scholarly journals Steel sheets partnered with quenchable sheet in hot stamping of tailor-welded blanks and its application to separation prevention of fractured components

2020 ◽  
Vol 111 (3-4) ◽  
pp. 725-734
Author(s):  
Ken-ichiro Mori ◽  
Yasutaka Suzuki ◽  
Daisuke Yokoo ◽  
Michiya Nishikata ◽  
Yohei Abe
Keyword(s):  
Mechanical Properties ◽  
Phase Transformation ◽  
Mild Steel ◽  
Hot Stamping ◽  
High Strength ◽  
Boron Steel ◽  
Air Cooling ◽  
High Ductility ◽  
Steel Sheets ◽  
Tailor Welded Blanks

Abstract The phase transformation and mechanical properties of non-quenchable steels partnered with the quenchable boron steel in hot stamping of tailor-welded blanks were evaluated to produce tailored components with partially balanced strength and ductility. The effect of the forming start temperature after natural air cooling on the phase transformation and mechanical properties for 270 MPa mild steel, non-quenchable steel, 440 MPa high strength steel, and 22MnB5 steel sheets was examined, and the 270 MPa and non-quenchable sheets had enough ductility after hot stamping. Tailored components having a hardness of about 500 HV1 in the high strength zone and a total elongation of about 30% in the high ductility zone were hot-stamped from a tailor-welded blank composed of 22MnB5 and 270 MPa sheets. It was found that the 270 MPa mild steel sheet is sufficient as a partner sheet of tailor-welded blanks. In addition, the safety of hot-stamped components was heightened by welding a 22MnB5 main blank with a 270 MPa steel patch. Even if the main blank is fractured by a collision, the hot-stamped component is not separated by the 270 MPa patch having high ductility.

Thermal and Mechanical Characteristics of a HSLA Steel as Joint Partner for Hot Stamping Tailor Welded Boron Steel

2014 ◽  
Vol 1063 ◽  
pp. 104-107
Author(s):  
Bing Tao Tang ◽  
Qiao Ling Wang ◽  
Wei Zheng ◽  
Zheng Jun Yuan
Keyword(s):  
Mechanical Properties ◽  
Mechanical Characteristics ◽  
Hsla Steel ◽  
Hot Stamping ◽  
Boron Steel ◽  
Thermal And Mechanical Properties ◽  
Safety Requirements ◽  
Automobile Safety ◽  
Tailor Welded Blanks ◽  
Body Components

In order to further reduce the weight and at the same time guarantee the automobile safety, hot stamping of Tailor-Welded Blanks (TWBs), is developed recently to meet the environmental and safety requirements by supplying car structural body components with functionally optimized and tailored mechanical properties. In the article, an appropriate partner material for the quenchenable boron steel B1500HS based on the phase transformation and deformation behavior under process relevant conditions is determined. Microhardness is measured and metallographic is investigated. It is verified that the B340LA steel is an appropriate joint partner with ideal thermal and mechanical properties.

A novel approach to wear testing in hot stamping of high strength boron steel sheets

Wear ◽  
2013 ◽  
Vol 302 (1-2) ◽  
pp. 1319-1326 ◽  
Author(s):  
A. Ghiotti ◽  
F. Sgarabotto ◽  
S. Bruschi
Keyword(s):  
Hot Stamping ◽  
High Strength ◽  
Wear Testing ◽  
Boron Steel ◽  
Steel Sheets ◽  
Novel Approach

Prediction of Microstructure and Mechanical Properties in Hot Stamping

2014 ◽  
Vol 1063 ◽  
pp. 314-317
Author(s):  
Chao Wang ◽  
Bin Zhu ◽  
Yi Lin Wang ◽  
Yi Sheng Zhang
Keyword(s):  
Phase Transformation ◽  
Hot Stamping ◽  
Fuel Efficiency ◽  
Thin Sheet ◽  
High Strength ◽  
Transformation Model ◽  
Boron Steel ◽  
Stamping Process ◽  
Improved Model ◽  
Acceptable Agreement

Hot stamping process has been increasingly used in producing structural components of automobile to improve crash worthiness and fuel efficiency. Hot stamping process can produce ultimate tensile strength parts as high as 1500MPa. The high strength of hot –stamped components is attributed to the martensitic phase transformation which is transformed from austenite at elevated temperature. An improved model is developed based on Li’s phase transformation model to predict the austenite decomposition into ferrite, pearlite, bainite and martensite during arbitrary cooling paths for thin sheet boron steel. The simulated volume fractions and hardness profiles shows acceptable agreement to the corresponding experimental observations.

Indirect Hot Stamping of Boron Steel 22MnB5 for an Upper B-Pillar

2011 ◽  
Vol 314-316 ◽  
pp. 703-708
Author(s):  
Jun Ying Min ◽  
Jian Ping Lin ◽  
Li Jiu Xin ◽  
Jia Yue Li
Keyword(s):  
Phase Transformation ◽  
Cooling Rate ◽  
Hot Stamping ◽  
Tensile Tests ◽  
Uniaxial Tensile ◽  
Boron Steel ◽  
Heating Process ◽  
Air Cooling ◽  
Stamping Process ◽  
Vehicle Components

During the indirect hot stamping process of boron steel, the pre-deformed component undergoes air cooling, one-side-contact cooling and both-side-contact cooling phases successively. The effects of pre-deformation and cooling rate on the phase transformation should be understood before conducting indirect hot stamping experiments of vehicle components. Uniaxial tensile tests of boron steel at RT were carried out to obtain specimens with different pre-strain levels. Then they were heated to 900°C according to the indirect hot stamping process and quenching tests were performed on them at different cooling rates. Metallographic observations were performed on the quenched specimens and their hardness was measured. The results show that the pre-strain at RT has little influence on the phase transformation of boron steel. This is due to the dislocation structure introduced by deformation at RT recovered during the heating process and it is good for the indirect hot stamping. Upper B-pillar parts were first cold pre-formed, and then were heated and hot stamped. The microstructure and hardness results at different locations on the indirect hot stamped components are demonstrated qualified.

Heat Transfer in Hot Stamping of High-Strength Boron Steel Sheets

2014 ◽  
Vol 45 (4) ◽  
pp. 1192-1195 ◽  
Author(s):  
Zhiqiang Zhang ◽  
Xianshuang Li ◽  
Yong Zhao ◽  
Xiangji Li
Keyword(s):  
Heat Transfer ◽  
Hot Stamping ◽  
High Strength ◽  
Boron Steel ◽  
Steel Sheets

Experimental Assessment of High Temperature Formability of Boron Steel Sheet Manufactured With a Spring Compound Bending Die

2012 ◽  
Vol 134 (2) ◽  
Author(s):  
Yang Li ◽  
Yong-Phil Jeon ◽  
Chung-Gil Kang
Keyword(s):  
Mechanical Properties ◽  
Heating Temperature ◽  
Boron Steel ◽  
Hot Press ◽  
Forming Process ◽  
Steel Sheets ◽  
Press Forming ◽  
Bending Process ◽  
Tension Testing ◽  
Hot Press Forming

Bending behavior occurs in the hot press forming process, resulting in many cases of failure during forming. To address the problem of cracking and improve the formability and mechanical properties of boron steel sheets in the bending process, an experiment has been carried out by using a spring compound bending die. Also, a comparison has been made between the traditional U-bending die and the spring compound bending die with regard to formability. The influence of the parameters for hot press forming such as the heating temperature, punch speed, and die radii on the mechanical properties and microstructure was analyzed by tension testing and metallographic observations.

Deterioration of Mechanical Properties of High-Strength Pumpcrete after Exposure to High Temperatures

2010 ◽  
Vol 168-170 ◽  
pp. 564-569
Author(s):  
Guang Lin Yuan ◽  
Jing Wei Zhang ◽  
Jian Wen Chen ◽  
Dan Yu Zhu
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Heating Rate ◽  
High Strength Concrete ◽  
Heating Temperature ◽  
High Strength ◽  
Air Cooling ◽  
Test Results ◽  
Strength Deterioration ◽  
Residual Compressive Strength

This paper makes an experimental study of mechanical properties of high-strength pumpcrete under fire, and the effects of heating rate, heating temperature and cooling mode on the residual compressive strength(RCS) of high-strength pumpcrete are investigated. The results show that under air cooling, the strength deterioration speed of high-strength concrete after high temperature increases with the increase of concrete strength grade. Also, the higher heating temperature is, the lower residual compressive strength value is. At the same heating rate (10°C/min), the residual compressive strength of C45 concrete after water cooling is a little higher than that after air cooling; but the test results are just the opposite for C55 and C65 concrete. The strength deterioration speed of high-strength concrete after high temperature increases with the increase of heating rate, but not in proportion. And when the heating temperature rises up between 200°C and 500°C, heating rate has the most remarkable effect on the residual compressive strength of concrete. These test results provide scientific proofs for further evaluation and analysis of mechanical properties of reinforced-concrete after exposure to high temperatures.

Hot Stamping Processing Experiments of Quenchable Boron Steel

2008 ◽  
Vol 575-578 ◽  
pp. 299-304 ◽  
Author(s):  
Jun Bao ◽  
Zhong Wen Xing ◽  
Yu Ying Yang
Keyword(s):  
Heating Temperature ◽  
Hot Stamping ◽  
Cooling Water ◽  
High Strength ◽  
Processing Parameters ◽  
Boron Steel ◽  
Complicated Shape ◽  
Water Flow Velocity ◽  
Ultra High Strength Steel ◽  
Automotive Parts

The quenchable boron steel is a novel type of ultra high strength steel used for automotive parts so as to reduce the weight of the whole automobile. The hot stamping processing experiments for bending parts were studied. The influence of the hot stamping processing parameters, such as the heating temperature, the heat holding time and the cooling water flow velocity, on the mechanics properties and microstructure of the hot stamping parts is obtained. And then the optimal ranges of these parameters are determined, which provides a basis for the control of the hot stamping process applied in complicated shape parts’ production.

Erzeugung duktiler Bereiche beim Formhärten*/Production of ductile areas in hot stamping – Creating areas with reduced strength using a tempering station

2019 ◽  
Vol 109 (10) ◽  
pp. 750-754
Author(s):  
B. Behrens ◽  
S. Hübner ◽  
S. Yarcu ◽  
K. Wölki ◽  
H. Maier ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Hot Stamping ◽  
High Strength ◽  
Car Body

Formgehärtete Bauteile sind aufgrund ihres Leichtbaupotenzials im Karosseriebau etabliert. Jedoch ist die mechanische und thermische Fügbarkeit aufgrund der hohen Festigkeit stark eingeschränkt. Ein Ansatz zur Verbesserung der Fügeeigenschaften ist die Erzeugung von weichen Fügezonen. Zur gezielten Einstellung von lokal angepassten mechanischen Eigenschaften beim Formhärten wurde daher eine dem Platinenerwärmungsprozess nachgeschaltete Temperierungsstation entwickelt, um Platinen vor dem eigentlichen Formhärten im Hinblick auf eine lokale Entfestigung zu temperieren.   Due to their lightweight, hot-stamped components are established in car body manufacturing. However, high strength limits the application of mechanical and thermal joining operations. One approach to improving the joining properties is the production of ductile joining areas. To achieve locally varying mechanical properties, a tempering station has been developed that is suited to locally adapt the blank temperatures right after the oven process and thus prior to the hot stamping, resulting in tailored mechanical properties after the hot stamping operation.

Sign in / Sign up

Export Citation Format

Share Document