The Experts below are selected from a list of 34983 Experts worldwide ranked by ideXlab platform
Ken-ichiro Mori - One of the best experts on this subject based on the ideXlab platform.
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minimisation of Heating time for full hardening in hot stamping using direct Resistance Heating
Journal of Manufacturing and Materials Processing, 2020Co-Authors: Tomoyoshi Maeno, Ken-ichiro Mori, Masato Sakagami, Yoshitaka Nakao, Ali TalebianarakiAbstract:To obtain enough hardness of the die-quenched products after hot stamping using direct Resistance Heating, the effects of the electrifying condition and initial microstructure of the quenchable steel sheet on hardness were examined in a hot bending experiment. The steel sheet was heated up to 900 °C in 3 to 10 s. The required Heating time was shortened by normalising heat treatment due to the fine grain size of the sheet. The standard deviation of the hardness of the sheet heated to 900 °C in 3.2 s without temperature holding at the austenitising temperature was 12 HV, whereas the deviation reduced to 5 HV for temperature holding at the austenitising temperature of 3 s.
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removal of thin oxide scale by ultrasonic cleaning with diluted hydrochloric acid in hot stamping of bare 22mnb5 sheet using Resistance Heating
Procedia Manufacturing, 2019Co-Authors: Tomoyoshi Maeno, Ken-ichiro Mori, Tomoki Ogihara, Tomohiro FujitaAbstract:Abstract A descaling process using ultrasonic cleaning with a diluted hydrochloric acid solution was developed to remove the thin oxide layer formed from the hot stamping of a bare 22MnB5 sheet using Resistance Heating. The oxide film removal performance and subsequent weldability and paintability were investigated. Since the oxide layer formed by Resistance Heating is thin, the oxide layer was successfully removed by ultrasonic cleaning with the acidic solution. The occurrence of spattering during Resistance spot welding was suppressed, and sufficient weld strength was obtained.
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inclusion of hot stamping operations in progressive die plate forging of tailored high strength gear part
The International Journal of Advanced Manufacturing Technology, 2017Co-Authors: Ken-ichiro Mori, Tomoyoshi Maeno, Makoto Tsuchiya, Tatsuhiro NanyaAbstract:Hot stamping operations of a quenchable steel sheet were included in progressive-die plate forging to produce a tailored high strength gear part without additional heat treatments. As process design for the inclusion, the former stages in the progressive-die operations for punching and trimming were cold stamping, and subsequently, Resistance Heating, blanking, forging and die quenching were performed. The plate was partially Resistance-heated with a pair of electrodes to produce a tailored gear part having high strength teeth and a ductile remainder. The tooth portion was uniformly heated around 1050 °C in the transversal current direction, and a gear part having teeth having 520 HV2 in hardness was produced. The quality of the teeth was improved by hot semi-blanking with local compression and cold scrap removing. It is found that the combined process of plate forging and hot stamping is useful to produce ultra-high strength steel parts.
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deep drawability and bendability in hot stamping of ultra high strength steel parts
Key Engineering Materials, 2016Co-Authors: Ken-ichiro Mori, Tomoyoshi Maeno, Yuzo YanagitaAbstract:The deep drawability and bendability in hot stamping of ultra-high strength steel parts were examined. Although the cold drawability is greatly influenced by the blank shape, the limiting drawing depths for the square and circular blanks were equal for hot stamping because of small flow stress. In hot hat-shaped bending using draw-and form-type tools, the effect of the blankholder force generated with the draw-type tools on the springback was small, and the seizure for the form-type tools was smaller than that of the draw-type tools. Since both edges in contact with the electrodes are not heated for Resistance Heating, cracks were caused at the edges for Resistance Heating in the transversal directions in hot stamping of an S-rail with form-type tools, and thus it is required to control deformation of the non-Heating zones.
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1 shot hot stamping of ultra high strength steel parts consisting of Resistance Heating forming shearing and die quenching
International Journal of Machine Tools & Manufacture, 2015Co-Authors: Ken-ichiro Mori, Tomoyoshi Maeno, Hiroaki Yamada, Hayato MatsumotoAbstract:Abstract A 1-shot hot stamping process consisting of Resistance Heating, forming, shearing and die quenching was developed to produce small- and medium-size ultra-high strength steel parts. A rectangular sheet was Resistance-heated to obtain a uniform distribution of temperature, and just after the end of Heating, a sequence of forming, shearing and die quenching was performed by one shot to prevent the drop in temperature. An ultra-high strength steel spur gear having a hardness of 540 HV2 was produced by 1-shot hot stamping composed of Heating, blanking and die quenching. The rollover was improved by partial compression of the blanked gear. An ultra-high strength stainless steel part having a hardness of 580 HV2 was produced by 1-shot hot stamping consisting of the Heating, bending, shearing and die quenching, and no springback and quenching distortion of the produced part were observed by holding at the bottom dead centre of the press. An operation for thickening the edge of the punched hole was included in 1-shot hot stamping to improve the strength of a product.
Tomoyoshi Maeno - One of the best experts on this subject based on the ideXlab platform.
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minimisation of Heating time for full hardening in hot stamping using direct Resistance Heating
Journal of Manufacturing and Materials Processing, 2020Co-Authors: Tomoyoshi Maeno, Ken-ichiro Mori, Masato Sakagami, Yoshitaka Nakao, Ali TalebianarakiAbstract:To obtain enough hardness of the die-quenched products after hot stamping using direct Resistance Heating, the effects of the electrifying condition and initial microstructure of the quenchable steel sheet on hardness were examined in a hot bending experiment. The steel sheet was heated up to 900 °C in 3 to 10 s. The required Heating time was shortened by normalising heat treatment due to the fine grain size of the sheet. The standard deviation of the hardness of the sheet heated to 900 °C in 3.2 s without temperature holding at the austenitising temperature was 12 HV, whereas the deviation reduced to 5 HV for temperature holding at the austenitising temperature of 3 s.
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removal of thin oxide scale by ultrasonic cleaning with diluted hydrochloric acid in hot stamping of bare 22mnb5 sheet using Resistance Heating
Procedia Manufacturing, 2019Co-Authors: Tomoyoshi Maeno, Ken-ichiro Mori, Tomoki Ogihara, Tomohiro FujitaAbstract:Abstract A descaling process using ultrasonic cleaning with a diluted hydrochloric acid solution was developed to remove the thin oxide layer formed from the hot stamping of a bare 22MnB5 sheet using Resistance Heating. The oxide film removal performance and subsequent weldability and paintability were investigated. Since the oxide layer formed by Resistance Heating is thin, the oxide layer was successfully removed by ultrasonic cleaning with the acidic solution. The occurrence of spattering during Resistance spot welding was suppressed, and sufficient weld strength was obtained.
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inclusion of hot stamping operations in progressive die plate forging of tailored high strength gear part
The International Journal of Advanced Manufacturing Technology, 2017Co-Authors: Ken-ichiro Mori, Tomoyoshi Maeno, Makoto Tsuchiya, Tatsuhiro NanyaAbstract:Hot stamping operations of a quenchable steel sheet were included in progressive-die plate forging to produce a tailored high strength gear part without additional heat treatments. As process design for the inclusion, the former stages in the progressive-die operations for punching and trimming were cold stamping, and subsequently, Resistance Heating, blanking, forging and die quenching were performed. The plate was partially Resistance-heated with a pair of electrodes to produce a tailored gear part having high strength teeth and a ductile remainder. The tooth portion was uniformly heated around 1050 °C in the transversal current direction, and a gear part having teeth having 520 HV2 in hardness was produced. The quality of the teeth was improved by hot semi-blanking with local compression and cold scrap removing. It is found that the combined process of plate forging and hot stamping is useful to produce ultra-high strength steel parts.
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deep drawability and bendability in hot stamping of ultra high strength steel parts
Key Engineering Materials, 2016Co-Authors: Ken-ichiro Mori, Tomoyoshi Maeno, Yuzo YanagitaAbstract:The deep drawability and bendability in hot stamping of ultra-high strength steel parts were examined. Although the cold drawability is greatly influenced by the blank shape, the limiting drawing depths for the square and circular blanks were equal for hot stamping because of small flow stress. In hot hat-shaped bending using draw-and form-type tools, the effect of the blankholder force generated with the draw-type tools on the springback was small, and the seizure for the form-type tools was smaller than that of the draw-type tools. Since both edges in contact with the electrodes are not heated for Resistance Heating, cracks were caused at the edges for Resistance Heating in the transversal directions in hot stamping of an S-rail with form-type tools, and thus it is required to control deformation of the non-Heating zones.
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1 shot hot stamping of ultra high strength steel parts consisting of Resistance Heating forming shearing and die quenching
International Journal of Machine Tools & Manufacture, 2015Co-Authors: Ken-ichiro Mori, Tomoyoshi Maeno, Hiroaki Yamada, Hayato MatsumotoAbstract:Abstract A 1-shot hot stamping process consisting of Resistance Heating, forming, shearing and die quenching was developed to produce small- and medium-size ultra-high strength steel parts. A rectangular sheet was Resistance-heated to obtain a uniform distribution of temperature, and just after the end of Heating, a sequence of forming, shearing and die quenching was performed by one shot to prevent the drop in temperature. An ultra-high strength steel spur gear having a hardness of 540 HV2 was produced by 1-shot hot stamping composed of Heating, blanking and die quenching. The rollover was improved by partial compression of the blanked gear. An ultra-high strength stainless steel part having a hardness of 580 HV2 was produced by 1-shot hot stamping consisting of the Heating, bending, shearing and die quenching, and no springback and quenching distortion of the produced part were observed by holding at the bottom dead centre of the press. An operation for thickening the edge of the punched hole was included in 1-shot hot stamping to improve the strength of a product.
Seijiro Maki - One of the best experts on this subject based on the ideXlab platform.
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warm and hot punching of ultra high strength steel sheet
Cirp Annals-manufacturing Technology, 2008Co-Authors: Ken-ichiro Mori, S. Saito, Seijiro MakiAbstract:Abstract Warm and hot punching using Resistance Heating was developed to improve the quality of sheared edges of an ultra high strength steel sheet. As the Heating temperature increased, the depth of the shiny burnished surface on the sheared edge increased and that of the rough fracture surface decreased. The rollover depth and burr height of the sheared edge became large above 800 °C. Although the roughness of the burnished surface was almost constant, the roughness of the fracture surface increased from 650 °C. The punching load was extremely reduced by the Heating, i.e. 40% of the cold punching load at 650 °C and 15% at 1070 °C. The local Resistance Heating of the shearing region was efficient for the warm and hot shearing. It was found that the warm and hot shearing of ultra high strength steel sheets is effective for improving the quality of the sheared edge and in reducing the shearing load.
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Resistance Heating characteristics of high strength steel sheet blank for hot press forming
Key Engineering Materials, 2007Co-Authors: Seijiro Maki, Yuuki Tanaka, Ken-ichiro MoriAbstract:Resistance Heating performance in some shaped blanks of high-strength steel sheet is examined by experiment and FE simulation, and the feasibility and effectiveness of the application of Resistance Heating to the hot press forming of high-strength steel sheet are discussed. The followings are made clear through this study. (1) A uniformly distributed current density is essential to uniform blank Heating. (2) For a certain shaped blank, no matter how the electrodes are disposed, uniform blank Heating is difficult. (3) A blank shape suitable for uniform Heating by a single pair of parallel electrodes is restricted to a rectangle.(4) In case a uniformly heated blank is required, two-piece simultaneous forming with point-symmetric die layout is recommended from the viewpoint of material utilization.
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improvement of product strength and formability in stamping of al mg si alloy sheets having bake hardenability by Resistance heat and artificial aging treatments
International Journal of Machine Tools & Manufacture, 2006Co-Authors: Seijiro Maki, Minoru IshiguroAbstract:Abstract Resistance heat and artificial aging treatments were introduced into a stamping operation to improve the product strength and formability of Al–Mg–Si alloy sheets having bake hardenability used for automobile body panels. In this treatment, the sheets undergo re-solution by Resistance heat treatment, composed of Resistance Heating and water quenching just before the stamping. Stamped sheets are artificially aged just after the stamping to increase product strength. In the experiment, Al–0.60% Si–0.74% Mg alloy sheets were chosen as an example of Al–Mg–Si alloy sheets having bake hardenability. The re-solution solution treatment of the sheets was sufficiently accomplished by rapid Resistance heat treatment, and formability of the sheets was improved. Hardness of the formed products was increased by artificial aging. It was found that the present process is effective in improving the product strength and formability of Al–Mg–Si alloy sheets having bake hardenability due to the compactness and rapidness.
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thermo mechanical treatment using Resistance Heating for production of fine grained heat treatable aluminum alloy sheets
Journal of Materials Processing Technology, 2006Co-Authors: Seijiro Maki, Minoru Ishiguro, Ken-ichiro Mori, Hiroyasu MakinoAbstract:Abstract A new thermo-mechanical treatment using Resistance Heating is devised to produce fine grained aluminum alloy sheets. To examine the effectiveness of the treatment, simulating experiments are conducted using a heat-treatable 6061 aluminum alloy, and the grain size, hardness property, and tensile properties are measured and compared with those of the conventionally heat-treated sheets. The results are summarized as follows: (1) Resistance Heating at a current density of about 100 A mm−2 realizes Heating the aluminum alloy sheet into the solution temperature range in 2 s, (2) complete achievement of rapid solution treatment by the Resistance Heating requires the condition that the precipitates exist finely in the matrix, (3) the new treatment decreases the grain size by approximately one-half but the mechanical properties are not remarkably improved.
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warm and hot stamping of ultra high tensile strength steel sheets using Resistance Heating
CIRP Annals, 2005Co-Authors: Ken-ichiro Mori, Seijiro MakiAbstract:A warm and hot stamping process of ultra high tensile strength steel sheets using Resistance Heating was developed to improve springback and formability. In this process, the decrease in temperature of the sheet before the forming is prevented by directly Heating the sheets set into the dies by means of the electrical Resistance, the so-called Joule heat. Since the Heating time up to 800°C is only 2 seconds, the Resistance Heating is rapid enough to synchronise with a press. The effects of the Heating temperature on the springback and formability of ultra high tensile strength steel sheets were examined. The springback in hat-shaped bending of the high tensile strength steel sheets was eliminated by Heating the sheet. In addition, the ultra sheet having a tensile strength of 980MPa was successfully drawn by the Heating. The Heating temperature is optimum around 600°C due to the small springback and oxidation and the increase in hardness.
Hayato Matsumoto - One of the best experts on this subject based on the ideXlab platform.
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1 shot hot stamping of ultra high strength steel parts consisting of Resistance Heating forming shearing and die quenching
International Journal of Machine Tools & Manufacture, 2015Co-Authors: Ken-ichiro Mori, Tomoyoshi Maeno, Hiroaki Yamada, Hayato MatsumotoAbstract:Abstract A 1-shot hot stamping process consisting of Resistance Heating, forming, shearing and die quenching was developed to produce small- and medium-size ultra-high strength steel parts. A rectangular sheet was Resistance-heated to obtain a uniform distribution of temperature, and just after the end of Heating, a sequence of forming, shearing and die quenching was performed by one shot to prevent the drop in temperature. An ultra-high strength steel spur gear having a hardness of 540 HV2 was produced by 1-shot hot stamping composed of Heating, blanking and die quenching. The rollover was improved by partial compression of the blanked gear. An ultra-high strength stainless steel part having a hardness of 580 HV2 was produced by 1-shot hot stamping consisting of the Heating, bending, shearing and die quenching, and no springback and quenching distortion of the produced part were observed by holding at the bottom dead centre of the press. An operation for thickening the edge of the punched hole was included in 1-shot hot stamping to improve the strength of a product.
Yazdan M Mehr - One of the best experts on this subject based on the ideXlab platform.
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spark plasma sintering of stellite 6 superalloy
Journal of Alloys and Compounds, 2019Co-Authors: Kiani M Khouzani, A Bahrami, Yazdan M MehrAbstract:Abstract This paper aims at studying microstructure and mechanical properties of spark plasma sintered (SPSed) Stellite®-6 cobalt-based superalloy. SPS is a sintering technique, based on a relatively fast Resistance Heating using a pulsed current. Fast sintering process, associated with minimum grain growth, results in excellent mechanical properties. Samples were sintered at temperatures ranging from 950 to 1100 °C. Microstructure of samples were studied using scanning electron microscope (SEM), energy-dispersive X-ray spectroscope (EDS), X-Ray diffraction (XRD), and optical microscope. Hardness, impact test, as well as room and high temperature compression tests were used to evaluate the effects of sintering temperature and duration on the mechanical properties of SPSed samples. Results show that optimum mechanical properties can be obtained after sintering at 1050 °C for 10 min. The correlation between sintering parameters, microstructure, and mechanical properties are discussed.
