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Nara-shi, Japan

Uda K.,Daido Chemical Industry Co. | Azushima A.,Yokohama National University | Yanagida A.,Tokyo Denki University
Journal of Materials Processing Technology | Year: 2016

The use of lubricants is effective for decreasing the forming load in hot stamping of Al-coated 22MnB5 steel. It is desired that new lubricants for hot stamping are developed. In this study, first, the coefficients of friction were measured using commercial lubricants for hot forging with the hot flat drawing simulator. The coefficient of friction of a commercial lubricant that consisted of a hydrophilic polymer and a mineral salt was the lowest. Second, lubricants with added different solid lubricants were newly developed and their coefficients of friction were measured. The coefficient of friction of the lubricant with added swellable mica was the lowest. Third, the formability of Al-coated 22MnB5 steel using the newly developed lubricant was examined with the hot deep drawing test machine and its formability was superior. A new high-performance lubricant for hot stamping was developed. © 2015 Elsevier B.V. Source


Azushima A.,Yokohama National University | Uda K.,Daido Chemical Industry Co. | Maki J.,Nippon Steel & Sumitomo Metal Corporation | Nomura N.,Nippon Steel & Sumitomo Metal Corporation
Journal of Materials Processing Technology | Year: 2016

It is desired that the coefficient of friction is reduced in hot stamping of the aluminized 22MnB5 steels. It was reported that ZnO coated aluminized steel reduced the coefficient of friction and the amount of Al-Fe intermetallic compounds (IMC) adhered on the tool surface. In this paper, the frictional behavior of ZnO coated aluminized 22MnB5 steel when sliding against tool steel was investigated. The non-coated tool and the coated tools with TiN, TiAlN and DLC-Si were used. The experimental tests were carried out under dry condition using the hot flat drawing test machine. The coefficients of friction for the drawing distance were measured. After drawing, the Al-Fe IMC adhered on the tool surface was analyzed and the profile of tool surface was measured. For the non-coated tool, the amounts of adhered Al-Fe IMC of ZnO coated aluminized 22MnB5 steel were lower than that of aluminized 22MnB5 steel, and the coefficients of friction decreased, On the other hand, for the coated tools, the coefficient of friction became lower and the adhered aluminum became significantly thinner. © 2015 Elsevier B.V. Source


Azushima A.,Yokohama National University | Uda K.,Daido Chemical Industry Co. | Matsuda H.,Yokohama National University
Journal of Materials Processing Technology | Year: 2014

The hot stamping of aluminum-coated 22MnB5 has usually been conducted under dry condition, for which the forming load is high since the coefficient of friction is over 0.5. In order to decrease the forming load, the authors previously proposed the use of a lubricant to decrease so that the coefficient of friction from over 0.5 to 0.3. However, it is necessary to understand the heat transfer property in hot stamping under lubricated condition. The purpose of this paper is to examine the heat transfer property of aluminum-coated 22MnB5 in hot stamping under dry and lubricated conditions. In this study, the die and specimen temperatures were measured during compression and compression-sliding tests under dry and lubricated conditions using the hot flat drawing test simulator. In the compression test, the die and specimen temperatures measured under dry and lubricated conditions were the same. On the other hand, in the compression-sliding test up to a sliding distance of 70 mm, the die temperature under lubricated condition was lower than that under dry condition, and it was found that the heat transfer under lubricated condition is superior to that under dry condition. Consequently, there is a difference between the specimen temperatures under dry and lubricated conditions. However, from the results of the tensile test, there is no difference between the tensile strengths under dry and lubricated conditions. © 2014 Elsevier B.V. All rights reserved. Source


Iida M.,Nara Womens University | Kawakami S.,Nara Womens University | Syouno E.,Daido Chemical Industry Co. | Er H.,Ningxia University | Taguchi E.,Osaka University
Journal of Colloid and Interface Science | Year: 2011

Ionic liquids of an N-alkylethylenediamine-silver(I) complex cation (alkyl=hexyl, 2-ethylhexyl, and octyl) or a protic N-alkylethylenediaminium cation (alkyl=butyl, hexyl, 2-ethylhexyl, octyl, decyl, and dodecyl) with a bis(trifluoromethanesulfonyl)amide counter anion (Ag-ILs and PILs, respectively) were prepared and their physicochemical properties were investigated. The trend of solidification decreased in the order octyl≫hexyl>2-ethylhexyl for the Ag-ILs, and butyl>dodecyl>decyl>octyl>hexyl≫2-ethylhexyl for the PILs. The diffusion coefficients of the cations indicated stronger intermolecular interactions in PILs than in the Ag-ILs because of hydrogen-bonding networks, and it has been revealed that the intermolecular interactions increase in the order, hexyl Source


Watanabe M.,Nara Womens University | Takemura S.,Nara Womens University | Kawakami S.,Nara Womens University | Syouno E.,Daido Chemical Industry Co. | And 3 more authors.
Journal of Molecular Liquids | Year: 2013

Protonation sites of a chelating mono-protic ionic liquid (PIL) comprising N-hexylethylenediaminium (= HHexen+) depending on the counter anion were studied by 15N and 13C NMR spectroscopy and DFT calculation. In the case of the bis(trifluoromethanesulfonyl) amide (= TFSA -) PIL, the protonation occurred almost at the secondary amine, whereas the protonation occurred preferentially at the primary amine in the trifluoroacetate (= TFA-) PIL. The formation of a chelating copper(II) complex with the cationic unit of the PIL despite the electrostatic repulsion was revealed using the paramagnetic broadenings of the 13C NMR spectra of the PILs. © 2013 Elsevier B.V. Source

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