低炭素鋼に対するウランの添加 : 鉄鋼におよぼす U の影響に関する研究 I

概要

論文の詳細を見る
The depleted uranium as a by-product of the enriched uranium manufacturing has been accumulated enormously in these several years, since it is unfit for nuclear uses. For the purpose of utilization of depleted uranium for non-nuclear uses, a large number of studies concerning the effect of uranium addition on iron and steel have been made in the United States and Canada. Here, in Japan, in 1961, "The Special Committee for the Study of Uranium Steels", has been organized in "The Japan Society for the Promotion of Science" so that industrial and research fields may share studies systematically from the basic researches to the practical applications. In this paper, a laboratory study to reveal the principal effects of uranium addition to steel as an alloying element has been carried out. The aluminum-killed low carbon steels (<0.25%C) are chosen as the object of study on addition of small amount of uranium (<0.7%U). The results are as follows : (1) Recoveries of uranium from steels are 40 to 65% and related, in general, with the carbon contents as shown in Fig.1. (2) Non-metallic inclusions like sulfides and silicates decreased morphologically with uranium addition, but oxide inclusions increased remarkably. (3) Uranium refined the austenitic grain size of steels slightly. (4) As-normalized hardness suffered a little effect of uranium addition at a 0.06%C level but above a 0.16%C level the effect increased with the content of uranium. (5) After water-quenching from a solution temperature ranging 950℃ to 1250℃ in 0.06%C steels, secondary hardening occurred under the tempering up to 600℃. Microscopic examination showed that uranium caused pseudo-martensitic structure, and it also suggested that uranium had a solubility to austenite matrix to some extent. (6) After water-quenching from a ferrite region ranging 750 to 800℃, no ageing occurred at room temperature and at 150℃. It was suggested that uranium had not the slightest solubility to ferrite matrix. (7) It appeared from the end-quench tests that the hardenability of steel did not rise with uranium addition from a quenching temperature of up to 900℃, but above 950℃, uranium raised the hardenability of steels. So in low carbon steels, uranium formed the intermetallic compound Fe_2U. And it is considered that Fe_2U decomposed above 950℃, uranium had a solubility to austenite and had its hardenability improved, as mentioned above. (8) Mechanical properties at room temperature were not affected by uranium addition, but impact strength decreased with the content of uranium. (9) Transformation points of steels rose with uranium addition because of the stabilization of carbon from austenite matrix. (10) Uranium did not affect the work-hardening effect and since uranium fixed the interstitial atom like carbon and nitrogen, strain-ageing did not occur in silicon-killed uranium steel. (11) Corrosion resistance against 5% hydrochloric acid improved with an addition of uranium as shown in Canada's report but in 5% sulfuric acid severe pitting occurred, and in 3% nitric acid no beneficial effect was observed.
社団法人日本鉄鋼協会の論文
1963-11-01

低炭素鋼に対するウランの添加 : 鉄鋼におよぼす U の影響に関する研究 I

スポンサーリンク

概要

著者

関連論文

スポンサーリンク