good mechanical properties.Some of the present authors showed that one-step-aged maraging steels exhibited the increase in fatigue strength at intermediately high temperatures of 473 K and 673 K,compared with the strength obtained at room temperature.In addition,when low-temperature aging at 473 K and 673 K was given to one-step-aged maraging steels by varying the aging time,this second-step-aging increased the hardness of the steel.It also increased fatigue strength in an environmental situation where high humidity markedly reduced the fatigue life of one-step-aged steels.These results strongly suggest that the second-step-aging at low temperatures produces some additional microstructures which impede plastic deformation and increases resistance to fatigue cracking,even in the environmental conditions which accelerate the deformation and fracture.In the present report,a microstructural model will be proposed to interpret the effect of second-step-aging on the mechanical properties of maraging steel,which will explain the improvement of fatigue strength at intermediately high temperature and in high humidity condition.
Maraging steel Fatigue Two-step-aging Microstructure Environmental effect
Norio Kawagoishi Kohji Kariya Takanori Nagano Yuzo Nakamura
Department of Mechanical System Engineering,Daiichi Institute of Technology Kirishima 899-4395,Japan Department of Mechanical Engineering,Miyakonojo National College of Technology Miyakonojo 885-8567,J Department of Mechanical Engineering,Graduate School of Science and Engineering Kagoshima University
国际会议
北京
英文
1-10
2013-06-16（万方平台首次上网日期，不代表论文的发表时间）