Calculation of the residual stress of a 45 steel cylinder with a non-linear surface heat-transfer coefficient including phase transformation during quenching

Using finite element method, a quenching analysis of 7075 aluminum alloy thick plate is carried out. The effect of surface heat transfer coefficient and plate thickness on residual stress, and the effect of cladding material on residual stress are discussed. It shows that the bigger surface heat transfer coefficient or thickness is, the bigger the residual stress is, and the residual stress significantly reduces while the cladding material exists. Experiments validated the simulation results.

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Study on Surface Heat Transfer Coefficient of Mixture of Nitrogen-Spray Water Eject Quenching under Normal Pressure and High Velocity

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.55-57.1142 ◽

2011 ◽

Vol 55-57 ◽

pp. 1142-1147

Author(s):

Bao Dong Shao ◽

He Ming Cheng ◽

Jian Yun Li ◽

Zi Liang Li ◽

Li Jun Hou ◽

...

Keyword(s):

Heat Transfer ◽

Phase Transformation ◽

Heat Transfer Coefficient ◽

Transfer Coefficient ◽

High Velocity ◽

Normal Pressure ◽

Martensite Phase ◽

Surface Heat ◽

Surface Heat Transfer ◽

Surface Heat Transfer Coefficient

During mixture of Nitrogen and spray water ejecting quenching under normal pressure and high velocity, the liquid film that is formed on the surface of specimen to reduce the heat transfer between specimen and quenching media is removed on the one hand; on the other hand, the heat transfer performance of the mixture exceeds that of pure Nitrogen. Because the surface heat transfer coefficient is difficult to measure, according the cooling curve of surface and centre of specimen measured experimentally, the law of surface heat transfer coefficient and specimen temperature is calculated by nonlinear estimate methods and finite difference method based on inverse heat transfer method. The results show that the cooling performance of mixture of Nitrogen and spray water is as well as that of water or oil. During quenching, the surface heat transfer coefficient increases rapidly at begin, and at temperature of 170 °C, the surface heat transfer coefficient decreases. During martensite phase transformation, the latent heat is used to increase drive force of phase transformation and to overcome resistance of phase transformation, thus the martensite phase transformation can fulfill.

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Calculation of thermal stress field with non-linear surface heat-transfer coefficient during quenching

Metals and Materials ◽

10.1007/bf03026365 ◽

1998 ◽

Vol 4 (4) ◽

pp. 601-604 ◽

Cited By ~ 3

Author(s):

Heming Cheng ◽

Honggang Wang ◽

Xieqing Huang

Keyword(s):

Heat Transfer ◽

Heat Transfer Coefficient ◽

Thermal Stress ◽

Stress Field ◽

Transfer Coefficient ◽

Surface Heat ◽

Surface Heat Transfer ◽

Thermal Stress Field ◽

Non Linear ◽

Surface Heat Transfer Coefficient

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The Research on the Key Factor Affect the Precision in Stress Analysis for the Rotor of Steam Turbine

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.275-277.83 ◽

2013 ◽

Vol 275-277 ◽

pp. 83-86

Author(s):

Chun Lin Zhang ◽

Nian Su Hu ◽

Wen Yang ◽

Jian Mei Wang ◽

Min Li ◽

...

Keyword(s):

Heat Transfer ◽

Heat Transfer Coefficient ◽

Numerical Calculation ◽

Transfer Coefficient ◽

Stress Analysis ◽

Surface Heat ◽

Flow State ◽

Surface Heat Transfer ◽

Surface Heat Transfer Coefficient ◽

Key Factor

With the development of the power grid, the proportion of large capacity unit is increasing rapidly. It requires a more in-depth study on the reliability of the unit, especially for the unit adjusting the peak. This paper concerned on the research of the surface heat transfer coefficient, which is the key factor affect the precision in thermal stress analysis. The surface heat transfer coefficient is obtained via the numerical calculation for the steam’s flow state and the transient heat transfer between rotor. This paper mainly describes the steam’s flow state and the transient heat transfer with the steam seal, and the results show that the direct numerical calculation is resultful in this subject.

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