Assessment of long-term refractory properties of selected types of austenitic steels

The major factors affecting long-term refractory properties of non-stabilized CrNiMo steels of type AISI 316, or AISI 304 with variable carbon, nitrogen and molybdenum contents, and titanium-stabilized steels of AISI 321 type are evaluated. These materials belong to the most widespread types of refractory steels used in pipes, sheets or forgings in nuclear power installations. The refractory properties of steels 17314, 17349, 17259 and 17360 were tested. It was shown that the hardening effect of nitrogen was more intense at its content of up to 0.1%. The carbon content did not have significant effect on the refractoriness of non-stabilized steels. The addition of molybdenum more than doubled the refractoriness of these steels as compared with titanium-stabilized steels. (J.B.). 2 tabs., 10 figs., 65 refs