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| Study on Thermal Physical Properties of 304 Stainless Steel at High Temperature |
| DONG Fang,QIE Jun-mao,DENG Hao-hua |
| College of Metallurgy and Material Science and Engineering， Inner Mongolia University of Science and Technology， Baotou 014010， Nei Mongol， China |
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Abstract The DIL402C thermal dilatometer and STA449C thermal analyzer were employed to test the linear expansion and contraction coefficient，specific heat cp and DSC curve of 304 stainless steel. The result shows that the range of linear expansion coefficient was 20.9700×10-6～21.5712×10-6K-1 during heating and the range of linear contraction coefficient was 21.2528×10-6～21.9471×10-6K-1 during cooling. The linear expansion and contraction coefficient were higher than other materials，so the 304 stainless steel belong to the crack sensitive steel. The curve of cp oscillates obviously during the 900~1400℃ as temperature raise. Because of the transformation of crystalline shape occurs, the defects of casting blank occur easily. A endothermic peak exists obviously at 1420.8℃ during the DSC test. The sample began to melt at 1420.8℃ and the peak temperature was 1438.86℃ in the heating step. The sample began to solidify at 1439℃ and the peak temperature was 1435.6℃ in the cooling step. During the 1439~1100℃ as temperature fell，the curve of DSC was unsmooth，the thermostability was bad and phase change occurs. These factors cause the initial solidified shell non-homogeneous. These temperature points belong to the upper of crystallizer，so the casting blank causes crackle easily during this temperature range.
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Received: 04 July 2013
Published: 16 May 2014
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2014, Vol. 24 
