• Transactions of the Korean Society of Automotive Engineers
• /
• v.20 no.3
• /
• pp.1-6
• /
• 2012

This paper developed the chassis part as micro-alloyed steel with high toughness. The performance of micro-alloy steels are superior to similar heat treated steels. The strengthening effects of vanadium make micro-alloyed steels particularly suited for high-strength-steel applications. The disadvantages are that ductility and toughness are not as good as quenched and tempered (Q&T) steels. Precipitation hardening increases strength but may contribute to brittleness. Toughness can be improved by reducing carbon content and titanium additions. dispersed titanium nitrides (TiN) formed by titanium additions effectively prevents grain coarsening. Grain refinement increases strength but also improves toughness. For the chassis parts using high toughness micro-alloy steel, it had proven superior to a plain steel forging by static strength test and endurance test.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.17 no.3
• /
• pp.141-147
• /
• 2018

Recently, interest in customers has shifted to the emotional quality of customers as the driving, handling, and collision stability of automobiles have been greatly improved. The NVH performance of a vehicle is quantified and evaluated from the DPDS. To improve the DPDS, we need to optimize the shape without considering the increases in thickness of the parts or additions to the parts. And at the same time, we need to establish design and analysis processes to satisfy the requirements of the DPDS.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 2006.06a
• /
• pp.92-92
• /
• 2006

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 2005.05a
• /
• pp.343-343
• /
• 2005

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 2004.05a
• /
• pp.373-376
• /
• 2004

자동차 부품제조에 있어 비용절감과 경량화에 대한 노력은 시간이 지날수록 더욱 그 강도를 더해가고 있다. 이에 따라 tube hydroforming 공법과 고강도 소재를 결합한 부품제조 기술이 국내에서도 활기를 띄기 시작하여 각 자동차사별로 양산 적용을 앞두고 있다. 포스코는 철강소재 자동차 부품 개발에 대한 촉진 및 신수요 창출을 위하여 hydroforming사업을 시작하였으며 이미 수 종의 부품을 국내 자동차사와 공동으로 개발하여 적용을 추진하고 있다. 특히 인장강도 45kg 이상의 고강도 튜브를 이용한 hydroforming샤시 부품을 국내에서 최초로 개발하였으며 현재 시작품 제작을 완료하였다. Hydroforming 부품의 개발은 부품형상 정보를 이용 CAE를 통한 공정해석, 금형의 상세 설계 및 제작 그리고 시작품 제작의 과정을 통해 이루어지며 최종적으로 양산금형이 제작된다. 본 연구에서는 이러한 일련의 과정을 소개하고자 한다.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1995.04b
• /
• pp.510-514
• /
• 1995

설계 초기 단계에서 자동차 샤시 부품의 내구강도를 평가하는 것은 대단히 중요하므로 실제 전산수치해석을 통하여 예측도 행하고 있지만 양산 적용여부는 차량제작 후 실차 내구시험을 시행 후 결정되고 있다. 본 연구에서는 컴퓨터의 잇점을 적극 활용하여, 차량의 주요부품인 Lower Arm과 Rear Axle Housing 등의 내구시험에서 부품의 변형을 탐지하기 위한 자동 측정 프로그램을 개발하고자 한다. 사용한 프로그램은 IBM-PC 호환기종(80286, 80386, 80486)에 사용되는 Turbo-C 언어를, 한글입력을 위해서 한글 라이브러리 <한>을 사용하였다. 그리고사용자가 임의로 시스템 각 요소의 모듈(module)을 대치할 수 있도록 각 함수별로 서브루틴(subroutine)화 하였다.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 2006.05a
• /
• pp.337-340
• /
• 2006

Aluminum extruded profiles have been mostly used only a few automotive parts until now, such as roof rail, sunroof frame and bumper beams. However, Aluminum Extru-form technology, which was recently developed by foreign advanced manufacturer, made it possible to apply the aluminum extruded profiles to suspension parts of passenger and RV cars. It could be obtained by optimized billet casting, extrusion and stretch bending technology. It was possible to have the excellent weight reduction and the competitive price comparing with conventional process of aluminum for automotive parts. Combining additional process technology such as machining and joining, the application can be extended to various automotive parts. We have developed high strength aluminum alloy and fabricated subframe and suspension arm by extruforming process.

• Proceedings of the KWS Conference
• /
• 2009.11a
• /
• pp.83-83
• /
• 2009

The automotive chassis components are structural assemblies that support the engine, suspension, and steering components of the vehicle. For the development of AHSS components, the durability analysis is important. In this paper, the low cycle fatigue property of AHSS was evaluated for the geometry complex and local plasticity in the base material. The GMAW optimization was implemented for the weld soundness using the moving least square method. And the weld S-N curves of AHSS were evaluated to access durability analysis for the weld region. For the verification, the durability analysis of the couple torsion beam axle (CTBA) was performed and compared to the rig test result. The durability analysis using the low cycle fatigue property and the evaluated weld S-N curve of AHSS met the good agreement with the test result.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 2005.10a
• /
• pp.43-45
• /
• 2005

For application of advanced high strength hot-rolled steels (i.e. DP590, DP780) to automotive lightweight chassis parts, various technologies from design to forming test, optimization of welding condition and investigation of coating properties were tried. The target part of this study was automotive rear sub frame and we could make $16.8\%$ weight reduction by reducing the material thickness and optimizing the design. In addition, the formability and weldability of the newly developed AHSS, DP780, were evaluated.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.34 no.10
• /
• pp.1419-1425
• /
• 2010

Boron steel sheet is suitable for fabricating automobile parts because it is very strong and has low weight. Recently, many car makers are investigating the feasibility of fabricating the chassis part of automobiles using boron steel. In order to use boron steel sheets to fabricate the chassis part of automobiles, much better material property of low cycle fatigue life as well as high formability during hot stamping is required. Therefore, the low-cycle fatigue life of hot-stamped quenched boron steel was investigated in this study. The fatigue life observed at low strain amplitude was longer than that of an as-received boron steel sheet. However, the fatigue life reduced at high strain amplitude because of the low ductility and low fracture toughness of martensite, which was produced as a result of hot stamping.