a business unit of AISI www.smdisteel.org Steel Intensive Engine Executive Summary 2013
Contributors MAHLE Long Products Market Development Group members: Gerdau Nucor Corporation The Timkin Company
Presentation Summary: Project Purpose The Steel Market Development Institute (SMDI) wanted to conduct a study to define engine performance and weight improvements that may be possible when the engine is designed using an increased number of steel components Project scope Literature survey to quantify current steel usage in engines Review of MAHLE internal reports Brainstorm and information gathering with MAHLE component experts Determination of component weight saving potential Final report MAHLE Powertrain (MPT) to focus on consideration of steel as an enabler Higher strength Smaller package Better heat management Friction Heavy duty engines not widely considered in this study steel content already high MAHLE
Potential Engine Component Evaluation List Component / System Crankshaft Connecting Rods Camshaft Pistons Engine Block Piston Rings Springs Valves Cylinder Liners Ancillary Components Comments Currently cast iron, forged or machined steel. Powder metal FS, steel machined, steel FS. Small volume of Ti. Cast iron or assembled (assumed to be steel). Generally Al for light and medium duty. Stretch goal. Any steel block unlikely to be made using bar stock. Top and oil ring generally steel. Generally all produced from wire. Already steel although produced from wire. Generally already steel. Small volume of Ti. Generally cast iron. Light duty engines tending to parent Al. DI fuel pumps have high-steel content. Brackets will likely be formed from flat sheet if steel. Pumps mix of steel and PM. Turbochargers contain steel shaft. Confidential
Engine Layout Pistons Crankshaft Con Rods Camshaft
Steel Use in Current Engines Comments / Conclusions Results: Expected power-dense engines to use forged rods (Ecoboost) they didn t necessarily Expected higher percentage of powder metal rods in cheaper 4-cylinder engines Surprised by percentage of assembled camshafts in V8 engines Steel use for 4-cylinder crankshafts seems to follow power density and / or bore / stroke ratio Steel cranks used where specific loading is high due to cylinder pressure and / or sectional area smaller bore engines and tightly spaced bores leave less room for additional material Chrysler V6 Pentastar seems to be the odd one out among modern V6 engines by using a cast iron crankshaft (note larger bore and shorter stroke than comparable V6s) V8 / V10 crankshaft material seems to correlate to power density (specific loading) Evidence that manufacturers employ the cheapest solution that will satisfy the requirements 3.5L Ecoboost a good example 1 assembled cam (DI Fuel Pump), 3 chill cast iron cams European engines almost exclusively use forged steel conrods Confidential
Performance-cost Tradeoffs and Potential Range of Technology Options by Vehicle Segment
Market Trends Turbocharging and Downsizing Turbocharging Downsizing Significant growth of gasoline turbo share in Europe NAFTA is following this trend, first with partly importing engines, followed by a growing local production Also increasing gasoline turbo growth in China Japanese OEMs with partly increasing TC share Increasing number of development projects for 2-cyl. engines, 3-cyl. engines also applied in D-segment cars of premium brands (e.g. BMW 3 series) Downsizing in NAFTA on a higher level in, but limited due to higher vehicle mass V8 -> V6, V6 -> I4 Increasing share of 3-cylinder engines in China expected Worldwide Downsizing Scenario* Gasoline Turbo Share* 100% 90% 80% 70% 60% 50% 40% 30% 20% 10% 0% 4,53 315m Cyl. 70m ICE 6.8% 4.1% 2.8% 2.3% 10.7% 8.5% 7.4% 15.2% 72.2% 4,32 315m Cyl. 73m ICE 78.7% 4,14 406m Cyl. 98m ICE 76.6% 4,07 414m Cyl. 102m ICE 76.1% 3,91 392m Cyl. 100m ICE 1.9% 5.4% 71.0% 15.7% 10.1% 11.3% 5.7% 6.0% 0.2% 0.5% 2.0% 2.8% 6.0% 2007 2015 2020 Business as usual 3,60 347m Cyl. 96m ICE 0.9% 2.9% 60.5% 23.0% 12.7% 2020 Hybridization/ Electrifiation >= 8 Cyl. 6 Cyl. 4+5 Cyl. 3 Cyl. <= 2 Cyl. Region 200 9 201 1 201 3 201 5 2017 202 0 Europe 17% 29% 46% 54% 65% 80% Asia 3% 5% 9% 13% 19% 25% NAFTA 2% 6% 12% 19% 27% 35% * by Vehicle Production Region Confidential
Overall Conclusions Engine designers will always favor the lowest-cost solution that satisfies the requirements For steel components to be adopted in larger quantities, they need to act as enablers for something. (I.e. more highly stressed downsized engines) Increasing trend of extreme downsizing lead to higher specific component loading, which is favorable for the steel industry Steel crankshaft distribution unlikely to change in current engine ranges, due to design constraints and cost implications Trend to more extreme levels of downsizing will increase steel crankshaft adoption, due to high specific component loading and desire for compact, lightweight engines Real potential for optimized steel connecting rods offering lightweight, near PM cost with higher strength Confidential
Overall Conclusions Real potential for steel camshafts offering lighter weight, flexibility of individually assembled components and little additional cost technology trends predict significant adoption Real potential for increased volume of steel pistons in the light-duty diesel market with some breakthrough into the highly downsized gasoline market Direct injection engine volume will increase resulting in larger quantity of steel in DI pumps and assembled steel camshafts to drive the pumps Engine downsizing is predicted to be the biggest technology path to achieving lower-fuel consumption. As engines get increasingly downsized, steel content will increase (although physical size will likely decrease) Future engine development to meet legislative targets will dictate the use of alternative materials, including high-strength steel to reduce whole vehicle mass Stretch components, such as cylinder blocks and heads, are unlikely to be manufactured from steel in the future Confidential
Phase II Ideas Original idea take a current engine and analyze weight saving with high-steel content Based on this Phase I study, the potential weight saving of using steel components in an existing engine is likely to be low (and largely based upon camshaft weight saving) Needs complete redesign of engine from clean sheet to optimize for weight Design around tight bore spacing and under square bore / stroke ratio Engine downsizing trend will continue Ever more extreme downsizing with the goal to completely de-throttle the engine for maximum efficiency Will increase loading on components as cylinder pressures increase beyond 140 Bar and Brake Mean Effective Pressure (BMEP) approaches and exceeds 30 Bar Fuel economy benefits will come through engine operating point efficiency gains (de-throttling) and overall vehicle mass reduction Compact, lightweight engines result in lower whole vehicle mass MAHLE
Phase II Ideas New project could look at steel as an enabler for an increasingly extreme downsized engine technology Extreme downsized engine for maximum de-throttling over drive cycle and minimum vehicle mass Look at whole vehicle fuel economy vehicle level drive cycle fuel economy prediction Base next phase project on existing MAHLE DI-3 extreme downsizing engine demonstrator Designed for over 30 Bar BMEP and durable for research and demonstration Currently employs machined steel crank, forged steel rods, steel assembled camshaft Confidential MAHLE
Phase II Ideas Potential scope Finite element analysis of existing components determine maximum specific component loading with acceptable safety factors and ultimate cylinder pressure limit Perform 1-dimensional engine performance simulations to determine new power output Select target vehicle based upon max. safe performance level aim for larger vehicle (I.e. Ford Explorer) 1-dimensional vehicle drive cycle fuel economy analysis with optimized extreme downsized engine and associated de-throttling and mass benefits Confidential MAHLE
For More Information Visit : Contacts: www.autosteel.org Dave Anderson Senior Director 248.945.4764 danderson@steel.org Jennifer Greenfelder Communications Director Automotive Market 248.945.4767 jgreenfelder@steel.org