Cold Rolling Technique for Eliminating Cutting Process in Manufacturing Precise Product Using Non-Heat-Treated Micro Alloys

2005 ◽  
Vol 475-479 ◽  
pp. 3235-3238 ◽  
Author(s):  
Seo Gou Choi ◽  
Duk Jae Yoon ◽  
Geun An Lee ◽  
Hee Woong Lee ◽  
Kyoung Hoan Na
Keyword(s):  
Alloy Steel ◽  
High Strength ◽  
Paper Analysis ◽  
Work Piece ◽  
Cross Wedge Rolling ◽  
Forming Process ◽  
Cold Forming ◽  
Heat Treated ◽  
Plastic Forming ◽  
Alloy Steels

In general micro alloy steel have the higher strength relative to conventional steels, which limits the utilization of conventional plastic forming processes. Incremental forming processes are more suitable for cold forming of such a high strength material. In particular, cold cross wedge rolling (CWR) can be a potential tool to fabricate axi-symmetric components with multi steps using high strength micro alloy steel. Obviously, optimization of die shape design is a crucial factor to apply cold cross wedge rolling to micro alloy steels. In this regards, a simulation-based process design using an elasto-plastic FEM has been carried out in order to obtain an optimum die shape for cold cross wedge rolling in this paper. Analysis results provided that the stretching angle and the shoulder angle at knifing and guiding zones were significant parameters for the stable forming process. It was demonstrated that proper stretching and shoulder angles reduced an excessive slip between a work piece and die in CWR process despite the condition of the low friction coefficient.

Flow Curves Prediction of Heat Treated Boron Alloy Steels for Hot Stamping Process

2015 ◽  
Vol 658 ◽  
pp. 81-85
Author(s):  
Prapatsorn Srithananan ◽  
Pongpan Kaewtatip ◽  
Vitoon Uthaisangsuk
Keyword(s):  
Alloy Steel ◽  
Hot Stamping ◽  
High Strength Steels ◽  
High Strength ◽  
Optical Microscope ◽  
Stress Strain ◽  
Flow Curves ◽  
Press Hardening ◽  
Heat Treated ◽  
Alloy Steels

Automotive parts made of ultra-high strength steels (UHSS) have been increasingly produced by hot stamping or press hardening of boron alloy steel. In case of novel hot formed components with tailored properties, different heating cycles needed to be applied for different zones, in which varying microstructure characteristics were generated. Mechanical properties of these parts were thus precisely controlled by the microstructure constituents. In this work, stress-strain behaviors of a boron alloy steel undergoing different heat treatment conditions with respect to that modified hot stamping procedure were predicted. Firstly, boron alloy steel sheet specimens were heated up to the austenitization temperature. Afterwards, they were abruptly cooled down to the bainitic temperature range, held for different holding times and finally cooled to room temperature. The microstructures obtained from each condition were characterized by optical microscope (OM) using color tint etching. The stress-strain responses of all generated microstructures were determined by tensile test. By the modeling, flow curves of the individual single phases were described taking into account a dislocation theory based model and their chemical composition. Subsequently, effective flow curves of the heat treated boron alloy steels were calculated by means of the isostrain and non-isostrain method and were finally compared with the experimentally determined curves.

Optimization of the Heat Treatment Layout and Blank Outline of THTB

2013 ◽  
Vol 554-557 ◽  
pp. 2465-2471 ◽  
Author(s):  
Michael Lechner ◽  
Andreas Kuppert ◽  
Hinnerk Hagenah ◽  
Marion Merklein
Keyword(s):  
Heat Treatment ◽  
High Strength ◽  
Local Heat ◽  
Forming Limit ◽  
Forming Process ◽  
Cold Forming ◽  
New Approach ◽  
Heat Treated ◽  
Generic Term ◽  
Definition Of

Tailored heat treated blanks (THTB) is the generic term for an innovative approach to enhance the formability of blanks made out of high strength steel or aluminum alloys. Key idea of the technology is the adaption of the mechanical properties by a local heat treatment. Based on the new property distribution, the material flow during the forming operation can be improved and the forming limit can be enhanced. In comparison to conventional temperature assisted approaches the forming is performed at room temperature and therefore all advantages of a cold forming process can be used. Most challenging within the application is the definition of the heat treatment layout. Up to now the layout is dimensioned in a time-consuming trial and error procedure. In this paper a new approach for the automatic optimization of the heat treatment layout and the blank outline is presented.

Analysis on Temperature Field of Work-Piece during Cross Wedge Rolling

2011 ◽  
Vol 230-232 ◽  
pp. 352-356
Author(s):  
Wen Ke Liu ◽  
Kang Sheng Zhang ◽  
Zheng Huan Hu
Keyword(s):  
Finite Element ◽  
Temperature Field ◽  
Metal Flow ◽  
Work Piece ◽  
Contact Deformation ◽  
Cross Wedge Rolling ◽  
Forming Process ◽  
Rigid Plastic ◽  
Finite Element Software ◽  
Deform 3D

Based on the rigid-plastic deformation finite element method and the heat transfer theories, the forming process of cross wedge rolling was simulated with the finite element software DEFORM-3D. The temperature field of the rolled piece during the forming process was analyzed. The results show that the temperature gradient in the outer of the work-piece is sometimes very large and temperature near the contact deformation zone is the lowest while temperature near the center of the rolled-piece keeps relatively stable and even rises slightly. Research results provide a basis for further study on metal flow and accurate shaping of work-piece during cross wedge rolling.

scholarly journals Numerical and Experimental Study on the Thermodynamic Coupling of Ti-6Al-4V Blade Preforms by Cross Wedge Rolling

Metals ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 1054 ◽  
Author(s):  
Hongchao Ji ◽  
Jianwei Dong ◽  
Long Xin ◽  
Xiaomin Huang ◽  
Jinping Liu
Keyword(s):  
Titanium Alloy ◽  
Metal Flow ◽  
High Strength ◽  
High Heat ◽  
Cross Wedge Rolling ◽  
Forming Process ◽  
Finite Element Software ◽  
Distribution Laws ◽  
Aero Engines ◽  
Thermodynamic Coupling

Titanium alloy possesses high strength, good corrosion resistance, and high heat resistance; thus, it is widely used in the aerospace and other fields. Blades of titanium alloy are important components of aero-engines and are essential to the engines operation. In this work, a Ti-6Al-4V blade was formed by cross wedge rolling (CWR) to realize the near net-shape of an aero-engine blade. First, thermal simulation experiments of Ti-6Al-4V were carried out to obtain the thermal deformation constitutive equation of the alloy. The finite element software Deform-3D was then used to simulate the thermodynamic coupling of the forming process, and the metal flow, temperature, and stress–strain distribution laws during the forming process were analyzed. Finally, experimental verification of the Ti-6Al-4V blade was carried out by using an H500 CWR mill. The results revealed the feasibility of applying CWR to preform Ti-6Al-4V blades.

Advanced FE model validation of cold-forming process using DIC: Air bending of high strength steel

2020 ◽  
Vol 13 (3) ◽  
pp. 409-421 ◽  
Author(s):  
S. Gothivarekar ◽  
S. Coppieters ◽  
A. Van de Velde ◽  
D. Debruyne
Keyword(s):  
Model Validation ◽  
High Strength Steel ◽  
High Strength ◽  
Fe Model ◽  
Forming Process ◽  
Cold Forming ◽  
Air Bending

Effects of thread rolling processing parameters on mechanical properties and microstructures of high-strength bolts

2020 ◽  
Vol 62 (10) ◽  
pp. 1017-1024
Author(s):  
Serkan Aktas ◽  
Yasin Kisioglu
Keyword(s):  
Mechanical Properties ◽  
Low Carbon Steel ◽  
High Strength ◽  
Rolling Process ◽  
Processing Parameters ◽  
Industrial Applications ◽  
Low Carbon ◽  
Forming Process ◽  
Cold Forming ◽  
Thread Rolling

Abstract Bolt production with a grade of 10.9 class quality made from AISI4140 material with a low thread rolling index is usually implemented in accordance with the thread rolling method (cold forming) in industrial applications. In this method, the effects of die revolutions and multiple passes are unknown in the thread forming process as the devices are usually operated with respect to geometrical dimensions but not the mechanical properties and microstructures of the material. In the literature there are few studies on microstructures of low-carbon steel having a higher thread rolling index in bolt production. This study experimentally examined the effects of the processing parameters on the mechanical properties and microstructures. Parameters such as forming speed and single or multi-pass influences were considered in the production of M12 × 1.75 and M20 × 2.5 fasteners widely used in industrial applications. The experiments identified the behavior of the mechanical properties, microstructures and micro-hardness of the AISI4140 material at two forming speeds (rpm) and three passes in the thread rolling process. Thus, significantly sensible outcomes as a function of processing parameters were obtained considering the thread strength viewpoints.

Development of Manufacturing Process Using Cold Incremental Forming Technique for Micro-Alloyed Non-Heat-Treated Material

2006 ◽  
Vol 510-511 ◽  
pp. 254-257 ◽  
Author(s):  
Hyoung Wook Lee ◽  
Geun An Lee ◽  
Duk Jae Yoon ◽  
Seo Gou Choi ◽  
Nak Kyu Lee ◽  
...  
Keyword(s):  
Incremental Forming ◽  
Rolling Process ◽  
Carbon Steels ◽  
Cold Forging ◽  
Cross Wedge Rolling ◽  
Forming Process ◽  
Heat Treated ◽  
Production Stages ◽  
Automotive Part ◽  
Micro Alloyed Steel

A micro-alloyed non-heat-treated material does not need post heat treatment processes such as quenching and tempering after the forming process in production stages. This material can be called a green material since it can reduce industrial costs and harmful pollutants generated from post heat treatments. In this paper, near-net-shape forming processes were studied in order to make an automotive part using a micro-alloyed material. The cold forging technique using a former was utilized for the main shaping, and the cold incremental forming technique using a cross wedge rolling machine was adopted for the enhancement of strength and the final shaping of the part. In order to get more adequate process, the cross wedge rolling process is compared to the swaging process for the micro-alloyed steel and general carbon steels through experiments.

Three Point Bend Performance of Solutionized, Die Quenched and Heat Treated AA7075 Beam Members

2014 ◽  
Vol 794-796 ◽  
pp. 431-436 ◽  
Author(s):  
Alexander Bardelcik ◽  
Alexandre Bouhier ◽  
Michael J. Worswick
Keyword(s):  
Mechanical Properties ◽  
Peak Load ◽  
Natural Aging ◽  
High Strength ◽  
Total Elongation ◽  
Strength Properties ◽  
Heat Treatments ◽  
Forming Process ◽  
Heat Treated ◽  
Point Bend

To overcome the low room temperature formability of AA7075-T6 aluminum sheet, without sacrificing the high strength properties of this alloy, a hat section beam member was formed and quenched within a cold die immediately after a 20 minute solutionizing treatment. Natural aging for 24 hours followed the forming process which was then followed by various heat treatments that included a typical precipitation hardening (PH) and industrial paint bake (PB) temperature-time treatment. Tensile specimens were extracted from the beams to evaluate their mechanical properties. When compared to the as-received AA7075-T6 mechanical properties, the beams heat treated with the PH, PHPB and PB treatment resulted in a 5%, 13% and 20% reduction in ultimate tensile strength respectively. A similar trend was shown for the yield strength measurements. There was little effect of the heat treatments on the total elongation, with the PH condition showing a slight improvement. A backing plate was riveted to the beams and a quasi-static 3 point bend test was conducted to evaluate the crush performance. The peak load for the PH, PHPB and PB beams was 9.2, 8.5 and 7.3 kN respectively, but the calculated energy-displacement (or energy absorption) curves were similar for the PH and PHPB parts due to a more ductile fracture behavior for the PHPB material condition.

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