Viewing 1 to 30 of 259
Technical Paper
Sreedhar Reddy, Vignesh T Shekar
There have always been different approaches when it comes to ‘Bus body architecture’. The design approach has gone through different phases namely, chassis based, semi integral, integral and monocoque. Equally varied is the choice of material for bus super structure. The predominantly used ones are - mild steel with galvanization, stainless steel (SS) and aluminum. This paper discusses the rationale behind choosing stainless steel for the complete bus structure. With rapid development in infrastructure and public mass transit system, it has become imperative to have a robust structure for buses that is durable and crash worthy. Among the family of stainless steels, ferritic stainless steel exhibits excellent mechanical properties with corrosion resistance and better strength to weight ratio compared to the galvanized mild steel.
Technical Paper
Zhigang Wei
Corrosion resistance is an extremely important technical issue for long-term durability and reliability performance of exhaust components and systems. Failure mechanisms, such as corrosion, fatigue, corrosion-fatigue and stress corrosion cracking, have long been recognized as the principal degradation and failure mechanisms of vehicle components and systems under combined mechanical and corrosive environmental conditions. The combination of fluid flow, introduced by components such as advanced injectors, and corrosive environment leads to corrosion-erosion failure mechanism. These failure mechanisms are strongly material, environment, and loading dependent. How to characterize, screen, rank and select the materials in corrosion resistance is a big challenge posed to materials scientists and engineers. In this paper, the common corrosion related failure mechanisms appearing in auto exhaust systems are reviewed first.
Technical Paper
Muthuraj Ramasamy, Vignesh E, Sundararajan Thiyagarajan
Abstract A “WHEEL” is one of those auto component in a vehicle which necessitates equal attention from safety, ergonomics and aesthetic perspectives. A conventional tube type wheel for commercial vehicles is made of steel with steel side rings (multi-piece construction). In course as headway in wheel design the single piece wheels were developed which used the tubeless tires. These wheels were made available in both steel and aluminum versions. Wherein the aluminum wheels were lighter in weight than steel, aesthetically more appealing and had other significant advantages. Despite the advantages of these tubeless tire wheels, the end user had to invest for both wheels and tubeless tires to replace conventional tube type steel wheels. The retro-fitment calls for higher exchange cost of wheel and tire and this process stands to be more capitalistic to the end user wherein the payback period was longer.
Technical Paper
Torbjörn Narström
Abstract The use of modern quenched and tempered steels in dumper bodies to reduce weight to increase the payload and reduce the fuel consumption is briefly discussed. Modern quenched and tempered steels in combination with adopted design concept will further increase weight savings of the dumper body. Use of these materials may lead to 4 times longer wear life than ordinary steels. One of the main load cases for a dumper body is impact of an object, i.e. boulders and rocks, into the body. A well-proven test setup is used to develop a model to predict failure and depth of the dent after the impact. A material model with damage mechanic was utilized to predict fracture. The developed model was used to study the effect of the geometry of the impacting object, thickness of the plate and unconstrained plate field. The model was also implemented in larger model and compared with a full scale test of dumper body.
Technical Paper
Timo Björk, Ilkka Valkonen, Jukka Kömi, Hannu Indren
Abstract The development of weldable high-strength and wear-resistant steels have made modern structures such as booms and mobile equipment possible. These sorts of novel and effective designs could not be constructed with traditional mild steel. Unfortunately, the use of these novel steels requires proper design, and there is no practical design code for these novel steels. This paper addresses stability issues, which are important considerations for designs with high-strength steels, and the properties of the heat-affected zone, which may require special attention. Fatigue design is also discussed in this paper, and the importance of the weld quality is highlighted, along with discussions on which details in the weld are the most important. By comparing the test results with the classical load limit solution, it is determined that full plastic capacity is reached and that the samples display good strain properties.
Technical Paper
Rohitt Ravi, Sivasubramanian, Bade Simhachalam, Dhanooj Balakrishnan, Krishna Srinivas
Abstract Tubular stabilizer bar for commercial vehicle is developed using advanced high strength steel material. Tubular section is proposed to replace the existing solid section. The tubular design is validated by component simulation using ANSYS Software. The tubes are then manufactured of the required size. The bend tool is designed to suit the size of the profile stabilizer bar and the prototypes are made using the tube bending machine. The strength of the tubular stabilizer is increased by using robotic induction hardening system. The tubular stabilizer bar is tested for fatigue load using Instron actuators. Higher weight reduction is achieved by replacing the existing solid stabilizer bar with the tubular stabilizer bar.
Technical Paper
Anjana Deva, S K De, A K Bhakat, B K Jha, S Mallik
Abstract High-strength steels are a cost-efficient means of reducing the weight not only of premium-segment cars but also of light, medium and heavy commercial vehicles. Lighter a vehicle, lower its fuel consumption and the lower its CO2 emissions during driving. Depending on part and use, high-strength steels permit weight savings of up to 30 percent. In this way steel makes a key contribution to sustainable mobility. Innovative high-strength steels allow auto components to be made thinner and thus lighter without sacrificing safety. A wide range of application oriented automotive grades have been developed at SAIL. Despite their high strength, these materials are readily formable and can be processed without difficulty at auto stamping plants. The challenge with these materials is that high strength and good formability are usually mutually exclusive. This conflict is resolved with solutions such as special alloying elements.
Journal Article
Ryoji Suzuki, Yukihide Yokoyama, Takeo Shibano, Tatsuki Sugiura, Noriaki Katori
Abstract 1 One issue raised by the use of austenitic stainless steels in commercial vehicles is the increase in material costs. To reduce those material costs, a nitric acid electropolishing treatment was applied to SUS436L (18 Cr - 1.5 Mo - 0.4 Nb) and corrosion tests were conducted to compare its corrosion resistance to that of SUS316L(16 Cr - 12 Ni - 2 Mo). Compared to SUS316L, SUS436L subjected to nitric acid electropolishing indicated superior corrosion resistance. In addition, XPS and TEM analyses showed that while the SUS436L passivation film layer contained approximately twice as much chromium, its thickness was also generally reduced by approximately half, to 2 nm. These results suggest that electropolishing with nitric acid, which is highly oxidative, formed a fine passivation film.
Technical Paper
V. R. M. Gonçalves, L. C. F. Canale, V. Leskovšek, B. Podgornik
Abstract Spring steels are the materials most commonly used in suspensions of vehicles and are subject to heavy efforts in terms of load, impact and also under intense fatigue solicitation. Required mechanical performance depends mainly on the chemical composition and heat treatments. Therefore, the aim of the present work was to compare SAE 5160 steel with one Super Clean steel developed in Slovenia. Searches improving mechanical properties of these steels are constantly present in the automotive industry, reducing vehicle weight and maintaining safety. In this scenario, cryogenic treatment in combination with quenching and tempering has shown interesting results in the scientific literature for tool steels and the best results for cryogenics are achieved when the treatment occurs for long duration as 24 hours.
Technical Paper
S. Ghosal, B. R. Galgali, M. M. Ogale, S. P. Joshi
The bake hardening effect depends on three parameters i.e. pre-straining, paint baking temperature and paint baking time. The combined effect of all these parameters results into the increase in yield strength, called the “baking effect”. This paper explains the individual effects of these parameters on the baking value. Tensile test were carried out for the 495 samples baked at baking temperature from 140°C to 250°C with differential baking time of 10, 15, 20, 25 and 30 minutes and differential pre-straining of 2%, 3% and 5%. The differences of yield strength between the unbaked and baked sample were calculated and the increase in yield strength was noted. After these laboratory trials 800 numbers of door outer panels of a small truck were formed and finish painted. The increment in yield strength after component forming and painting was determined by taking tensile samples from three different locations of 5 painted doors.
Technical Paper
James Webster
A380 die-cast aluminum engine components are usually joined with steel bolts. Aluminum creep at higher temperatures causes a loss of bolt preload, measured as bolt stretch. A design formula predicting retained bolt stretch is developed based on aluminum creep. This formula correlates well with experimental results for one head gasket and one connecting rod assembly. The formula predicts the effect of joint changes in washers, spacers, bolt size, etc.
Technical Paper
K. Kumarasekaran, Y. B. Safdari
A novel design of an air-gap insulated piston has been proposed which is expected to give a longer life compared to the existing designs. The new composite piston is made of a crown piece which is fitted to the base of a piston through a gasket by an interference fitting and locked by oval shaped rivets radially. A steady state two dimensional thermal analysis is performed on the piston to predict the temperature distribution, then a thermo-elastic analysis is performed to obtain thermal stress distribution. Further, a pure mechanical stress analysis is performed on the piston. These analyses are performed on a Aluminum single piece piston, as reference and an air-gap insulated Ultra High Strength Steel piston using finite element method. Constant temperatures are assumed at gas, liner and oil boundaries of the piston. Also, film coefficients on the piston boundaries are kept constant.
Technical Paper
Charles A. Moyer, Gregory W. Martin
Abstract In order to optimize bearing performance in the 21st Century, bearing life prediction will need to consider bearing ratings (the starting point), the actual environmental conditions in which bearings will operate and will need to identify the appropriate adjustment bridge in order to go from rating life to realistic application life. Generic ratings, as published in Standards, are described in this paper as well as specific ratings for a single type bearing based on explicit, experimentally determined parameters. Life adjustment factors are then discussed covering both the Bearing standards' a1, a2, a3 approach and a more comprehensive life adjustment approach that recognizes the interdependency of the various adjustment factors, subfactors, and the load-life relationship. This concept is demonstrated with tapered roller bearing examples and experimental support for improved bearing life prediction in the more demanding application environments of the future.
Technical Paper
J.K. Spitler
Evolution in the standardization of steel sizes and chemistries has been taking place at Caterpillar over the last eight years. This has occurred through conscious optimization of several internal and external factors. The history, techniques and further potential of the project will be presented.
Technical Paper
W. A. Glaeser
The very fine details of wear scars have been investigated using the Atomic Force Microscope (AFM). The AFM, developed some ten years ago, was designed to image molecules. However, as it has been refined, it has been used in a growing variety of applications. The instrument is essentially a very high resolution profilometer. It uses a stylus with an extremely fine point dragged over a surface. The stylus records minute changes in force as it encounters high points in the surface. It has nanometer level resolution (10-9 meter or 0.04 millionths of an inch). The stylus is rastered over the surface and generates a three dimensional topographic map. A number of different materials, including ceramics, steel and graphite initially subjected to wear, were examined by optical microscopy, scanning electron microscopy and atomic force microscopy. The images were compared. The study showed that each technique reveals unique features.
Technical Paper
Stephen Bond, Darryl Turland
Current trends in environmental and emissions regulations are driving changes in new engine systems, and increasing the need for more effectively sealed joints in exhaust systems. At the high temperatures in these exhaust systems it is difficult for traditional gaskets to provide an effective seal, as they degrade at high operating temperatures. This paper introduces a coating that has both excellent temperature stability and good compliance, thus forming an excellent sealing enhancement for metallic layers in exhaust system gaskets. Temperature stability data is presented along with sealing data, which illustrate the superior performance of this material compared to current systems.
Technical Paper
Fred Specht
Induction heat treating applications for off-highway use are very diverse. The purpose of this paper is to show a variety of applications, machine concepts and close ups of actual heat treating processes. Case depths and hardness requirements vary depending on the end product application. Power requirements usually exceed 100 kW, and the fixtures that position or move the work piece can be quite large and expensive due to the massive part weights.
Technical Paper
Jun Cai, Leo Chuzhoy, Kenneth W. Burris, Douglas A. Rebinsky, Krishna S. Raichur, Patrick H. Campbell
The induction hardening process involves a complex interaction of electromagnetic heating, rapid cooling, metallurgical phase transformations, and mechanical behavior. Many factors including induction coil design, power, frequency, scanning velocity, workpiece geometry, material chemistry, and quench severity determine a process outcome. This paper demonstrates an effective application of a numerical analysis tool for understanding of induction hardening. First, an overview of the Caterpillar induction simulation tool is briefly discussed. Then, several important features of the model development are examined. Finally, two examples illustrating the use of the computer simulation tool for solving induction-hardening problems related to cracking and distortion are presented. These examples demonstrate the tool's ability to simulate changes in process parameters and latitude of modeling steel or cast iron.
Technical Paper
S. M. Gugel
The interest to the new surface heat treatment technologies, which were recently invented in the United States, is constantly increasing in the world industry. Research and developments in the field of Induction Carburizing Technology (LINCARB™), which is the first production technology in large family of new, progressive thermochemical processing (LINTERPROCESS™) are successfully going on. Eleven varieties of this treatment can be used for increasing of machine part resistance against friction and wear, corrosion, fretting, erosion and cavitation by creation of special surface layers. The microstructure and properties of these diffusion coatings can be selected depending on service condition of the part. The protective diffusion coating can be created quickly and economically during seconds or minutes compare to hours and tens of hours which are necessary for traditional methods of treatment.
Technical Paper
Harry W. Walton
A review of many years of published work has shown that hydrogen embrittlement can occur under rolling contact conditions. Breakdown of lubrication and contamination with water have been cited as the probable sources of atomic hydrogen. In this paper, a unique fracture morphology is identified and the mechanism of the fracture progression from initiation to final catastrophic failure is proposed. Development of beneficial residual compressive stress near the contacting surfaces is one approach used to avoid this type of failure. Several alternative methods capable of developing a more desirable stress distribution will be discussed.
Technical Paper
L. C. F. Canale, C. R. Brooks, T. R. Watkins, V. I. Rudnev
Bars of 4140, 1045 and W1 steels have been induction hardened using two different cycles. Prior to hardening, the bars were annealed, developing three different starting microstructures. The microstructures have been characterized by scanning electron microscopy. Microhardness distribution has been measured, and the surface residual stresses have been determined using x-ray diffraction. The results are discussed in the context of the superhardness phenomenon.
Technical Paper
Lin Li, Xiaochun Wu, Luoping Xu
{With the self-restricting test method, heat fatigue behavior of 4Cr5MoSiV1 steel and 8407 steel is investigated under the same heat treatment condition. The crack morphology and fracture surface is also analyzed. Heat fatigue cracks of both steels initiate at the time between 100 to 200 cycles. The initiating cracks of 8407S steel are smaller and more equable than that in 4Cr5MoSiV1 steel. When the annealing temperature is below 610°C, the heat fatigue behavior of 4Cr5MoSiV1 steel is better than that of 8407S steel. However, as the annealing temperature exceeds 610°C, the behavior of the latter seems superior. Also analyzed is the mechanism of heat fatigue, which reveals the main factor affecting heat fatigue resistance is the thermal stability and strength or hardness of steels.}
Technical Paper
Xinmin Luo, Honghong Shao, Huinan Liu
A kind of gas-nitriding process compounding post-polishing and oxidizing was developed. It was revealed that direct quenching could obtain monomorphic dense ε-compound phase. Post-treatment effectively minimized surface porousness and brittleness, brought about fine surface decoration effect, made part's surface static friction factor μ reduce to 0.21∼0.23. No rust spots were found on surface of specimens when sprayed in 5%(wt) sodium chloride solution for 48 hours. Electrode potential value indicated that parts treated possess of better anti-corrosion property than single nitrided. The new process mitigated punch's loading and consumption of dies as well.
Technical Paper
L. C. F. Canale, O. R. Crnkovic, A. F. Farah, C. F. Ferrarini
The present work has the objective to quantify and evaluate abrasive wear resistance of a hard coating. It is obtained by weld deposition of an iron based alloy containing Cr and Nb as carbide forming elements, and to compare it to wear resistance of a heat treated SAE 5160 steel, normally used for agricultural equipment. Wear resistance was determined from two body and a three body abrasion tests using pin abrasion test equipment and a rubber wheel abrasion test, respectively.
Technical Paper
Kathy Hayrynen, Kristin Brandenberg, John R. Keough
The Carbo-Austempering™ process is a high performance steel heat treatment that combines a high carbon bainitic case with either a bainitic or tempered Martensite core to produce a component with an exceptional combination of strength and toughness. This paper will review the Carbo-Austempering™ process and its commercial applications. The properties of Carbo-Austempered™ steel along with the benefits and limitations of the process will also be discussed.
Technical Paper
Anthony C. Y. Lin, Shuenn Chen
Hydroformed truck frame side rails from circular tubes are studied for gage variations and pre-strain to be used in crash FEA modeling practice. This study provides simplified models that achieve feasible correlation with actual tests. Meanwhile, from plasticity theory we derive a forming equation in conjunction with forming limit diagrams to estimate material properties for hydroformed rails.
Shed a few joules with better aerodynamics A team of engineering students from Laval University has managed to reduce the energy demand due to wind resistance of its Supermileage vehicle by 10% after carefully designing a new vehicle body with a 25% larger frontal area. Telemetry helps Formula SAE team close the loop on design Once a year, a team of students at Virginia Tech get to do something that ought to put a grin on any aspiring engineer's face: build a racecar. Unconventional steel wheel designs The drawings done by collegiate students for a steel wheel design competition had industry professionals thinking about future production possibilities.
QT steels make an impact The use of quenchd and tempered steels for dumper bodies reduces weight and fuel consumption while increasing payload capacity and wear life.
Technical Paper
D. P. Cassidy, C. H. Shelton
A low alloy, age hardening nickel-copper-columbium steel has been developed which combines high strength with excellent ductility and adequate toughness for ambient temperature applications. Low carbon content enhances its weldability and a simple heat treatment permits prefabrication of complex structures. These properties permit the designer a wider latitude and provide a basis for economic fabrication and repair of engineered structures.
Technical Paper
E. S. Rowland
Changes in engineering practices, in materials testing, and in techniques, as well as availability of new materials have influenced tangible advances in the tractor industry, according to this paper. The solution of production and technical problems, due in part to expanded investigation and adaptation of developments in other fields, has resulted in superior equipment with greater reliability at lower cost.
Viewing 1 to 30 of 259


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