Microstructure evolution in bulk and surface states of chromium rich nickel based cast alloys reinforced by hafnium carbides after exposure to high temperature air

The domestic and overseas research progresses of microstructure of the concrete and fatigue damage after treated by high temperature are reviewed. The main research direction and current shortage on the high temperature process, fatigue damage and the microstructure evolution mechanism of concrete are discussed. A view of the application prospects of concrete research on the high temperature process, fatigue damage and the microstructure evolution mechanism of concrete is forecast.

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Research on Temperature Changes and Microstructure Evolution of Steel Target after the Penetration by Copper Jet

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.311-313.953 ◽

2011 ◽

Vol 311-313 ◽

pp. 953-956

Author(s):

Hao Chen ◽

Gang Tao

Keyword(s):

Grain Size ◽

High Temperature ◽

Temperature Distribution ◽

Microstructure Evolution ◽

Deformation Zone ◽

Superplastic Deformation ◽

Theoretical Formula ◽

Temperature Changes ◽

Normal Deformation ◽

Steel Target

In order to study dynamic response of metal, this paper makes use of theoretical formula to investigate changes of temperature and grain size on steel target after the penetration of copper jet based on data gathered from the experiments. Deformed target penetrated by copper jet could be divided into superplastic deformation zone and normal deformation zone according to the different microstructure. Temperature distribution of each deformation zones is in turn calculated by two constitutive equations. The results indicate that areas with high temperature concentrate on the narrow zone near the penetrated channel. Then, the calculation of grain size conforms to the observation. It is obviously proven that the method used in this paper is trustworthy for calculating the changes of temperature and grain size of target caused by penetration.

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Influence of High Temperature Annealing on Microstructure Evolution of Ni-24Fe-14Cr-8Mo Superalloy

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.904.117 ◽

2021 ◽

Vol 904 ◽

pp. 117-123

Author(s):

Yi Cui ◽

Yun Fei Zhang ◽

Yan Guang Han ◽

Da Lv

Keyword(s):

High Temperature ◽

Microstructure Evolution ◽

Testing Machine ◽

Aging Treatment ◽

Growth Patterns ◽

High Temperature Annealing ◽

Rockwell Hardness ◽

Hardness Testing ◽

X Ray Diffraction ◽

X Ray

The effect of high temperature annealing on microstructure evolution of Ni-24Fe-14Cr-8Mo alloy was investigated through Optical Microscopy (OM), Scanning Electron Microscopy (SEM), X-Ray Diffraction (XRD) and Rockwell Hardness Testing Machine. Three kinds of grain growth patterns were found at different annealing temperatures due to carbides precipitation and dissolution. After a combination of high temperature annealing and aging treatment, the hardness versus time curves performed a parabolic pattern. The highest hardness was achieved under 1070°C/60 minutes treatment, and the desirable annealing time should be 60 minutes to 90 minutes.

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