著者
池田 義雅 高村 正人 箱山 智之 大竹 淑恵 熊谷 正芳 鈴木 裕士
出版者
一般社団法人 日本鉄鋼協会
雑誌
鉄と鋼 (ISSN:00211575)
巻号頁・発行日
pp.TETSU-2017-080, (Released:2018-02-05)
参考文献数
17
被引用文献数
8

Neutron engineering diffraction is a powerful technique which provides the information of the micro structure of steels in bulk-average, while X-ray diffraction or Electron backscatter diffraction can provide information only from the surface layer. However, such measurement using neutron diffraction is typically performed in a large facility such as a reactor and a synchrotron, while a compact neutron source has never been used for this purpose. Authors have recently developed a neutron diffractometer installed in Riken Accelerator driven compact Neutron Source (RANS) and succeeded in the measurement of texture evolution of a steel sheet. In this study, we made an attempt to measure the volume fraction of retained austenite by RANS. Background noise was carefully eliminated in order to detect as many diffraction peaks as possible with low flux neutrons. The volume fraction was estimated by Rietveld analysis. The accuracy of the measurement result was discussed by comparing with those obtained by a large neutron facility (J-PARC TAKUMI). The volume fraction obtained by RANS with reasonable measurement time, i.e. 30-300 min, showed only 1-2% discrepancies with those obtained in J-PARC. These comparisons suggest that neutron diffraction by RANS is capable of quantitative analysis of the volume fraction of crystal phases, showing the possibility of practical use of an in-house compact neutron source in the industry.
著者
久保田 俊輔 峯田 元治 安井 純一 中江 秀雄
出版者
一般社団法人 日本鉄鋼協会
雑誌
鉄と鋼 (ISSN:00211575)
巻号頁・発行日
vol.97, no.11, pp.566-571, 2011-11-01 (Released:2011-11-01)
参考文献数
19

The metallurgical macro- and micro-structure, and the residualstress of the Japanese matchlock gun, fabricated at the late Edo period, have been investigated with an optical microscope, an SEM, an EPMA and an X-ray residual stress meter for estimating the fabricating process and their materials. This gun was fabricated by Udonbari (in Japanese) process, which is similar to that of the Russell's method, tubes was created by the joining together opposite edges of a flat iron strip with an iron core bar. The joining line was wavy. Their residual stress was mainly compressive and the values were from 180 to 280 MPa in the longitudinal direction and from 240 to 380 MPa at the transverse direction.The gun was made of low carbon steel with equiaxed ferrite grains; their grain size was mainly 10 μm partly with 100 μm and exceptionally more than 1000 μm grains. Moreover, we find the special banded structure, consisted of fine ferrite grains bands and large ferrite grains bands.The firing part was fabricated by the joining of five parts for getting the L-shape hole. The female screw was made by forging; therefore the shape was tapered screw and the male screw was cut from a low grade steel bar, confirmed by their macro-structure.
著者
大塚 真司 多田 英司 西方 篤 藤田 栄 水流 徹
出版者
一般社団法人 日本鉄鋼協会
雑誌
鉄と鋼 (ISSN:00211575)
巻号頁・発行日
vol.103, no.1, pp.27-35, 2017 (Released:2016-12-31)
参考文献数
22
被引用文献数
4 13

In this study, hydrogen absorption behavior of steels on a vehicle during driving and parking in deicing-salt-spraying areas was investigated by using temperature-compensating hydrogen absorption monitoring system. During the driving of the vehicle in the areas, hydrogen permeation current of steel was increased due to picking up of salt water from the road when the road was wet. On the other hand, during the parking of the vehicle, the magnitude of the hydrogen permeation current were indicated that the hydrogen permeation current in the automobile driving environments is related to both driving states of a vehicle and environmental conditions such as temperature and relative humidity.
著者
飯田 賢一
出版者
一般社団法人 日本鉄鋼協会
雑誌
鉄と鋼 (ISSN:00211575)
巻号頁・発行日
vol.66, no.5, pp.573-577, 1980-04-01 (Released:2010-01-18)
参考文献数
17
著者
増村 拓朗 谷口 大河 浦中 祥平 平嶋 一誠 土山 聡宏 丸山 直紀 白幡 浩幸 植森 龍治
出版者
一般社団法人 日本鉄鋼協会
雑誌
鉄と鋼 (ISSN:00211575)
巻号頁・発行日
vol.106, no.11, pp.835-843, 2020 (Released:2020-10-31)
参考文献数
22
被引用文献数
1 7

Electrical resistivity of low-carbon martensitic steels was measured to estimate the carbon concentration in solid solution. Since electrical resistivity is influenced not only by solute carbon but also by substitutional elements, lattice defects and second phase, the effects of these factors need to be subtracted from total electrical resistivity, in order to obtain the accurate solute carbon concentration by this method. As a result, the effects of dislocations and grain boundaries were much smaller than that of solute elements, being only 1 - 2% of the measured electrical resistivity, in martensitic steel. On the other hand, substitutional elements and retained austenite were found to be significantly effective. By subtracting these effects from the measured value, the change in electrical resistivity due to solute carbon, Δρsol.C, could be formulated as a function of the carbon concentration in solid solution of martensite, Csol, as follows:Δρsol.C [mΩmm] = 0.25 × Csol [mass%]The estimated solute carbon concentration was confirmed to correspond to the directly measured value by atom probe tomography.
著者
郡司 好喜
出版者
一般社団法人 日本鉄鋼協会
雑誌
鉄と鋼 (ISSN:00211575)
巻号頁・発行日
vol.80, no.7, pp.N371-N385, 1994-07-01 (Released:2009-06-19)
参考文献数
29
被引用文献数
1 3
著者
高橋 学
出版者
一般社団法人 日本鉄鋼協会
雑誌
鉄と鋼 (ISSN:00211575)
巻号頁・発行日
vol.100, no.1, pp.82-93, 2014 (Released:2013-12-31)
参考文献数
74
被引用文献数
8 41

Development in sheet steels has progressed with a strong relation with automotive industry in Japan. To meet with the requirements from automotive industry, various types of sheet steels including high and ultra-high strength steel sheets have been developed. Progresses in three types of steel series will be discussed by checking the historical facts and technologies and their contributions. Introductions of interstitial free (IF) steel and continuous annealing system are the important events in mild steel developments for panels. Extensive work on finding the optimum mixtures of hard and soft phases to improve elongation of steels contributed to improve the crashworthiness of autobodies. Continuous annealing system also played an important role in producing these advanced high strength steels. Precipitation is used in characteristic ways which is to scavenge solute carbon and nitrogen and to prevent coarse cementite particle precipitation. It is also worth to point out that the strong collaborative activities particularly characteristic in Japan between steel manufacturers and auto companies have affected on the progress in advanced sheet steels.
著者
足立 吉隆 田口 茂樹 弘川 奨悟
出版者
一般社団法人 日本鉄鋼協会
雑誌
鉄と鋼 (ISSN:00211575)
巻号頁・発行日
vol.102, no.12, pp.722-729, 2016 (Released:2016-11-30)
参考文献数
9
被引用文献数
21

Deep learning by convolution neural network (CNN) was applied to recognize a microstructure of steels. Three typical CNN-models such as LeNet5, AlexNet, and GoogLeNet were examined their accuracy of recognition. In addition to a model, an effect of learning rate, dropout ratio, and mean image subtraction on recognition accuracy were also investigated. Through this study, the potency of deep learning for microstructural classification is demonstrated.
著者
Koji Sugie Akira Taniguchi
出版者
一般社団法人 日本鉄鋼協会
雑誌
ISIJ International (ISSN:09151559)
巻号頁・発行日
vol.51, no.3, pp.513-520, 2011-03-15 (Released:2011-03-18)
参考文献数
56
被引用文献数
4 11

The bioavailability and durability of Fe released from decarburization steelmaking slag was examined for two marine diatom species. The bioavailability of Fe released from the slag was compared with that from the reagent FeCl3·6H2O in the presence or absence of the synthetic chelator ethylenediaminetetraacetic acid, which affects Fe speciation in seawater. The duration of bioavailability was determined by the recovery of the growth rate on intermittent additions of macro-nutrients other than Fe. Abiotic reduction of bioavailable Fe from the slag in seawater was also investigated for 5 or 15 d. Thus, the bioavailability of Fe released from the slag was observed to be sufficiently high to promote the maximum growth rate; this was similar to that observed with the reagent inorganic Fe. This implies that the iron released from the slag is a dissolved ferric and/or ferrous ion/hydroxide species. In the culture media, to which the slag was added at the concentration of 20 mg L−1, the slag supplied bioavailable Fe to two diatoms for 50 d. The probable duration for which the slag was available as an Fe source was approximately 10 times longer than the reported duration in in situ iron fertilization experiments. These results indicate that continuous Fe fertilization can be achieved by a single addition of the slag, and hence, we can reduce the energy and cost of ocean fertilization and also create a resource of microalgae biofuels.
著者
弘川 奨悟 田口 茂樹 松下 康弘 足立 吉隆
出版者
一般社団法人 日本鉄鋼協会
雑誌
鉄と鋼 (ISSN:00211575)
巻号頁・発行日
pp.TETSU-2017-003, (Released:2017-04-26)
参考文献数
12
被引用文献数
1

Screening important microstructure factors dominantly controlling a stress-strain curve of a dual phase steel was studied by three kinds of sparse modelling approach; Sensitive analysis, data transformation & variable selection, and Bayesian inference. In addition, an effect of data noise on descriptor screening in sparse modelling was also investigated.
著者
山木 正義
出版者
一般社団法人 日本鉄鋼協会
雑誌
鉄と鋼 (ISSN:00211575)
巻号頁・発行日
vol.45, no.5, pp.528-542, 1959-05-01 (Released:2009-05-26)
参考文献数
91
被引用文献数
1
著者
酒井 久裕 落合 鍾一 上野 學
出版者
一般社団法人 日本鉄鋼協会
雑誌
鉄と鋼 (ISSN:00211575)
巻号頁・発行日
vol.75, no.4, pp.657-664, 1989-04-01 (Released:2009-06-19)
参考文献数
22
被引用文献数
2

The purpose of this work is to present results on the mechanical properties of SUJ 2 bearing steel improved by a cyclic heat treatment. The structure of thermally cycled steel consists of fine-grained ferrite particles of the size under about 2 μm containing fine cementite particles of the size about 0.2μm. Thermally cycled steel was found to be superplastic at 710°C, just below A1 temperature, at an initial strain rate of 1.67 × 10 -4s -1, i.e. elongation to failure was about 500% and the strain rate sensitivity, m value, was about 0.4. The activation energy of about 180 kJ/mol, which is nearly equal to that of grain boundary diffusion of Fe atoms in α-iron, was obtained for this plastic deformation. Furthermore the rolling contact fatigue life test was performed at room temperature under constant load. The fatigue life of SUJ 2 steel thermally cycled was found to be prolonged (about 2.5 times) as compared with that of conventional one.
著者
古谷 仁志 田川 哲哉 石川 孝司
出版者
一般社団法人 日本鉄鋼協会
雑誌
鉄と鋼 (ISSN:00211575)
巻号頁・発行日
vol.100, no.5, pp.678-687, 2014 (Released:2014-04-30)
参考文献数
23
被引用文献数
2

Tensile behaviors of cryogenic steels, which contain 0 to 12wt% nickel, were examined to obtain the fundamental knowledge related to the role of retained austenite in the improvement of fracture toughness. Although retained austenite of 8% and 12% nickel steel, which were manufactured by the special heat treatment composed of quenching, intermediate heat treatment, and tempering, was stable under the deep cooling at –196 ºC, it transformed to martensite by straining around 10% at –196 ºC. The strain hardening behavior was divided into two categories. One is that the maximum strain hardening appears just after yielding, then the strain hardening gradually decreases with increasing strain. It was related to 0% to 2% nickel steels, which include less retained austenite. Another is that the strain hardening increases just after yielding with the increase of strain, then it gradually decreases. In this case, higher strain hardening was derived. It was related to 5% to 12% nickel steels which included a certain amount of retained austenite. The increase of strain hardening under low temperature was attributed to the solute nickel and the formation of martensite, which act as a hard second phase, by the work induced martensitic transformation.
著者
大角 洸平 大塚 敏之 平田 光男 塩谷 政典
出版者
一般社団法人 日本鉄鋼協会
雑誌
鉄と鋼 (ISSN:00211575)
巻号頁・発行日
vol.99, no.4, pp.275-282, 2013 (Released:2013-03-26)
参考文献数
16
被引用文献数
1

In this paper, a control problem of temperature dispersion in steel cooling is formulated as model predictive control (MPC) of a probability density function (PDF). The input of MPC is optimized for dynamics of the PDF approximated by the Monte Carlo method, which is called particle MPC (PMPC). Simulation results of PMPC are presented to show the potential effectiveness of dispersion control.
著者
小野寺 秀博 阿部 太一 下野 昌人 小山 敏幸
出版者
一般社団法人 日本鉄鋼協会
雑誌
鉄と鋼 (ISSN:00211575)
巻号頁・発行日
vol.100, no.10, pp.1207-1219, 2014 (Released:2014-09-30)
参考文献数
116
被引用文献数
2 3

Computational materials science is an exciting field which holds much future potential. In this article, at first, the dramatic advances of the computational methodologies are briefly summarized at scales from the atomistic to macroscopic levels. Then, each coauthor introduces the three research fields in detail, (1) CALPHAD modeling supported by key experiments and first-principles calculation, (2) Studies on the phase transformation in alloys based on the MD simulations, and (3) Predictions of the microstructure evolution and the mechanical properties based on the phase-field method, where remarkable progresses have been attained.
著者
永田 和宏 古主 泰子 松原 章浩 國分(齋藤) 陽子 中村 俊夫
出版者
一般社団法人 日本鉄鋼協会
雑誌
鉄と鋼 (ISSN:00211575)
巻号頁・発行日
vol.105, no.4, pp.488-491, 2019 (Released:2019-03-31)
参考文献数
16
被引用文献数
1 1

The Japanese nails had been produced by the traditional ironmaking way of Tatara until the Edo period since the late of 6 Century. The Tatara is characterized as the ironmaking using very fine iron sand as the resources and is distinguished from the pre-modern ironmaking way in Europe using lump iron ore. The quality of the Japanese nails is affected from steel produced by Tatara in each age. The 14C ages of 3 Japanese nails were measured with accelerator mass spectrometry and calibrated to calendar years. Each 14C age provided plural calendar year periods with definite probabilities, and one of the periods determined in comparison with the history of temples and their repair records. The production ages of nails used in the Daibutuden of the Todaiji temple, the living quarters of the Manshuin temple and the Zaoudo of the Yoshino-Kinpusenji temple are before 1692, the 12 Century and before 1592, respectively, when they were repaired or reconstructed.