| Abstract |
| It is proved that there exists an ordering reaction in alloy 600. The differential scanning calorimetric (DSC) tests were carried out for the alloy 600 and a Ni2Cr alloy from room temperature to 800℃ Both an exothermic and an endothermic reaction are interpreted in a aspect of order-disorder reaction in the Ni-Cr and the Ni-Fe binary system. The exothermic reaction was observed only in the water quenched specimens from above 600℃ and the cold worked specimens. However, the endothermic reactions were observed at 490-560℃ in all specimens. Especially, a convex endothermic reaction was observed at about 500-620℃ for specimens aged at 474℃ for 1,100 and 10,000 h. In addition, the activation energy for an exothermic reaction in a quenched specimen after a 1095℃-0.5 hr treatment was Q = 190 kJ/mol (~2 eV/atom), which suggests that this reaction is related to a substitutional diffusion process. |
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| Key Words |
| Differential scanning calorimetry, DSC, Alloy 600, Order-disorder reaction, Short range order, SRO, Ni2Cr |
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