Corrosion Assessment for Boron Steel Weldments Prepared by Overlap Welding and Successive Hot Press Forming Processes

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.

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Hardness Prediction of Tailor Rolled Blank in Hot Press Forming Using Quench Factor Analysis

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.729.110 ◽

2017 ◽

Vol 729 ◽

pp. 110-114

Author(s):

Jae Hong Kim ◽

Dae Cheol Ko ◽

Byung Min Kim

Keyword(s):

Factor Analysis ◽

Fe Simulation ◽

Boron Steel ◽

Rear Side ◽

Cooling Curves ◽

Hot Press ◽

Tailor Rolled Blank ◽

Side Member ◽

Press Forming ◽

Hot Press Forming

This paper aims to predict the hardness of hot formed part for tailor rolled blank (TRB) by the FE-simulation coupled with quenching factor analysis (QFA). Dilatometry test of boron steel is performed at various range of cooling rates from 0.2 to 100°C/s using the dilatometer with forced air cooling system. The dilatometry test provides a hardness data according to cooling curves which are used to determine the material constants (K1~K5) of QFA and the time‒temperature‒property (TTP) diagram of boron steel. Then, FE‒simulation of hot press forming is conducted to predict the cooling curves of hot formed TRB part with a thickness combination of thicker 1.6mm and thinner 1.2mm which is called as rear side member of automotive component. The cooling curves of FE-simulation are applied to predict the hardness of hot formed rear side member using the QFA. Also, experiment of hot press forming is performed to verify the predicted results and to examine the effect of cooling curves on the hardness.

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Flow characteristics of aluminum coated boron steel in hot press forming

Transactions of Nonferrous Metals Society of China ◽

10.1016/s1003-6326(08)60376-3 ◽

2009 ◽

Vol 19 (4) ◽

pp. 913-916 ◽

Cited By ~ 27

Author(s):

Jeong-Hwan JANG ◽

Jae-Ho LEE ◽

Byeong-Don JOO ◽

Young-Hoon MOON

Keyword(s):

Flow Characteristics ◽

Boron Steel ◽

Hot Press ◽

Press Forming ◽

Hot Press Forming

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Hot Press Forming of 22MnB5 Steel Using Full Factorial Design of Experiment (DOE)

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1024.243 ◽

2014 ◽

Vol 1024 ◽

pp. 243-246 ◽

Cited By ~ 1

Author(s):

Nuraini Aziz ◽

Syarifah Nur Aqida

Keyword(s):

Design Of Experiment ◽

Research Work ◽

Cooling Water ◽

High Hardness ◽

Maximum Load ◽

Hydraulic Press ◽

Boron Steel ◽

Hot Press ◽

Press Forming ◽

Hot Press Forming

This paper presents optimisation of hot press forming using design of experiment for high hardness properties at maximum cooling water temperature and minimum quenching time. Samples were boron steel blanks of 60x50 mm dimension. Hot press forming was conducted using a hydraulic press machine with 20 tonne maximum load. Results of this research work show that parameters obtained by single response optimization through desirability analysis route will increase hardness by 66.72%. The hardness properties of samples were between 477 and 551.4 HV(0.1). These findings were important to design tailored ultra-high strength automotive components at different process parameter settings and to reduce production cost consumption and improve production rate.

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Simulation of Thermal Distortion in Hot Press Forming with Dissimilar Material TWB

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1063.330 ◽

2014 ◽

Vol 1063 ◽

pp. 330-333

Author(s):

Hyun Ho Bok ◽

Jong Won Choi ◽

Myoung Gyu Lee ◽

Frédéric Barlat ◽

Dong Jin Kim

Keyword(s):

Shape Change ◽

Element Model ◽

Boron Steel ◽

Air Cooling ◽

Thermal Distortion ◽

Hot Press ◽

Steel Sheets ◽

Press Forming ◽

Hot Press Forming ◽

Micro Alloyed Steel

In order to predict the shape change in hot press forming of a TWB made with HPF1470 boron steel and HSLA340 micro-alloyed steel sheets, a coupled thermo-mechanical-metallurgical finite element model was developed to simulate the process. The simulation consisted of air cooling, forming, die-quenching and, finally, by a treatment designed to relax residual stresses. It is shown in this paper that the experimentally observed distortion in the TWB part was reasonably captured by the simulations.

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Characterization of the aluminium coating layer in the hot press forming of boron steel

Proceedings of the Institution of Mechanical Engineers Part B Journal of Engineering Manufacture ◽

10.1243/09544054jem1464 ◽

2009 ◽

Vol 224 (1) ◽

pp. 87-93 ◽

Cited By ~ 5

Author(s):

J H Jang ◽

B D Joo ◽

C J Van Tyne ◽

Y H Moon

Keyword(s):

Coating Layer ◽

Boron Steel ◽

Hot Press ◽

Press Forming ◽

Hot Press Forming ◽

Aluminium Coating

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Numerical Modeling of Hot Press Forming Process of Boron Steel Tube

10.1063/1.3457521 ◽

2010 ◽

Cited By ~ 1

Author(s):

Oh Suk Seo ◽

Suk Jin Yoon ◽

Chang Hee Suh ◽

Heon Young Kim ◽

F. Barlat ◽

...

Keyword(s):

Numerical Modeling ◽

Steel Tube ◽

Boron Steel ◽

Hot Press ◽

Forming Process ◽

Press Forming ◽

Hot Press Forming

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The Effect of Cooling Rate on Mechanical Properties of 22MnB5 Steel Sheet during Hot Press Forming

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.264-265.241 ◽

2011 ◽

Vol 264-265 ◽

pp. 241-247 ◽

Cited By ~ 1

Author(s):

Ki Young Kwon ◽

Nak Hyun Kim ◽

Chung Gil Kang

Keyword(s):

Mechanical Properties ◽

Steel Sheet ◽

Cooling Water ◽

High Strength Steels ◽

High Strength ◽

Hydraulic Press ◽

Boron Steel ◽

Hot Press ◽

Press Forming ◽

Hot Press Forming

There has been a growing usage of high strength steels (HSS), particularly in automobile applications mainly as structural parts in view of their light weight and high strength properties. These materials are also being considered for dynamic applications. However, the multi-phase microstructure, which is at the base of the strengthening mechanisms in most of these steels, leads to unacceptably high stresses during forming and significant springback phenomena, thus making traditional sheet metal forming technologies unsuitable. To avoid the disadvantages, a new process method was introduced – Hot Press Forming. Hot press forming (HPF) process is a forming method which can provide various advantages such as excellent mechanical properties and formability, good weldability and little springback. Here, the experiment parameters which include locations of the cooling holes and the flow rate of the cooling water play an important role in the HPF process. In this paper, the Al-Si coated boron steel sheet was researched by heating it up to 930oC for 5 min and formed by a hydraulic press. In this study, microstructural evolutions and the associated mechanical properties were investigated in terms of the flow rates of the cooling water.

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Hydrogen Absorption and Desorption Behavior on Aluminum-Coated Hot-Stamped Boron Steel during Hot Press Forming and Automotive Manufacturing Processes

Materials ◽

10.3390/ma14216730 ◽

2021 ◽

Vol 14 (21) ◽

pp. 6730

Author(s):

Hye-Jin Kim ◽

Hyun-Yeong Jung ◽

Seung-Pill Jung ◽

Ji-Hee Son ◽

Joo-Sik Hyun ◽

...

Keyword(s):

Hydrogen Absorption ◽

Hot Stamping ◽

Boron Steel ◽

Hot Press ◽

Diffusible Hydrogen ◽

Automotive Manufacturing ◽

Press Forming ◽

Hot Press Forming ◽

Pre Treatment ◽

Grade Steel

Our study mainly focused on diffusible hydrogen in aluminum–silicon-coated hot-stamped boron steel during a hot press forming process and in pre-treatment sequential lines of the automotive manufacturing process using a thermal desorption spectroscopy (TDS) technique. First, in the hot stamping procedure, as the soaking time increased in the heating furnace at a specific dew point when austenitizing, a high concentration of diffusible hydrogen was absorbed into the hot-stamped boron steel. Based on the TDS analysis of hydrogen absorbed from hot stamping, the activation energy value of hydrogen trapping in 1.8 GPa grade steel is lower than that of 1.5 GPa grade steel. This means that diffusible hydrogen can be more easily diffused into defective sites of the microstructure at a higher level of the tensile strength grade. Second, in sequential pre-treatment lines of the automotive manufacturing process, additional hydrogen did not flow into the surface, and an electro-deposition process, including a baking procedure, was effective in removing diffusible hydrogen, which was similar to the residual hydrogen of the as-received state (i.e., initial cold rolled blank). Based on these results, the hydrogen absorption was facilitated during hot press forming, but the hydrogen was sequentially desorbed during automotive sequential lines on aluminum-coated hot-stamped steel parts.

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