Deformation and Fracture Characteristics of Titanium Alloys at Low Temperatures
Kotobu NAGAI, Keisuke ISHIKAWA
pp. 707-715
Grid List Abstracts
ONLINE ISSN: | 1883-2954 |
PRINT ISSN: | 0021-1575 |
Publisher: | The Iron and Steel Institute of Japan |
Backnumber
Vol. 110 (2024)
Vol. 109 (2023)
Vol. 108 (2022)
Vol. 107 (2021)
Vol. 106 (2020)
Vol. 105 (2019)
Vol. 104 (2018)
Vol. 103 (2017)
Vol. 102 (2016)
Vol. 101 (2015)
Vol. 100 (2014)
Vol. 99 (2013)
Vol. 98 (2012)
Vol. 97 (2011)
Vol. 96 (2010)
Vol. 95 (2009)
Vol. 94 (2008)
Vol. 93 (2007)
Vol. 92 (2006)
Vol. 91 (2005)
Vol. 90 (2004)
Vol. 89 (2003)
Vol. 88 (2002)
Vol. 87 (2001)
Vol. 86 (2000)
Vol. 85 (1999)
Vol. 84 (1998)
Vol. 83 (1997)
Vol. 82 (1996)
Vol. 81 (1995)
Vol. 80 (1994)
Vol. 79 (1993)
Vol. 78 (1992)
Vol. 77 (1991)
Vol. 76 (1990)
Vol. 75 (1989)
Vol. 74 (1988)
Vol. 73 (1987)
Vol. 72 (1986)
Vol. 71 (1985)
Vol. 70 (1984)
Vol. 69 (1983)
Vol. 68 (1982)
Vol. 67 (1981)
Vol. 66 (1980)
Vol. 65 (1979)
Vol. 64 (1978)
Vol. 63 (1977)
Vol. 62 (1976)
Vol. 61 (1975)
Vol. 60 (1974)
Vol. 59 (1973)
Vol. 58 (1972)
Vol. 57 (1971)
Vol. 56 (1970)
Vol. 55 (1969)
Vol. 54 (1968)
Vol. 53 (1967)
Vol. 52 (1966)
Vol. 51 (1965)
Vol. 50 (1964)
Vol. 49 (1963)
Vol. 48 (1962)
Vol. 47 (1961)
Vol. 46 (1960)
Vol. 45 (1959)
Vol. 44 (1958)
Vol. 43 (1957)
Vol. 42 (1956)
Vol. 41 (1955)
09 Nov. (Last 30 Days)
Kotobu NAGAI, Keisuke ISHIKAWA
pp. 707-715
Masaaki ISHIO
pp. 716-722
Noboru SATO
pp. 723-731
Takashi IKEDA, Masafumi MAEDA
pp. 742-749
Abstract
A Thermogravimetric technique was used to achieve accurate measurements of carbon dioxide dissolution in molten CaO-CaCl2-CaF2 fluxes. The effects of temperature as well as composition of flux on carbon dioxide dissolution are studied.
Experiments were conducted at a temperature range from 900 to 1500°C. The solubility in fluxes of XCaOinit. = 0.12 increased from 0.44 to 0.97wt% as replacing CaCl2 by CaF2 at 1100°C and it decreased from 2.95wt% to 0.21wt% with increasing temperature at constant XCaF2init. of 0.6. Results obtained in this study were compared with those appearing in the literature. Carbonate capacities calculated from the solubility data at 1500°C were compared with sulphide capacities, phosphate capacities, phosphide capacities, nitride capacities and cyanide capacities in CaO-CaF2 system. Linear relations were observed between carbonate capacities and other capacities on log-log plots.
Minoru SASABE, Shunji TAKASHIMA, Hiroyuki HIRASAWA
pp. 750-757
Abstract
If reaction products of steelmaking reaction are gaseous, some problems on produced slags are reduced. Present work examined fundamentally, if desiliconization by vaporization method was possible or not.
About 30g of molten iron saturated by carbon and containing various amounts of silicon was melted in a graphite crucible. When Cl2 is blown into the molten iron, chlorination of silicon and ferrous metal occurred simultaneously. Since chlorination rate of ferrous metal is faster than that of silicon, silicon is enriched in the molten iron apparently. When FeCl2 powder filled in a pocket of plunger made of graphite is dipped into the molten iron, only silicon is chlorized.
The chlorination rate of silicon by FeCl2 can be expressed as a first order reaction equation with respect to silicon content in iron. The apparent rate constants of the reaction are affected by the plunger pocket size and mass of molten iron. However, the rate constants are not affected by temperature.
The relationship among initial silicon content of the molten iron, [%Si]O, that at time t [%Si]t, mass of FeCl2 in the plunger pocket, Wp, sum of mass of FeCl2 supplied to the molten iron, Wf, and mass of the molten iron, Ws, can be expressed as follows :
-In [%Si]t/[%Si]O= exp( -Wp-1.05)/ Ws0.81 Wf
The major reaction product was observed as SiCl4.
Kiyoshi TAKAGI, Tadashi NAITOU, Masamitsu OBASHI, Toshio INOUE, Hisashi HIRAISHI
pp. 758-765
Abstract
In a walking beam-type, furnace skid marks caused by skid buttons should be minimized, thus stabilizing slab quality and reheating performance. Not strong enough at high temperatures, the conventional cobaltbase resistance alloy develops compressive deformation after a short period of operation, entailig a gradual increase in skid marks.
In reconstructing the slab reheating furnace at the Mizushima hot strip mill from pusher-type with hot skids to walking beam-type, newly-developed 200 mm tall-profiled and 50 mm wide skid buttons of ceramic composite metal were put into service in March, 1986. These skid buttons contribute to improving slab quality by reducing skid marks, and minimizing troublesome deformation and other such damage.
Readers Who Read This Article Also Read
Tetsu-to-Hagané Vol.73(1987), No.2
Tetsu-to-Hagané Vol.76(1990), No.7
Tetsu-to-Hagané Vol.76(1990), No.5
Yoshio IKAWA, Tetsu ITAMI, Ken KUMAGAI, Tsuyoshi ANDO
pp. 766-773
Abstract
Rapid solidification process produces fine grains and macro-segrigation free microstructures and improves hot-workability of highly-alloyed metals (e.g. superalloys and high alloy steels).
The Osprey process is a spray deposition technique which is one of the rapid solidification methods.
This process provides a means of producing dense preforms directly from liquid metal by applying a gas atomizing. Therefore, this process retains most of advantages resulting from rapid solidification and powder metallurgy, while eliminates major disadvantages resulting from multi stage process (e.g. powder production, sizing, compaction and sintering).
In the present investigation, Osprey process has been applied to mill rolls satisfactorily.
Results obtained are as follows ;
1) Fine grain size was obtained by changing operational parameters.
2) Osprey preform with higher mechanical properties compared with conventional cast preform was obtained.
3) The wear amount of Osprey product is 1/2 to 1/6 of conventional cast one in wearing test.
4) Actually, the life of Osprey rolls tested in a wire-rod mill exceeded that of conventional ones by two to three times.
Readers Who Read This Article Also Read
Tetsu-to-Hagané Vol.73(1987), No.2
Tetsu-to-Hagané Vol.76(1990), No.7
Tetsu-to-Hagané Vol.76(1990), No.5
Ichiro TSUKATANI
pp. 774-781
Abstract
The effects of titanium, manganese and boron contents are studied on r-values and tensile properties of very low carbon sheet steel with extra deep drawability, for the purpose of producing cold-rolled sheet steel by a room-temperature coiling process after hot-rolling. The mean r-value (r) of the sheet produced by a process skipping coiling treatment after hot-rolling is better than that produced by a conventional coiling process at 700°C, if the soluble titanium/carbon atomic ratio is over 1.5 and the manganese content is less than 0.15%. This is probably due to the enhanced precipitation of Ti (C, N) during hot-rolling and cooling and the suppression of grain growth in hot-rolled sheets. The boron addition deteriorates the r-values of extra-low carbon titanium-killed sheet steels produced by both the conventional coiling and room-temperature coiling processes.
Takehide SENUMA, Hiroshi YADA, Ryou SHIMIZU
pp. 782-789
Abstract
From a viewpoint of deep drawability, the influence of chemical compositions on the texture formation of steel sheets hot rolled below Ar3 temperature (warm rolled) has been investigated using steels consisting of various combinations of carbon and titanium contents.
The formation of texture was greatly influenced by carbon in solution. A steel sheet warm rolled in the absence of carbon in solution revealed strong formation of near ND//<111> orientations in the recrystallization texture. On the other hand, ND//<111> orientations hardly developed and near{113}<110> was recognized as the main orientation of the recrystallization texture when carbon in solution were present.
Microscopic studies using transmission electron microscopy and selected area electron diffraction showed that, in the presence of carbon in solution, {114}<110> - {112}<110> orientations were formed in the vicinity of grain boundaries by some unique crystal rotation different from that occurring in the matrix.
The occurrence of the unique crystal rotation was explained by the variation of active slip systems caused by work hardening due to the interaction between dislocations and the interstitial atoms.
Besides, the influence of grain size before warm rolling and recrystallization temperature on the texture formation, both of which were affected by chemical compositions was also discussed.
Finally, proper chemical compositions for producing deep drawing steel sheets by warm rolling were suggested.
Kenichi USAMI, Toshinori OZAKI, Tsutomu ONUMA
pp. 790-797
Abstract
The roles of microstructures and alloying elements on cavitation·erosion resistanse of stainless steels are examined. The results are summarized as follows ;
1) Cavitation·erosion resistance of 13Cr martensitic stainless steel depends on metal hardness and has only little dependency to chemical composition. 2) The resistance of austenitic 18Cr-8Ni steels and similar steels depends on their chemical compositions and the erosion weight loss is determined by the hardness of the surface layer where strain induced martensitic transformation occurs due to the cavitation impact. 3) Cavitation·erosion resistance of austenitic high C-18Cr-6Co stainless steels is most excellent for wide range of Ni equivalent. This reason should be attributed especially to martensitic transformation characteristics related to alloying elements of Co and C.
Readers Who Read This Article Also Read
Tetsu-to-Hagané Vol.73(1987), No.2
Tetsu-to-Hagané Vol.76(1990), No.7
Tetsu-to-Hagané Vol.76(1990), No.5
Junichi SHIMOMURA, Yoshifumi NAKANO, Syozaburo NAKANO, Syuzo UEDA
pp. 798-805
Abstract
The effect of V on the disbonding between 2 1/4Cr-1Mo steels and austenitic stainless steel overlay was studied metallurgically. The addition of V into the base metal increases resistance to disbonding significantly. STEM and EDX observation showed that the fine precipitates are different in morphology, distribution and composition between V-modified and ordinary steels. The analyses of hydrogen diffusion and hydrogen evolution indicated that the fine precipiates in V-modified steel trap hydrogen and as a result increase the solubility of hydrogen and decrease the diffusion of hydrogen. Theoretical calculation of hydrogen distribution during cooling from high temperature and high pressure conditions showed that both diffusion and solubility of hydrogen in the base metal affects the concentration of hydrogen at the interface between base metal and stainless steel overlay. It is concluded that the fine precipitates in V-modified steel increase resistance to disbonding by reducing the concentration of hydrogen at the interface during cooling.
Iwao SAWAI, Yoshio OKUNO, Ken SUZUKI, Toshihei MISAWA
pp. 806-811
Abstract
For the purpose of further increasing use with the adhesive bonding in steel structural joints, adhesion tensile strength tests were carried out on a S55C high carbon steel/epoxy resin adhesive system under 20°C. Effects of heating temperature and its holding time on tensile strength and adhesion process were discussed for evaluating optimum hardening conditions. Probability distribution of adhesion tensile strength was found to be followed by Weibull distribution. The temperature-time-adhesion tensile strength (TTS1) diagram described by the mean value strength and Weibull shape parameter was illustrated to give a clear feature on the whole adhesion strength. The adhesion tensile strength obtained for various heating temperatures and times was divided into three stages in Larson-Miller parameter plot, that is, incomplete adhesion stage I of cohesive failure, suitable adhesion stage II of cohesive failure and deterioration adhesion stage III of cohesive-interface mixing failure mode. Thus, it became possible to evaluate the optimum hardening condition for adhesion joint strength using TTS1 diagram and/or Larson-Miller parameter plot.
Iwao SAWAI, Yoshio OKUNO, Toshihei MISAWA
pp. 812-816
Abstract
Effect of hardening treatment and test temperature on adhesion T-peel strength was investigated in a S55C high carbon steel/epoxy resin adhesive system, and was discussed the relationship between the peel and tensile adhesion strength. The results obtained are as follows :
(1) Probability distribution of adhesion peel strength in both initiation and propagation for fracture was found to be followed by Weibull distribution.
(2) Peel strength obtained for various heating temperatures and its holding times, tested under 20°C, was divided into three stages in Larson-Miller parameter plot, that is, incomplete adhesion stage I of cohesive failure, suitable adhesion stage II of cohesive failure and deterioration adhesion stage III of interface failure.
(3) The test temperature dependence on peel strength having peaks was observed and the fracture mode was cohesive failure below 60°C corresponding to the temperature of a maximum strength, whereas peel fracture was occurred at interface above 60°C.
(4) There lay a positive linear correlation between peel and tensile adhesion strength.
Yutaka KOIZUMI, Isao TOMIZUKA, Hiroshi HARADA, Tatsuyuki MAETA, Shizuo NAKAZAWA, Michio YAMAZAKI
pp. 817-824
Abstract
A study was made on effects of conditions of heat treatment on tensile properties at 760°C for HIP-consolidated powder of a Ni-base superalloy with a designed γ'-phase content of 65%.
The heat treatment comprised two or three stages : solutionizing, (intermediate heat treatment), and aging.
Experimental Yield-Strength (YS) and Ultimate-Tensile-Strength (UTS) were classified into two levels, depending on the conditions of heat treatment. The classification matched well with the difference of size of γ'-phase. Gamma-prime phase was fine and experimental YS and UTS were high, when cooling after solutionizing was rapid, or when an intermediate heat treatment at comparatively high temperature was applied. The reverses were the case when the rate of the cooling or the temperature of the intermediate heat treatment was reversed.
Rupture elongation significantly varied depending on the conditions of heat treatment. The variation, however, was not accounted for by change of structure. Elongation was large when cooling after solutionizing was slow, while it was small when solutionizing was prolonged, when cooling after it was rapid, or when an intermediate treatment was applied.
The best performance was obtained when a specimen was solutionized for 1 h and air-cooled thereafter, followed by aging without intermediate treatment.
Takanori NAKAZAWA, Hideo ABO, Mitsuru TANINO, Hazime KOMATSU
pp. 825-832
Abstract
Creep rupture ductility becomes one of the important properties of austenitic stainless steels as structural materials for fast breeder reactors. Using high purity nickel-chromium austenitic steels, the effects of carbon, nitrogen, and phosphorus on creep rupture ductility were investigated. Creep rupture tests were conducted at 600°C and extensive microstructural works were performed. The results were as follows.
Rupture strength increases with carbon or nitrogen content. Although the rupture ductility decreases with carbon, change in ductility with nitrogen is small. The ductility loss with carbon is due to the grain boundary embrittlement by carbides. With nitrogen, there is no precipitation during creep. Addition of phosphorus to ultra low carbon and nitrogen steels increases their rupture strength and ductility. Fine precipitates of (Fe, Cr)2P are uniformly dispersed in the grains and coarse (Fe, Cr)2P also precipitates on the grain boundary during creep. Grain boundary migration occurs extensively and few wedge type cracks are observed in the P containing steels. It is concluded that, from the viewpoint of increasing creep rupture ductility, nitrogen is much more effective than carbon and phosphorus is also beneficial.
Norihiko NAKAI, Mitsuo OBATA
pp. 833-840
Abstract
The purpose of this paper is to develop a non-destructive method for evaluating cooling-rates (time for cooling from austenitizing temperature to 500°C (Ht)) from 0.4C-5Cr-Mo-V hot-work tool steel specimens after tempering procedure. For this, the authors tried to employ Barkhausen noise (BHN) signals which were induced during magnetization process. The BHN signals were measured on surfaces of specimens which were cooled with various Ht and were tempered to adjust hardness (H). The experimental results indicated that two BHN parameters, the total energy (Vp) and the maximum output (Vh) of BHN signals were strongly related with microstructure which changed depending on Ht. These relationships could be successfully summarized as experimental expressions, Ht = f (H, Vp) and Ht = f (H, Vh). These results made it clear that non-destructive evaluation of Ht could be achieved by using a hybrid method combining the BHN method with an ordinary hardness test. Then in this paper, the authors confirmed the possibility of estimation of charpy impact values (Ch) through the relationship between Ht, H and Ch.
Akio KUROMATSU
pp. 841-847
09 Nov. (Last 30 Days)
ISIJ International Advance Publication
ISIJ International Vol.64(2024), No.8
ISIJ International Advance Publication
ISIJ International Advance Publication
ISIJ International Vol.64(2024), No.12
ISIJ International Advance Publication
Tetsu-to-Hagané Advance Publication
ISIJ International Advance Publication
ISIJ International Advance Publication
Tetsu-to-Hagané Advance Publication
You can use this feature after you logged into the site.
Please click the button below.
Please enter the publication date
with Christian era
(4 digits).
Please enter your search criteria.