As many industries push toward production of the lightest (yet strongest) components possible, how do you see steel castings changing over the next 5-10 years? (Voice of the Industry).

"Thin-wall steel castings can, in many cases, be the best casting solution for lightweight, high-performance applications. As component wall thicknesses decrease, the critical property criteria limiting casting designs can be the elastic modulus rather than the yield strength of casting alloys. The elastic modulus of steels is 15-30% higher than that of ductile irons (and austempered ductile irons) and is more that 250% higher than that of aluminum casting alloys. In addition, the high-temperature performance of cast stainless steels points toward the use of thin-wall steel castings for automotive exhaust manifolds.

"Our ability to exploit the opportunities for thin-wall steel castings is limited by the relatively low fluidity of cast steels. However, recent studies have shown that the traditional rule of thumb for using cast steels with wall thicknesses of greater than 6 mm is overly conservative. Conventional gravity-poured steel castings made in shell or nobake molds can be cast readily with 4 mm wall thicknesses. For 3 mm wall thicknesses or less, counter-gravity filling methods or investment casting should be considered to ensure adequate fill. Plain carbon steels also have good mechanical properties in the as-cast condition in thin-wall castings, eliminating the cost of heat treatment."

Bob Voigt, professor, Penn State Univ.

"Uncertainty about performance, the lack of meaningful nondestructive tests and variable casting quality lead equipment designers to cautious component designs when using steel castings. This minimizes the risk of failure, but at a significant performance penalty.

"The use of process modeling combined with meaningful nondestructive tests must be integrated into performance design using computer analysis to reduce weight and increase performance and reliability. Steel foundries will need to take responsibility for the design of their parts. This will allow the foundries to squeeze the highest levels of performance from the lowest weight components."

Raymond Monroe, executive vice president, Steel Founders' Society of America

"The steel casting market has been declining for quite a while. Ductile iron casting, on the other hand, has taken a giant leap in capturing market share away from steel. The challenge here is that in 5-10 years, design engineers are going to demand lighter yet stronger components in steel to exceed the performance of the ductile iron in place now.

"For this to happen, R&D must work:

* to produce thin-wall steel castings and improve as-cast properties;

* to improve steel melting capabilities in induction furnaces rather than arc furnaces (due to cost and environmental standpoints);

* to develop a refractory that keeps melted steel in a controlled atmosphere in the holding furnace, allowing direct pours.

"The thin-wall castings produced with these combined technologies will give the leg up on higher strength, ductility and weldabiliy properties that far exceeds ductile iron capabilities."

Bipin Shah, technical director, Grede Foundries, Inc.

"Since the downturn of the market in the early 80s, it has become harder to stay competitive making steel, castings. Not only has it become a world market, but steel castings face competition from aluminum, iron and plastic. These components weigh less and often cost less. Lighter weight components are attractive, especially as the transportation industry looks to save on fuel costs. Therefore, our industry has to develop a thin-wall casting that is competitive.

"Also, we need to improve processes to create higher quality castings. We need to work towards making castings without defects. We need to embrace technology to become more productive.

"Using technology like robots is advantageous because employees aren't willing to do as much hard labor. Another benefit of robots is that they work without downtime from injury or sickness, They perform the task more consistently and more exactly.

"We currently have three robots in our cleaning and finishing departments. These robots have convinced us that labor-intensive work has higher quality and lower finished casting costs when performed by machines. Higher quality and lower costs, in addition to lighter castings, will help steel foundries stay competitive.

"We are the oldest industry in the world, but we don't need to think like it."

Joe Emmerichs, vice president/general manager, Pacific Steel Casting Co.