巻号一覧
70 巻, 4 号
選択された号の論文の6件中1～6を表示しています
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論説
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河野 正道, 五十川 幸宏1999 年 70 巻 4 号 p. 249-254
発行日: 2000/03/27
公開日: 2000/03/27
ジャーナル フリーTo predict and control micro-structural evolution of Ni-based INCONEL Alloy 718 in hot working process is essential. Retained coarse grains in products are very difficult to be refined by subsequent heat treatment. In many papers, break down of casting structure is mostly focused. This paper treats constitutive equations for recrystallized structure. In order to quantify the influences of working conditions on micro-structural events correctly, homogeneous compression tests with cylindrical specimen were performed. The flow curves with heat generation during working were temperature compensated and constitutive equations of recrystallization were also established. To verify the validity of given equations, open die forging with small ring billets were carried out. In the result, the tendency between observation and thermal mechanical FEM simulation was in good agreement.抄録全体を表示PDF形式でダウンロード (823K) -
河野 正道, 五十川 幸宏, 川西 邦仁1999 年 70 巻 4 号 p. 255-260
発行日: 2000/03/27
公開日: 2000/03/27
ジャーナル フリーWorkhardable materials like high speed tool steels and super alloys have low ductility and narrow range of temperature suitable for rolling. In the hot profiled rolling of these materials, prevention of cracking in roughing process is significant technique. Considering the strong temperature dependence of deformability, keeping surface of materials high temperature is essential. And relatively homogeneous deformation should be also required. Then thermal mechanical FEM simulations of typical 5 roll pass designs for roughing mill were promoted. The distribution of strain, history of temperature, and mean normal stress at free surface of rolled materials were evaluated. In the view point of surface temperature, square-oval-square method was pointed as the most recommended process. The validity of given results were verified in commercial mass production. The improvement of productivity is supported by the FEM simulation.抄録全体を表示PDF形式でダウンロード (377K)
解説
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矢田 浩1999 年 70 巻 4 号 p. 261-269
発行日: 2000/03/27
公開日: 2000/03/27
ジャーナル フリーThe author first explains the fundamental metallurgical phenomena that occur in the hot rolling processes, introduces an example of the prediction model of microstructure and deformation stress during hot rolling, and explains how it is utilized in the actual practice. He then surveys the control processes of material properties in the wire rod and bar rolling, and finally discusses the future trend of control and prediction technologies in hot rolling including a new grain refinement process.抄録全体を表示PDF形式でダウンロード (805K)
技術資料
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川西 邦仁, 柴田 佳幸, 河野 正道1999 年 70 巻 4 号 p. 271-275
発行日: 2000/03/27
公開日: 2000/03/27
ジャーナル フリーFor a while ago, wires and rods of workhardable materials such as high speed tool steels and super alloys were hot rolled in Kawasaki plant with repeater mill. Their low capacity and high resistance of these materials to deform render them unsuitable for tandem rolling with larger billets. Moreover, the plants(melting, ingot break down, rolling, heat treating and pickling) spread over wide areas. Thus, further increase in physical distribution costs and tighter delivery date have become the issues. In order to reduce the manufacturing costs in wires and rods of workhardable materials, tandem hot rolling technique in Hoshizaki Plant of Daido Steel was in need. In roughing mill, roll pass design was considered in order to avoid crack on the surface. And in continuous train, entry speed to 1st pass was also controlled to reduce exposed time to air. Moreover, control of finishing speed prevented materials from internal melting. As a result recommended processes were established. Rolling shop was switched from Kawasaki bar and wire rod mill plant to Hoshizaki wire rod mill plant. Considerable improvement in productivity and costs was achieved.抄録全体を表示PDF形式でダウンロード (289K) -
田中 照章, 森 達也, 長瀬 忠広1999 年 70 巻 4 号 p. 277-282
発行日: 2000/03/27
公開日: 2000/03/27
ジャーナル フリーDaido completed the reconstruction of the Wire Rod Mill at Daido Chita Plant in October of 1998. The purpose was to increase the quality and performance of products and improve the productivity. This reconstruction covers from roughing to intermediate train and various new equipment and new technology have been introduced. In this report, the outline and new technology with this reconstruction in described.抄録全体を表示PDF形式でダウンロード (557K) -
鈴木 義一1999 年 70 巻 4 号 p. 283-288
発行日: 2000/03/27
公開日: 2000/03/27
ジャーナル フリーDisk shape free forged products are usually used in chemical processing industries as tube sheets which support tubes in reaction vessels. The tube sheets are required to have an excellent high temperature strength and high corrosion resistance. Usually the material is made of high Ni alloy and will be free forged for homogenous internal quality. In Daido Steel, we have developed RUM (Rotating Upsetting Method) and improved the quality of large free forged disks with combination of RUM and ordinary upset forging. With precisely controlled combination of upset forging ratios by RUM and ordinary upset forging, we have succeeded in producing Daido's largest diameter INCONEL Alloy 601 forged disk. The large diameter forged disk which is produced with this method has following characteristic. (1) Macro and Micro structures of cross-section show excellent internal homogeneity and satisfy the specified grain size requirement. (2) Due to the excellent grain size and internal homogeneity, the disk exhibits high rupture strength. Also the disk can be favorable compared with forged round bars in tensile strength and ductility at room temperature and 595°C. The disk shows excellent internal homogeneity and exhibits very little anisotropy.抄録全体を表示PDF形式でダウンロード (819K)
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