Liuding WANG
,
Laizhu JIANG
,
Ming ZHU
,
Xiao LIU
,
Wangmin ZHOU
材料科学技术（英文）
The influence of double aging on the microstructure and mechanical properties of ultrahigh strength steel Aermet 100 was analyzed. Under the double aging, there is no apparent decrease in the strength of steel. However, the impact fatigue life can be prolonged by 35.5% and dynamic fracture toughness be raised by 22.6% respectively, as compared with the normal aging. Based on the observation of microscopic structure, the physical mechanism of the prolongation of impact fatigue life and the enhancement of stability of the reverted austenite, AR, is analyzed further. The results show that this new technique is a breakthrough of combination optimization between strength and toughness for Aermet 100 steel. In the light of the current understanding on this subject, the volume fracture of soften and tough AR formed in process of heat preservation at higher temperature of double aging increases drastically. Moreover, during the treatment of lower temperature of double aging, the carbon separating from the martensitic ferrite will diffuse into AR, resulting that the martensitic brittleness decreases and the stability of AR increases.
关键词:
Ultrahigh strength steel
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null
,
null
,
null
Liuding WANG
,
Junqiang ZHOU
,
Quanxi CAO
,
Zhao CHEN
材料科学技术（英文）
The intensity and position of sidebands (satellites) on both sides of main diffraction peak in a great number of X-ray diffraction profiles of alloys always change with progress of aging. The sidebands position is determined by a newly optimized Voigt function in present investigation. Furthermore, for Cu-4 wt pct Ti alloy aged at 400℃ for 720 min and 1080 min, after introducing the weight factor of above two satellites intensity, the relative error between the fitting curves and X-ray diffraction profiles is less than 0.185%, which is more precise than the previously calculating result.
关键词:
X-ray diffraction
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null
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null
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null
Liuding WANG
,
Changle CHEN
,
Yimin SHI
,
Mokuang KANG
,
Bangjie JI
材料科学技术（英文）
The α and β phases in Cu-Zn alloy system were regarded as regular solutions at elevated temperature, the results calculated from the experimental data have showed that the value of the interaction parameter of components Cu and Zn in the α phase ECuZnα varied obviously with decreasing component Zn. Substituting the function relation between ECuZnα and XZn obtained through curve-fitting into expression of free-energy variation of the system, the calculated martensitic transformation temperature Ms was in good agreement with experimental curve, so as to have more comprehensive information for fully making use of binary Cu-base functional materials.
关键词:
Liuding WANG
,
Changle CHEN
,
Mokuang KANG
材料科学技术（英文）
The depleted and enriched regions of solute atoms formed by spinodal decomposition in the early stage of tempering for ultrahigh strength steel 23Co14Ni12Cr3 were first confirmed by means of transmission electron microscopy (TEM). The segregation of solute atoms provides favorable composition and structure fluctuationfor the formation of secondary hardening phase M2C and cementite Fe3C.
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