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2013-09-24
Technical Paper
2013-01-2419
Jeffrey Nichols
The focus of Cost Competitive Light-weight materials is a significant and relative objective for Commercial Vehicle Manufacturers and Component Suppliers. The continued development of ultra-high strength materials to offer improved strength, durability, and mass reduction with a cost competitive position, is a primary emphasis within engineering activities globally. This cost competitive light weighting focus has expanded significantly in all areas of commercial vehicle segments, impacting both powertrain and chassis applications. The focus is largely driven from the direct correlation of reduced vehicle mass to improved vehicle fuel efficiency, Co2 and Nox reduction, as well as safety and overall improvements to durability and performance. The primary challenge to determine the optimal lightweight material is multifaceted in effort to meet all imperative load criteria, while simultaneously providing mass savings in a globally scalable cost competitive solution.
2013-09-24
Technical Paper
2013-01-2418
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.
2013-09-24
Technical Paper
2013-01-2420
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.
2011-09-13
Journal Article
2011-01-2306
Xin Lei, Antoun Calash, John Cagney
A cyclically pressurized hydraulic component made of compacted graphite iron (CGI) is examined in fatigue design. This CGI component has a notch, formed at the intersection of two drilling channels. This notch causes the stress to be locally elevated and may potentially serve as a fatigue initiation site. Traditional fatigue design approaches calculate the maximum stress/strain range acting at the notch and apply the Neuber correction when calculating fatigue life. It is, however, found that the fatigue life is dramatically underestimated by this method. This prompts the use of the critical distance method because the stresses are concentrated in a relatively small volume. When using the critical distance method, the fatigue life is correctly predicted. Finally, a fracture mechanics model of the crack check the reasonableness of the critical distance method results.
2011-10-04
Technical Paper
2011-36-0298
Edney Rejowski, Edmo Soares, Samantha Uehara
The demand for higher output performance engines has lead to the increase of PCP (Peak Cylinder Pressure) and more aggressive engine designs for cylinder liners, mainly for new heavy duty engines developments where low cost components are been introduced. Such trends have generated demands to adequate the liner design by improving its material properties by changing its chemical composition, new materials data or even by introducing more accurate casting manufacturing process. Therefore, there is a clear tendency to development more and more alternative solutions that combine a certain technical high-value added and low cost. The most important material properties for cylinder liners are the ultimate tensile strength (UTS) and the fatigue tensile strength. Both parameters confer to the cylinder liners, especially for wet top flanged designs, the ability to survive under high mechanical and thermal load conditions even with reduced wall thickness.
2015-01-14
Technical Paper
2015-26-0068
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.
2014-05-07
Technical Paper
2014-36-0008
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.
2014-05-07
Technical Paper
2014-36-0031
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.
2014-04-28
Technical Paper
2014-28-0006
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.
2014-04-28
Technical Paper
2014-28-0007
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.
2016-04-05
Journal Article
2016-01-0354
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.
2016-05-11
Technical Paper
2016-36-0064
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.
2008-10-07
Technical Paper
2008-01-2684
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.
1992-04-01
Technical Paper
920925
Ron Jones
Hydraulic operating pressures on offhighway vehicles have increased steadily over the years. Depending on the function, the majority of the systems now operate between 2250 psi and 3500 psi. External gear pumps have provided the reliability and performance required for most of these applications and with improvements in gear pump technology, they will keep pace with the higher pressure requirements of the earthmoving industry. This paper addresses the development of gear pumps that will meet the future demands of vehicle designers for pumps rated at 4500 psi.
1994-09-01
Technical Paper
941738
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.
1994-04-01
Technical Paper
941069
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.
1991-09-01
Technical Paper
911797
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.
1991-04-01
Technical Paper
910953
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.
1996-08-01
Technical Paper
961815
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.
1996-08-01
Technical Paper
961819
Edward R. Eaton, Sam Alexander
Abstract: This paper reports how, as part of a continuous quality improvement program, a major high output (over 1000 KW) engine OEM and its coolant technology supplier identified specific opportunities for improving the coolant chemistry used in the subject engines. Specific objectives included: optimize the stability of the coolant chemistry as evidenced by the reduction or elimination of radiator tube plugging; reduce the need for cooling system cleaning and maintenance; extend the life of the coolant to coincide with the time period between engine overhauls; Improve maintenance simplicity and tolerance for errant maintenance practices. The existing coolant program, derived from successful highway engine service practices, was reviewed and the chemistry of the supplemental coolant additive (SCA) was modified to more precisely address the characteristics of the subject engines. In particular, the SCA was reformulated without silicate, since the subject engines contained no aluminum.
2003-11-10
Technical Paper
2003-01-3403
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.
2002-03-19
Technical Paper
2002-01-1558
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.
2002-03-19
Technical Paper
2002-01-1557
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.
2002-03-19
Technical Paper
2002-01-1451
Robert F. O'Rourke
Cast iron is generally thought of as a weak, dirty, cheap, brittle material that does not have a place in applications requiring high strength and defined engineering properties. While gray cast iron is relatively brittle by comparison with steel, ductile iron is not. In fact, ductile iron has strengths and toughness very similar to steel and the machinability advantages make an attractive opportunity for significant cost reductions. Gray and ductile iron bar stock is commercially available and can be used as a direct replacement in applications that are currently being made from carbon steel bar. Ductile iron bar stock conversions are very prevalent in many fluid power applications including glands and rod guides, cylinders, hydrostatic transmission barrels and in high-pressure manifolds. Automotive gears are being converted to ductile iron for its damping capacity and cost reductions.
2002-03-19
Technical Paper
2002-01-1442
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.
2002-03-19
Technical Paper
2002-01-1412
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.
2002-03-19
Technical Paper
2002-01-1411
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.
2002-03-19
Technical Paper
2002-01-1410
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.}
2002-03-19
Technical Paper
2002-01-1368
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.
2002-03-19
Technical Paper
2002-01-1390
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.
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