Attractive Characteristics of High-Chromium Iron-Based Alloys for Nuclear Reactor Application

Abstract

High‐chromium iron‐based alloys have attractive characteristics compared to those of conventional ferritic steels which have been considered to be promising candidate alloys for the next generation machines in place of austenitic stainless steels. Their expected properties of good corrosion resistance, low thermal stress factor, high strength at elevated temperatures, and in some cases low ferromagnetism are very desirable for advanced nuclear reactor application.

Recent Progress and Future R & D for High-Chromium Iron-Base and Chromium-Base Alloys

“…The values for Fe-50 mass% Cr alloy and pure chromium are about 0.10 and 0.04 MPa m/W, respectively. They are much smaller than those of ferritic and austenitic steels widely used as structural materials [14].…”

“…Owing to the high decay rate of neutron-induced radioactivity of chromium [17,18], chromium alloys have been considered as in-reactor components for fission and fusion application because of their good mechanical and physical properties as structural material [14,19]. The low activation criteria require a limit to the shortand long-term radioactivity of the alloys, taking into account their activity level, dose rate and specific decay heat.…”

“…[4]) 773 K and below, while in ferritic steels there is no clear yield drop; work-hardening is very small and cannot be observed above 573 K.The dependence of chromium content on the yield stress of Fe-Cr alloys is summarized inFig. 3, based on recent data[2,6,8,10,14]. The trend that the yield stress increases with increasing chromium content can be seen clearly.…”

Influence of atomic ordering on sigma phase precipitation of the Fe50Cr50 alloy

“…The Fe-Cr binary system exhibits special interest in the materials industry mainly due its high corrosion resistance as well as its mechanical strength [1,2]. The majority of the studies related to this system are performed near to the equiatomic region since in this region the r-FeCr phase is precipitated which deteriorates the mechanical properties of the alloy [3].…”

Study of Alpha-Sigma Phase Transformation in Mechanically Alloyed Fe-Cr-Sn Alloys

“…The latter phenomena include for instance spin and charge density waves and spin glasses on the chromium rich-side, a miscibility gap at low temperature in the central part of the equilibrium phase diagram which allows investigating phase separation by nucleation and growth or by spinodal decomposition, the formation of a sigma phase at high temperature, between about 800 and 1100 K, in near equiatomic alloys as also found in many transition-metal binary systems and resistance to corrosion. Among the numerous applications of Fe-Cr based alloys, we notice for instance their use in advanced nuclear reactor applications [1], due to their corrosion and heat resistance and relatively low cost. However, their properties deteriorate with sigma phase precipitation.…”