High temperature mechanical strength and microstructural stability of advanced 9-12%Cr steels and ODS steels.
The present study proposes a comparison between several martensitic and ferritic steels in terms of creep strength and cyclic softening effect. The damage mechanisms are identified using fractographic observations and the microstructural evolutions are observed by TEM. The effects of a modified chemical composition on the high temperature mechanical behaviour are studied.
High-temperature low-cycle fatigue behavior of novel austenitic ODS steels
Abstract The focus of this study is to investigate the low-cycle fatigue (LCF) behavior of two newly developed austenitic 17Cr13Ni–W ODS steels. The LCF tests were performed at 650 °C with strain amplitudes ranging from 0.4 to 0.9%. The cyclic stress response and the cyclic strain-life resistance were analyzed in detail and compared with two non-ODS austenitic stainless steels (304 and 316L(N)) and a ferritic-martensitic ODS steel based on T91. The austenitic ODS steels showed stabilized cyclic response after a slight initial cyclic hardening. Due to their high strength at elevated temperatures, the strain-life resistance became superior with decreasing total strain amplitude compared to the other materials considered.
A Hopewellian Burial Site in the Lower Republican Valley, Kansas
The senior author has for a number of years worked on the problem of the numerous and virtually unknown burial sites on the bluffs bordering the valley of the Republican River in Geary and Clay Counties, Kansas. This work has been a matter of some urgency, owing to the prevalence of unsystematic amateur excavation on the more prominent stone cairns found in the area. Fortunately, the complete excavation of the larger cairns involves too much labor for the merely curious, and it has often been possible to salvage material and information despite disturbance.