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An innovative seat back design for fold down split-rear seat backs has been developed for application in SUV’s, MPV’s and hatchbacks. The all-thermoplastic seat back design meets US and European government regulations such as, the FMVSS 210, 207 in the US, and ECE 17 (luggage retention) in Europe. It is also expected to meet the newly introduced FMVSS 225 (child seat belt tether load) requirement. Currently application of the blow molded seat back is limited to sedans where the seat belt anchor loads are transmitted to a steel package shelf. For applications where the seat-belt anchor loads are transmitted to the seat back, hefty steel frame and reinforcements are required which add weight and cost to the seat back. The same is true for seats that need to comply with the European luggage retention requirement.

The Auto/Steel Partnership established the Light Truck Frame Project Group in 1996 with two objectives: (a) to develop materials, design and fabrication knowledge that would enable the frames on North American OEM (original equipment manufacturer) light trucks to be reduced in weight, and (b) to improve corrosion resistance of frames on these vehicles, thereby allowing a reduction in the thickness of the components and a reduction in frame weight. To address the issues relating to corrosion, a subgroup of the Light Truck Frame Project Group was formed. The group comprised representatives from the North American automotive companies, test laboratories, frame manufacturers, and steel producers. As part of a comprehensive test program, the Corrosion Subgroup has completed tests on frame coatings. Using coated panels of a low carbon hot rolled and pickled steel sheet and two types of accelerated cyclic corrosion tests, seven frame coatings were tested for corrosion performance.

Usinor has developed organic and inorganic films, for many automotive applications. The surface post-treatments made by the coil-coater provide additional functions to the metallic coated steel, such as lubrication or corrosion protection, and offer an excellent compromise between car manufacturing, steel utilisation and costs saving. Even though the organic coating thickness can reach 8 μm, steel products can be welded and electro-painted, thanks to metallic pigments within the coating, which make the polymer conductive. In some particular cases, where high flexibility and formability are required, the best solution is organic non-pigmented systems with lower thickness from 1 to 2 μm. Other pre-painted steel systems with thicker organic coatings have the potential to replace ED-paint or to remove Primer-Surfacer on paint lines by the car manufacturer.

Connecting rods manufactured by the Precision Powder Forged (P/F) process offer several distinct advantages over those produced by all other methods including the state-of-the-art forged steel process. Precision P/F connecting rods have mechanical properties equivalent to those made from forged steel, with the added benefits of greater design flexibility, superior dimensional and weight precision, simplified finish machining and assembly, better machinability, and increased consistency because of highly stable metallurgy and a robust and reliable manufacturing process. The inherent flexibility of the P/F process also facilitates tailoring materials to achieve the optimal balance of strength and machinability for a given application. In combination, these advantages result in a product that requires less capital investment for finish machining, is more environmentally conscious by generating substantially less waste, exhibits better total performance, and has lower total cost.

Automotive engineers are challenged with increasing fuel economy in transportation vehicles by reducing weight. Aluminum castings are replacing cast iron components as one way to reduce weight in cars. Many of the aluminum castings produced for automobiles today are made with a sand core to form the internal cavity of the automotive component. Currently, the most popular choice of sand binder system in core making is the phenolic urethane cold-box binder system. This system, however, was not designed for use at aluminum pouring temperatures. The collapsibility of a phenolic urethane cold-box core is not sufficient for expedient shakeout in an aluminum casting. Because of this, many aluminum castings must undergo secondary core removal processes. This reduced shakeout effectiveness limits the designer in the casting geometries available and adds cost to the part.

The use of cutting fluid in machining operations not only poses a health risk to workers but also creates environmental challenges associated with fluid treatment and disposal. In an effort to minimize these concerns and eliminate the costs associated with cutting fluids, e.g., purchase, maintenance, and treatment, dry machining is increasingly being considered as an alternative. This paper is focused on comparing dry and wet machining approaches from several perspectives, including air quality, product quality, and economics. Both experimental and analytical work is presented. Experiments have been performed to determine the effect cutting fluid has on product quality and aerosol generation in the wet and dry turning of gray cast iron. To compare costs in wet and dry turning, a cost model, which includes cutting fluid-related components, has also been established.

Malleable and ductile cast irons are used extensively in automotive applications such as clutches, gears, carriers, shafts, bearings, cam, racers, hubs, etc. Recently developed P/M materials can be processed cost efficiently to replace malleable and ductile iron castings. An UTS in excess of 1240 MPa and a YS in excess of 825 MPa can be achieved with one of these new materials. These tensile properties can be coupled with elongations over 2% and impact energies over 25 Joules. This presentation will cover processing routes for these new materials and will identify parts that may benefit from this new technological advancement.

Advanced powder metal technology is capable of producing carburized, low alloy steel bearings and gears that deliver mechanical performance comparable to conventional steel. This quantum leap in PM technology has been accomplished by applying cold work densification to surfaces that require enhanced durability in the application. Using various test methods, core and surface properties are compared for the PM and conventional steel materials; namely tensile, impact toughness, bending fatigue, and contact fatigue. A back to back durability test for automotive manual transmission gears has been used to compare PM gears with conventional steel gears. Test data shows that PM gear teeth can endure equivalent contact stress and, by employing design benefits which are exclusive to PM tooling related gear tooth manufacture, similar tooth loading as conventional gears. PM manufacturing can achieve AGMA 10 gear quality.

The importance of powder technology to the automotive industry is well known, mainly due to its growing potential. This work presents aspects related to high-speed steels for valve seat inserts application. Four series of materials were evaluated: high speed steel M3/2 infiltrated with copper during sintering; high speed steel M3/2 with Cu3P addition; high speed steel M3/2 with Cu3P addition and further copper infiltrated during sintering; high speed steel M3/2 mixed with iron powder. The main material selection topics such as cost, performance, reliability, and environmental aspects were considered. The physical and mechanical properties of the evaluated high-speed steels are presented in terms of densification, hardness, and radial mechanical strength.

The demands on valve seat inserts are that they should have enhanced wear resistance and machinability using non-environmentally hazardous materials at a reasonably low cost. Research into the possibility of producing a new valve seat insert material which fulfills such demands was therefore made. As a result Hitachi Powdered Metals (HPM) has developed a new material which uses dispersed die steel hard particles in the production of intake valve seat inserts.

The influence of graphite shape, pearlite content and chemical composition have been investigated to determine their effect on the machinability of compacted graphite iron (CGI). In the comparison to gray iron, the reduced sulfur content of CGI prevents the beneficial formation of a protective manganese sulfide layer on the cutting insert. This accounts for much of the difference in tool life during high speed continuous cutting. Beyond this critical mechanism, the machinability of CGI can be optimized by providing a consistent, low nodularity microstructure with a minimum of tramp elements such as titanium and chromium that form abrasive inclusions.

The last ten years has seen the North American automotive industry increasing its use of magnesium castings at an annual rate of around 15% and this rate of growth is expected to continue for at least the next ten years. The main driving force for this increasing use of magnesium is the need to reduce vehicle weight and improve fuel economy. Magnesium alloys are amongst the lightest structural materials available, however, they do cost more per unit mass than competing materials such as steel and aluminum and the automotive industry is reluctant to pay a premium for weight saving. However, in spite of an apparent cost penalty, magnesium castings are currently used in a number of automotive body, chassis and powertrain applications and this paper will review these applications. There is also a significant potential for future growth in the use of magnesium casting by the automotive industry where there may be little or no cost penalty.

A multiaxial spot weld damage parameter and a basic load-life approach are applied to proportional shear and peel loading for a standard SAE variable amplitude loading history. Miner's rule and the rainflow cycle counting method are used to calculate fatigue damage using constant amplitude load-life test data for various ratios of the combined loading. The calculations are compared to test results for an HSLA galv-annealed sheet steel obtained by using the DaimlerChrysler Spot Weld Design Committee multiaxial spot weld test fixture. The applicability of the methods are discussed, as are the crack initiation and propagation behavior of the specimens.

This paper presents the progress of an ongoing vehicle micro corrosion environment study. The goal of the study is to develop an improved method for estimating vehicle corrosion based on the Total Vehicle Accelerated Corrosion Test at the Arizona Proving Ground (APG). Although the APG test greatly accelerates vehicle corrosion compared to the field, the “acceleration factor” varies considerably from site-to-site around the vehicle. This method accounts for the difference in corrosivity of various local corrosion environments from site-to-site at APG and in the field. Correlations of vehicle microenvironments with the macroenvironment (weather) and the occurrence of various environmental conditions at microenvironments are essential to the study. A comparison of results from APG versus field measurements generated using a cold rolled steel based corrosion sensor is presented.

For auto-body structures, thin walled hydroformed and laser beam welded hollow steel sheet sections are recommended as a replacement for mainly spot-welded box-shape components. Such components have the same strength but a lighter weight. Pre-bending into the required shape prior to the hydroforming step is difficult to realize in the case of thin wall thicknesses in combination with small bending diameters and relatively large tube diameters. There are bending limits with respect to buckling or cracking which have still to be clearly defined. The boundaries for the cold rotary draw bending process are fixed in the so called “bending diagram”. This diagram in itself is insufficient. Based on simple equations in combination with numerical calculations, an analytical equation was drawn up to better define the boundary conditions. This also takes into account the influence of the material.

Automotive exhaust gas condensate causes severe corrosion inside mufflers. Corrosive condensate became a problem following the introduction of three-way catalytic converters in exhaust systems. The authors previously established a new laboratory test method that simulates condensate corrosion. This test method contributed to the development of new stainless steels for automotive mufflers. The addition of molybdenum (Mo) and copper (Cu) to ferritic stainless steels was found to be effective in improving condensate corrosion resistance, and the effect was arranged using the index [%chromium (Cr)+3×%Mo+1.5×%Cu]. A field test was carried out to investigate the corrosion behavior of mufflers under actual conditions. Aluminized steels showed severe damage by general corrosion. On the other hand, 19%Cr-Cu ferritic stainless steel exhibited excellent corrosion resistance. The corrosion behavior in the field test showed good agreement with the results of the laboratory test.

A method of cleaning lubricating oil on line was investigated using a fine bypass particulate filter followed by an infra red heater. Two bypass filter sizes of 6 and 1 micron were investigated, both filter sizes were effective but the one micron filter had the greatest benefit. This was tested on two nominally identical EURO 1 emissions compliance refuse trucks, fitted with Perkins Phazer 210Ti 6 litre turbocharged intercooled engines and coded as RT320 and RT321. These vehicles had lubricating oil deterioration and emissions characteristics that were significantly different, in spite of their similar age and total mileage. RT321 showed an apparent heavier black smoke than RT320. Comparison was made with the oil quality and fuel and lubricating oil consumption on the same vehicles and engines with and without the on-line bypass oil recycler. Engine oils were sampled and analysed about every 400 miles. Both vehicles started the test with an oil drain and fresh lubricating oil.

Kühl Wheels utilize a system of offset, sheet steel spokes to form the structure between hub and rim. This allows a wheel with adequate strength to sustain radial, cornering and torque loads while providing weight as well as styling advantages. Initial development of welded prototype wheels is described, including laboratory and field test results. The development of a single piece, steel, stamped wheel center based on the early prototypes is described. Critical aspects of the design are shown and geometric requirements are discussed. Wheel model analyses carried out by finite element methods are presented. Development of tooling and ultimately stamped prototypes is discussed and shown. Finally, test results from wheels assembled from the stamped wheel centers are presented and compared with the analytical predictions.

In automated machining processes, long and continuous chips often cause machine down and hence increase process cost. Chip control or chip breaking methods are essential for unattended and automated systems such as CNC metal cutting machine or other fully automated metal cutting machines, especially for those which are integrated into production line. Conventional metal cutting chip control relies on the knowledge of chip flow angle, chip curl and breakage. In this paper, a new concept of metal cutting chip breaking using laser energy is presented and discussed. Preliminary laser chip breaking for copper, aluminum and steel was investigated under static conditions by using a commercially available pulsed Nd:YAG laser. The results showed that the effectiveness of chip breaking by lasers varied dramatically at different levels of laser energy with or without assisted blow-off air.

The automotive industry is exhibiting the trend of positively adopting stainless steel pipe as one of the means for improving weight reduction and rust resistance. In particular, austenite stainless steel pipe (hereafter referred to as “SUS pipe”) is widely used in automotive parts due to its excellent rust resistance, heat resistance, and magnetic properties. Nevertheless, reports regarding the forming technology of SUS pipe are rare. In particular, reports on the thin-sheet SUS pipe, which this paper discusses, are extremely rare. Up until now, the application of SUS pipe for various parts consisted primarily of 1.0mm-thick materials. The thin-sheet SUS pipe material is known to be difficult to shape because of its low sheet rigidity relative to the forming force, resulting in wrinkles and buckling. Moreover, it is susceptible to galling in the die due to the hardness of the material, making it also difficult to shape.