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Study of the quenching and subsequent return to room temperature of uranium-chromium, uranium-iron, and uranium-molybdenum alloys containing only small amounts of the alloying element; Etude de la trempe et du revenu a la temperature ordinaire d'alliages uranium-chrome, uranium-fer et uranium-molybdene, a faible teneur en element d'alliage

Abstract

By means of an apparatus which makes possible thermal pre-treatments in vacuo, quenching carried out in a high purity argon atmosphere, and simultaneous recording of time temperature cooling and thermal contraction curves, the author has examined the transformations which occur in uranium-chromium, uranium-iron and uranium-molybdenum alloys during their quenching and subsequent return to room temperature. For uranium-chromium and uranium-iron alloys, the temperature at which the {gamma} {yields} {beta} transformation starts varies very little with the rate of cooling. For uranium-molybdenum alloys containing 2,8 atom per cent of Mo, this temperature is lowered by 120 deg. C for a cooling rate of 500 deg. C/mn. The temperature at which the {beta} {yields} {alpha} transformation starts is lowered by 170 deg. C for a cooling rate of 500 deg. C/mn in the case of uranium-chromium alloy containing 0,37 atom per cent of Cr. The temperature is little affected in the case of uranium-iron alloys. The addition of chromium or iron makes it possible to conserve the form {beta} at ordinary temperatures after quenching from the {beta} and {gamma} regions. The {beta} phase is particularly unstable and changes into needles of the {alpha} form even at room temperatures according to an autocatalytic transformation  More>>
Authors:
Delaplace, J [1] 
  1. Commissariat a l'Energie Atomique, Saclay (France). Centre d'Etudes Nucleaires
Publication Date:
Sep 15, 1960
Product Type:
Thesis/Dissertation
Report Number:
CEA-R-1399
Resource Relation:
Other Information: TH: These metallurgie et des mines; 25 refs
Subject:
36 MATERIALS SCIENCE; CHEMICAL REACTION KINETICS; CHROMIUM ADDITIONS; CRYSTAL-PHASE TRANSFORMATIONS; DILATANCY; INERT ATMOSPHERE; IRON ADDITIONS; MICROSTRUCTURE; MOLYBDENUM ALLOYS; PHASE DIAGRAMS; PHASE STUDIES; QUENCHING; SHRINKAGE; TEMPERATURE DEPENDENCE; TEMPERING; TIME DEPENDENCE; URANIUM BASE ALLOYS; URANIUM-ALPHA; URANIUM-BETA; URANIUM-GAMMA; VACUUM FURNACES
OSTI ID:
20942992
Research Organizations:
CEA Saclay, 91 - Gif-sur-Yvette (France); Faculte des Sciences de Nancy, 54 (France)
Country of Origin:
France
Language:
French
Other Identifying Numbers:
TRN: FR07R1399096445
Availability:
Available from INIS in electronic form
Submitting Site:
FRN
Size:
56 pages
Announcement Date:
Dec 13, 2007

Citation Formats

Delaplace, J. Study of the quenching and subsequent return to room temperature of uranium-chromium, uranium-iron, and uranium-molybdenum alloys containing only small amounts of the alloying element; Etude de la trempe et du revenu a la temperature ordinaire d'alliages uranium-chrome, uranium-fer et uranium-molybdene, a faible teneur en element d'alliage. France: N. p., 1960. Web.
Delaplace, J. Study of the quenching and subsequent return to room temperature of uranium-chromium, uranium-iron, and uranium-molybdenum alloys containing only small amounts of the alloying element; Etude de la trempe et du revenu a la temperature ordinaire d'alliages uranium-chrome, uranium-fer et uranium-molybdene, a faible teneur en element d'alliage. France.
Delaplace, J. 1960. "Study of the quenching and subsequent return to room temperature of uranium-chromium, uranium-iron, and uranium-molybdenum alloys containing only small amounts of the alloying element; Etude de la trempe et du revenu a la temperature ordinaire d'alliages uranium-chrome, uranium-fer et uranium-molybdene, a faible teneur en element d'alliage." France.
@misc{etde_20942992,
title = {Study of the quenching and subsequent return to room temperature of uranium-chromium, uranium-iron, and uranium-molybdenum alloys containing only small amounts of the alloying element; Etude de la trempe et du revenu a la temperature ordinaire d'alliages uranium-chrome, uranium-fer et uranium-molybdene, a faible teneur en element d'alliage}
author = {Delaplace, J}
abstractNote = {By means of an apparatus which makes possible thermal pre-treatments in vacuo, quenching carried out in a high purity argon atmosphere, and simultaneous recording of time temperature cooling and thermal contraction curves, the author has examined the transformations which occur in uranium-chromium, uranium-iron and uranium-molybdenum alloys during their quenching and subsequent return to room temperature. For uranium-chromium and uranium-iron alloys, the temperature at which the {gamma} {yields} {beta} transformation starts varies very little with the rate of cooling. For uranium-molybdenum alloys containing 2,8 atom per cent of Mo, this temperature is lowered by 120 deg. C for a cooling rate of 500 deg. C/mn. The temperature at which the {beta} {yields} {alpha} transformation starts is lowered by 170 deg. C for a cooling rate of 500 deg. C/mn in the case of uranium-chromium alloy containing 0,37 atom per cent of Cr. The temperature is little affected in the case of uranium-iron alloys. The addition of chromium or iron makes it possible to conserve the form {beta} at ordinary temperatures after quenching from the {beta} and {gamma} regions. The {beta} phase is particularly unstable and changes into needles of the {alpha} form even at room temperatures according to an autocatalytic transformation law similar to the austenitic-martensitic transformation law in the case of iron. The {beta} phase obtained by quenching from the {beta} phase region is more stable than that obtained by quenching from the {gamma} region. Chromium is a more effective stabiliser of the {beta} phase than is iron. Unfortunately it causes serious surface cracking. The {beta} {yields} {alpha} transformation in uranium-chromium alloys has been followed at room temperature by means of micro-cinematography. The author has not observed the direct {gamma} {yields} {alpha} transformation in uranium-molybdenum alloys containing 2,8 per cent of molybdenum even for cooling rates of up to 2000 deg. C/s. He has however observed the formation of several martensitic structures. (author) [French] Grace a un appareillage qui permet d'effectuer les traitements thermiques prealables sous vide, de conduire la trempe dans une atmosphere d'argon tres pur et d'enregistrer a la fois les courbes de refroidissement temperature-temps et la courbe dilatometrique, l'auteur a etudie les transformations que subissent les alliages uranium-chrome, uranium-fer et uranium-molybdene pendant leur trempe et leur revenu ulterieur a la temperature ordinaire. Dans les alliages uranium-chrome et uranium-fer, la temperature de debut de la transformation {gamma} {yields} {beta} varie tres peu avec la vitesse de refroidissement. Dans les alliages uranium-molybdene a 2,8 at. Mo pour cent, elle est abaissee de 120 deg. C pour une vitesse de refroidissement de 500 deg. C/minute. La temperature de debut de la transformation {beta} {yields} {alpha} est abaissee de 170 deg. C pour une vitesse de refroidissement de 500 deg. C/minute dans l'alliage uranium-chrome a 0,37 at. Cr pour cent. Elle est assez peu modifiee dans le cas des alliages uranium-fer. L'addition de chrome ou de fer permet de retenir la forme {beta} a la temperature ordinaire par trempe depuis les domaines {beta} et {gamma}. Particulierement instable, la phase {beta} se transforme en aiguilles {alpha}, des la temperature ordinaire, suivant une loi de transformation autocatalytique analogue a la loi de transformation martensique de l'austenite dans le cas du chrome et a la loi de transformation bainitique de l'austenite dans le cas du fer. La phase {beta} obtenue par trempe depuis le domaine {beta} est plus stable que celle que l'on retient par trempe depuis le domaine {gamma}. Le chrome est un stabilisant de la phase {beta} plus efficace que le fer. Malheureusement il provoque une fissuration importante. La transformation {beta} {yields} {alpha} des alliages uranium-chrome a la temperature ordinaire a ete enregistree par microcinematographie. Dans les alliages uranium-molybdene, a 2,8 pour cent de molybdene, l'auteur n'a pas observe de transformation directe {gamma} {yields} {alpha} meme pour les vitesses de refroidissement elevees pouvant atteindre 2000 deg. C/s. Il a observe la formation de plusieurs structures martensitiques. (auteur)}
place = {France}
year = {1960}
month = {Sep}
}