著者

植田 芳信 佐山 惣吾 西川 泰則 鈴木 良和 信岡 聡一郎

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.68, no.14, pp.2046-2048, 1982 (Released:2009-06-19)

被引用文献数

3

著者

Noriyuki Tsuchida Taiji Kawahata Eiichiro Ishimaru Akihiko Takahashi Hiroshi Suzuki Takahisa Shobu

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.53, no.7, pp.1260-1267, 2013 (Released:2013-08-20)

参考文献数

27

被引用文献数

3 26

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To investigate the tensile deformation behavior of a lean duplex stainless steel (S32101) from the viewpoints of plastic deformability among phases or grains, we performed static tensile tests, in situ neutron diffraction, and white x-ray diffraction experiments at room temperature. In the static tensile tests, the S32101 steel displayed a larger uniform elongation and a better tensile strength–uniform elongation balance than a commercial SUS329J4L duplex stainless steel. A larger uniform elongation of S32101 is associated with the macroscopic work hardening behavior that a work hardening rate higher than the flow stress can maintain up until high true strains. From the experimental results of synchrotron radiation white x-ray diffraction experiments, the hard phase of S32101 was changed from the ferrite (α) phase to austenite (γ) one during tensile deformation. This led to a larger stress partitioning between the phases at the latter stage of deformation. From the experimental results of in situ neutron diffraction, it was found that the stress partitioning of the γ phase in the S32101 was the largest among the present results. Therefore, the larger work hardening rate of S32101 can be explained by the large stress partitioning of the γ phase, that between γ and α phases and γ volume fraction.

著者

Nirsanametla Yadaiah Swarup Bag

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.52, no.11, pp.2069-2075, 2012 (Released:2012-11-15)

参考文献数

40

被引用文献数

5 39

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Double-ellipsoidal volumetric heat with Gaussian distribution of heat intensity is one of the most popular heat source model used in fusion welding process simulations. However, the major difficulty of this kind of heat source model is to define the parameters before start of simulation. It is common practice to define the heat source parameters from experimental measurement of weld dimensions for a particular welding condition that meet the demand of two parameters i.e. weld width and penetration. Till date, the definition of front and rear length of double ellipsoidal is to-some-extent arbitrary in linear welding. A sensitivity analysis shows that this ratio has significant effect on weld dimensions as well as thermal distortion and residual stress of final weld joint. This problem has been addressed in present work where the optimum value of the ratio of front and rear length of double ellipsoidal heat source model is designed within the kernel of an integrated optimization algorithm. The ratio is assumed as function of weld velocity and a suitable functional form is designed over a range of welding current and velocity. The proposed trend of ratio along with optimum values demonstrate fair agreement of experimentally measured weld dimensions for linear gas tungsten arc (GTA) welding process. 3D finite element model of thermal and mechanical analysis is developed and assuming elasto-plastic response of material. Temperature dependent material properties along with latent heat of melting and solidification are incorporated in numerical simulation.

著者

水上 英夫 林 宏太郎 沼田 光裕 山中 章裕

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.9, pp.457-466, 2011-09-01 (Released:2011-09-06)

参考文献数

50

被引用文献数

1 8

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Solid–liquid interfacial energy of steel during solidification was measured predicted from the both experimental techniques of unidirectional solidification and thermal analysis applying the dendrite growth model and heterogeneous nucleation model. Solid–liquid interfacial energy changed depending on primary phase during solidification, i.e., that of primary δ phase was larger than that of γ phase. When the primary phase was the same, solid–liquid interfacial energy increased with increasing carbon content. Primary dendrite arm spacing changed depending on solid–liquid interfacial energy. A trace amount of bismuth which had the effect of a decrease in the solid–liquid interfacial energy of steel during solidification decreased primary and secondary dendrite arm spacing, significantly.

著者

小澤 純夫 月橋 文孝

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.96, no.12, pp.706-713, 2010-12-01 (Released:2010-12-25)

参考文献数

24

被引用文献数

4

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The Utility of Stock hypothesis, which assumes that an in-use stock of constructional material is a function of GDP, was formulated and a clear correlation between the world steel stock and the world GDP led to the estimation that the world demand for iron ore (primary iron) depends not on the volume of GDP but on the variation of GDP, as already reported. It also became clear that the flow of primary iron has the controlling effect on the world production of crude steel. In this study, the prediction power of the Utility of Stock hypothesis is verified. Based on the verification, the global demand for iron source until 2050 is projected by deciding a world 1-region model.

著者

小澤 純夫 林 誠一 月橋 文孝

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.95, no.6, pp.522-530, 2009-06-01 (Released:2009-08-15)

参考文献数

19

被引用文献数

4 5

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To forecast iron source demand, the Intensity of Use hypothesis, which assumes that material consumption per capita is a function of GDP per capita, is the most dominant theory in existing studies. However, this hypothesis is not effective for a world one-region model of iron sources. Therefore, we focused our attention on utility, and we suppose that economic growth is a major driver to increase the utility. As the utility of steel sustains for ages after purchase, we formulate the Utility of Stock hypothesis, which assumes that the in-use steel stock is a function of GDP. In this study, the world steel stock was computed and the Utility of Stock hypothesis was tested. Clear correlation is found between the steel stock and the GDP. It leads to the estimation that the world demand for iron ore depends not on the volume of GDP but on the variation of GDP. For the first time with total world figures, the result enables us to rationalize the recent decoupling between the world growth of iron source demand and the economic growth.

著者

小澤 純夫 月橋 文孝

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.95, no.10, pp.710-719, 2009-10-01 (Released:2009-12-10)

参考文献数

21

被引用文献数

7 12

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The Utility of Stock hypothesis, which assumes that the in-use stock of constructional material is a function of GDP, was formulated and the clear correlation between the world steel stock and the GDP led to the estimation that the world demand for iron ore (primary iron) depends not on the volume of GDP but on the variation of GDP, as already reported. In this study, the world steel stock in use is computed. Sensitivity analyses are conducted to show the effect of lower reliable data such as the usage period (lifetime) of iron-containing final products. Clear correlation is found between the in-use steel stock and the steel stock. Hence, the Utility of Stock hypothesis is verified.