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.

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

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.

Numerical Modeling of Hot Press Forming Process of Boron Steel Tube

2010 ◽  
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

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

2011 ◽  
Vol 264-265 ◽  
pp. 241-247 ◽  
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.

Mechanical Characterization Behavior of Boron Steel Sheet in Hot Press Forming Process with Cooling System

2011 ◽  
Vol 264-265 ◽  
pp. 48-53
Author(s):  
S.H. An ◽  
Ki Young Kwon ◽  
Chung Gil Kang
Keyword(s):  
Heat Transfer ◽  
Cooling Rate ◽  
Material Properties ◽  
Cooling System ◽  
Boron Steel ◽  
Hot Press ◽  
Forming Process ◽  
Press Forming ◽  
Hot Press Forming ◽  
The Heat Transfer Coefficient

When cooling a boron sheet that has been heated to over 900 °C by hot press forming (HPF) process, the microstructure obtains a martensitic structure by controlling the cooling rate. HPF has advantages such as improvement in formability and material properties, and minimal springback of the formed material. The facts influenced by the cooling rate are determined by the heat transfer characteristics between the heated materials and the dies. In this study, controlling of the cooling rate is addressed by controlling the heat transfer coefficient of the material during the pressing process. This study demonstrates the material properties and microstructures of the formed material during the HPF process wherein cold dies are used to form the heated steel plate. This is achieved by varying the major forming conditions: the cooling rates, which is regarded as the most important process parameter.

scholarly journals Effect of initial blank temperature in hot press forming towards 22MnB5 springback failure

2019 ◽  
Vol 13 (2) ◽  
pp. 5137-5149
Author(s):  
C. H. Ng ◽  
C. F. Lai ◽  
S. N. M. Yahaya ◽  
S. Shamsudin ◽  
S. N. A. S. Ahmad ◽  
...  
Keyword(s):  
High Strength ◽  
Boron Steel ◽  
Hot Press ◽  
Forming Process ◽  
Quenching Rate ◽  
Press Forming ◽  
Initial Blank ◽  
Hot Press Forming ◽  
Formed Part ◽  
The Impact

The springback failure of ultra-high strength boron steel (22MnB5) in hot press forming (HPF) process was characterized under bending and membrane conditions. Hot press forming for U–shaped parts with ultra-high strength boron steel were experimented and simulated to study the effect of initial blank temperatures on springback failure in the automotive industry. The results specify the various preheated temperature of 22MnB5 blank effect toward springback occurrences with reference to hot press forming dies design. ANSYS Workbench was used to verify finite element (FE) simulations of the processes in order to consolidate the knowledge of springback. The validated numerical simulation model were used in analyzing the stress and strain distributions along the formed part in the FE models, it was found that the springback angle was related in averaging value throughout quenching, regardless of the forming conditions. Springback failure mainly caused dimension deviation in hot press form parts due to the impact of thermal restoring moments and quenching rate of hot press forming process.

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