Hole-flange forming of high-strength steel sheet using one-step hot stamping-forging method

2016 ◽  
Vol 231 (1) ◽  
pp. 181-185 ◽  
Author(s):  
Fang-Sung Cheng
Keyword(s):  
Tensile Strength ◽  
High Strength Steel ◽  
Steel Sheet ◽  
Hot Stamping ◽  
High Strength ◽  
Successful Completion ◽  
Steel Sheets ◽  
One Step ◽  
Flange Forming ◽  
Hole Flanging

A process of one-step hot stamping-forging for increasing the tensile strength of the hole-flanging of the high-strength steel sheets with flange thickening was developed. In this proposed method, the high-strength steel sheet is directly formed within the designed die, which is simultaneously accompanied with a resistance heating, a hole punching, and the flanging and forging processes. The electrode material is SKD61. This material is not only used as the forming of the high-strength steel sheet but also directly served as the heating of the high-strength steel sheet within the die. The experimental results indicated that the high-strength steel sheet could be heated to 850 °C in 30 s by the SKD61 die. It demonstrates the successful completion of heating, hole punching, flanging and forging in a one-step process. Furthermore, it is found that the tensile strength of M18 tapped hole with forged part is increased by about 7.4% than that without forged part, and the breaking toughness is increased by about 33%.

Ultra-High Strength Steel Hot Stamping Technology and Devices

2014 ◽  
Vol 1063 ◽  
pp. 237-243
Author(s):  
Zhong De Shan ◽  
Qin Tai Yan ◽  
Chao Jiang ◽  
Wen Juan Rong
Keyword(s):  
Tensile Strength ◽  
High Strength Steel ◽  
Hot Stamping ◽  
Research Work ◽  
High Strength ◽  
Parameters Optimization ◽  
Systematic Research ◽  
China Academy ◽  
Ultra High Strength Steel ◽  
Vehicle Structure

Ultra High Strength Steel (UHSS) hot stamping technology is a special process which can enhance the steel tensile strength to 1500MPa. Appling this technology in producing vehicle structure parts can make car lighter and safer. In China there are more and more automobile enterprises adopt this technology. To master and extend the skill, China Academy of Machinery Science & Technology (CAM) have done systematic research, such as the strengthen mechanism of the steel, hot stamping key devices designing, forming and quenching integrated mould designing, stamping process parameters optimization, etc.. By now, CAM has mastered the mass production technology of vehicle parts, which can guarantee its shape and tensile strength, and produced such typical parts as door-beam, B pillar, etc.. The paper is an introduction of the research work and achievement about UHSS hot stamping developed by CAM.

704 Spot Welded Tensile Strength Characteristics in Ultra High Strength Steel Sheets

2016 ◽  
Vol 2016.53 (0) ◽  
pp. _704-1_-_704-2_
Author(s):  
Yu KITAHARA ◽  
Junya NAITO ◽  
Shota CHINZEI ◽  
Akira IBANO ◽  
Yuki SHIMIZU ◽  
...  
Keyword(s):  
Tensile Strength ◽  
High Strength Steel ◽  
High Strength ◽  
Strength Characteristics ◽  
Steel Sheets ◽  
Ultra High Strength Steel ◽  
Spot Welded

Mechanical Joining of Various Materials by Clinching Method

2015 ◽  
Vol 662 ◽  
pp. 205-208 ◽  
Author(s):  
Ľuboš Kaščák ◽  
Emil Spišák ◽  
Jacek Mucha
Keyword(s):  
High Strength Steel ◽  
Steel Sheet ◽  
Low Carbon Steel ◽  
Surface Preparation ◽  
High Strength ◽  
Low Carbon ◽  
Steel Sheets ◽  
Joint Properties ◽  
Wide Range ◽  
Grade Steel

Clinching is a simple, cheap and efficient method of joining that enables to join two or more sheets without any additional elements such as rivets, bolts or nuts. In addition, clinching does not require a surface preparation e.g. drilling (riveting), cleaning and roughening of the surface (adhesive boding) and other types of surface preparations (arc welding). Clinching is utilized in a wide range of applications and can be applied to different materials such as low carbon steel sheets, high-strength steel sheets, aluminium alloys, magnesium alloys. The paper presents the results of evaluation of clinched joint properties. The advanced high-strength steel sheet DP600 in combination with the drawing grade steel sheets DC06, DX51D+Z and high-strength low alloy steel sheet H220PD were used for experiments. The influence of position of the sheets relative to the punch and die of the tool on the carrying capacities of the clinched joints was observed as well. The tension test and microhardness test were used for the evaluation of clinched joint properties.

Direct Punching in Inclined Ultra-High Strength Steel Sheets

2014 ◽  
Vol 622-623 ◽  
pp. 1051-1057 ◽  
Author(s):  
Yohei Abe ◽  
Ken Ichiro Mori ◽  
Shigehiro Nakanoshita ◽  
Purwo Kadarno
Keyword(s):  
High Strength Steel ◽  
Steel Sheet ◽  
High Strength ◽  
Bottom Edge ◽  
Steel Sheets ◽  
Sheared Edge ◽  
Ultra High Strength Steel ◽  
Grade Steel ◽  
Inclined Sheet

A direct punching of inclined ultra-high strength steel sheets having low ductility was carried out to improve the quality of the sheared edge. In the direct punching of an inclined sheet, the contact between the sheet and punch became gradual because of touch from the bottom edge of the punch, and thus the sheared portion tended to bend in the latter half of punching. As the strength of the sheet increased, defects such as burr and secondary burnished surface were occurred around the sheared edge due to the low ductility. The range of direct punching for sheared edge without defects was shown for the high strength steel sheets. To prevent the occurrence of defects, a punch having inclined bottom was used. In this punch, the contact with the sheet was changed, the uniform contact with the inclined bottom was given. In the punch having the inclined bottom, the secondary burnished surface in the edge of 980 MPa grade steel sheet was prevented.

Reduction of Springback in Hat Channel with High-Strength Steel Sheetby Stroke Returning Deep Drawing

2013 ◽  
Vol 554-557 ◽  
pp. 1320-1330 ◽  
Author(s):  
Taro Geka ◽  
Masayuki Asakura ◽  
Takuma Kiso ◽  
Takashi Sugiyama ◽  
Masato Takamura ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Deep Drawing ◽  
High Strength Steel ◽  
High Strength ◽  
New Method ◽  
Dual Phase ◽  
High Tensile Strength ◽  
Blank Holder ◽  
Steel Sheets

This study investigated the twisting phenomenon in curved hat channel products made of dual-phase 980-MPa-class high-tensile-strength steel sheets. The stroke returning deep drawing (SRDD) method was proposed to deal with twisting. In this new method, after the punch reaches the bottom dead point, it returns to a certain drawing height without the blank holder being removed. With the application of the SRDD method, twisting hardly occurred, but sidewall curl increased. A two-step SRDD was then proposed to reduce the sidewall curl of SRDD products. In the two-step SRDD method, a stroke returning process is carried out in two steps under different conditions. The results showed that the two-step SRDD method reduced the sidewall curl and twist simultaneously.

Development of Ultra-High Strength Steel Sheets with Tensile Strength of 980MPa

2007 ◽  
Author(s):  
Nobuhiro Fujita ◽  
Toshiki Nonaka ◽  
Toshimasa Tomokiyo ◽  
Hirokazu Taniguchi ◽  
Koichi Goto ◽  
...  
Keyword(s):  
Tensile Strength ◽  
High Strength Steel ◽  
High Strength ◽  
Steel Sheets ◽  
Ultra High Strength Steel
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