Your Selections

Park, Hyounsoo
Show Only

Collections

File Formats

Content Types

Dates

Sectors

Topics

Authors

Publishers

Affiliations

Events

   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Study on Application Methods to Mitigate Galvanic Corrosion between Wheel Bearing and Aluminum Knuckle

Iljin Global-Sewoong Kim, Seonho Lee, Hyounsoo Park
Published 2019-09-15 by SAE International in United States
The substitution of aluminum for steel is an effective weight reduction solution where the application permits it; aluminum knuckles have been widely used for this reason. However, when an aluminum knuckle is assembled with the steel outer-ring of a wheel bearing without any means for galvanic corrosion prevention, the aluminum knuckle may severely corrode. Galvanic corrosion products can make it difficult to remove a wheel bearing from the aluminum knuckle during vehicle maintenance. Prevention of this problem is the focus of this paper. In this study, several concepts were examined to prevent or mitigate galvanic corrosion between a wheel bearing and its mating aluminum knuckle. One set of concepts involves using surface treated metal sleeves (using ferritic nitro-carburizing or a special coating). The sleeves were then inserted onto the outer-ring diameters of the wheel bearings prior to assembly into the steering knuckle. Another set of concepts that were investigated involves the application of thin coatings having high anti-corrosion properties. The coatings were applied directly to the bearing outer-ring knuckle piloting surfaces and bearing knuckle mounting…
This content contains downloadable datasets
Annotation ability available
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Metallurgical Approach for Improving Life and Brinell Resistance in Wheel Hub Units

SAE International Journal of Materials and Manufacturing

ILJIN Group-Seonho Lee, Yoongil Choi, Kyuntaek Cho, Hyounsoo Park
  • Journal Article
  • 05-11-01-0008
Published 2017-09-17 by SAE International in United States
Raceway Brinell damage is one major cause of wheel bearing (hub unit) noise during driving. Original Equipment Manufacturer (OEM) customers have asked continuously for its improvement to the wheel bearing supply base. Generally, raceway Brinelling in a wheel hub unit is a consequence of metallic yielding from high external loading in a severe environment usually involving a side impact to the wheel and tire. Thus, increasing the yielding strength of steel can lead to higher resistance to Brinell damage. Both the outer ring and hub based on Generation 3 (Gen. 3) wheel unit are typically manufactured using by AISI 1055 bearing quality steel (BQS); these components undergo controlled cooling to establish the core properties then case hardening via induction hardening (IH). This paper presents a modified grade of steel and its IH design that targets longer life and improves Brinell resistance developed by ILJIN AMRC (Advanced Materials Research Center). And also, this focuses on demonstrating the improved Brinell resistance using exclusive Brinelling test. The strengthening mechanism is the fine grains generated by restriction of grain…
This content contains downloadable datasets
Annotation ability available
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Fatigue Strength and Residual Stress Analysis of Deep Rolled Crankshafts

Advanced Technology Center, Hyundai Motor Company-Young Sang Ko, Jeen Woo Park, Hyoung Oh Bhan, Hyounsoo Park, Jong Dae Lim
Published 2005-04-11 by SAE International in United States
The endurance life of an engine crankshaft is closely related to its fatigue strength, in addition to other material properties and shape parameters. Deep rolling, moreover, enhances the fatigue limit by applying compressive residual stress within the fillet radius area as a major surface hardening technique. The objective of this research is to maximize engine fatigue life through crankshaft design optimization by quantifying fatigue strength for microalloyed steels versus a Cr-Mo alloy steel, and to examine the effects of deep rolling load and rolled fillet geometry.Fatigue tests have been made with standard rotary bending test samples from both bar and forged blanks. Rig tests for actual crankshafts have been made to show how the fatigue strength correlates with different sample types. A correlation of stress distribution with bending moment was demonstrated by applying a strain gauging technique on crankshaft specimens. Therefore, an analysis of combined stresses could be made by considering the effect of static residual stress in addition to the applied dynamic bending stress.A correlation of rolling load, surface hardness as well as residual…
Annotation ability available
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Application of 3d Hot Forging Process Simulation for V6 Engine Crankshaft

Hyundai Motor Co.-Young Sang Ko, Hyounsoo Park, Seung Cheal Jung, Jong Dae Lim
  • Technical Paper
  • 2003-08-0009
Published 2003-05-21 by Society of Automotive Engineers of Japan in Japan
Newly developed 3D forging process simulation has been introduced to optimize the process control of automotive forging parts. We analyzed forgeability of steels at various operating parameters such as forge load, temperature and die shape. The simulation data are also correlated to the experimental results of thermomechanical characteristics.The correlation of manufacturing variables and microstructures of forged V6 engine crankshaft has been evaluated by using thermomechanical simulator. The FEM simulation of virtual forging is in good agreement with real forged parts, and consequently, we could quantify the forging process and predict the material properties.
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Development of Fracture Split Steel Connecting Rods

Hyundai Motor Company, R&D Center-Hyounsoo Park, Young Sang Ko, Seung Cheal Jung, Byung Tag Song, Yong Ha Jun, Byung Cheol Lee, Jong Dae Lim
Published 2003-03-03 by SAE International in United States
Fracture split steel connecting rod has been developed for new passenger diesel engines for its advantages in cost saving and better performance. The splitting type of steel con rod is made of high carbon micro-alloyed steel with no additional heat treatment after hot forging. This con rod blank is forged in one-die mold and later fracture splitted. Unlike the conventional types where the rods and caps are separately forged and machined, this steel split con rod needs no additional rod/cap contact face milling which means a substantial savings in machining cost. Besides, a firm contact between rod and cap improves stiffness and compatibility with other crank-train moving parts - a definite merit in engine performance.Our research work focuses on optimizing the two major technologies in this subject - microstructural analysis of controlled cooling (high carbon micro-alloyed steels) and detailed fracture splitting parameters and test results. We are now expecting up to a 25% reduction in cost as well as a significant improvement in engine performance (stiffness increase of at least 10%, weight tolerance of forge…
Annotation ability available
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Fatigue Life Analysis of Crankshaft at Various Surface Treatments

Hyundai Motor Company, R&D Center-Hyounsoo Park, Young Sang Ko, Seung Cheal Jung
Published 2001-10-01 by SAE International in United States
The service life of engine crankshaft is closely related to its material characteristics. Without any dimensional modification, one can significantly improve the fatigue life of crankshaft by applying various surface treatments. The objective of this research is to predict and to quantify the fatigue life of crankshaft at different alloy design and surface treatments - microalloyed steel vs. carbon steel as well as nitriding vs. fillet rolling. It is found that nitriding improves more than 60% in fatigue life depends upon matrix hardness. This study also demonstrates a relationship between fatigue life and fillet rolling force. We observed that the fillet rolled specimens with the applied force of 500∼900kgf exhibit 40∼80% improvement in fatigue life compared to non-treated sample. Consequently, methods are proposed to quantify and normalize fatigue life at various treatments to optimize crankshaft design for maximizing the engine performance.
Annotation ability available
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Development of Special Heat Treatment to Improve the Bearing Fatigue Life

Hyundai Motor Company-Hyounsoo Park, Seung Cheal Jung, Tae Won Lim
Published 1999-03-01 by SAE International in United States
A new technique of heat treatment is developed for the bearings of automotive transmission and chassis to maximize their service life under contaminated and severe environments. This study demonstrates an improvement of the microstructure of bearing steels by applying special heat treatments. The microstructure is developed by optimizing various heat treating parameters (temperature, cycle time and gas atmosphere, etc.) as well as by modifying the quenching processes (double quenching and press quenching). We obtained a desirable microstructure of dense and fine martensite with optimum levels of retained austenite and compressive residual stress on the subsurface. The size and distribution of carbides and grains are found to be very fine and homogeneous. The endurance test results show that the specimens with new treatment have an excellent fatigue life compared with the conventional bearing samples.
Annotation ability available