Infrastructure Technology Institute
Professor Emeritus Morris E. Fine, an expert in metallurgy and founding member of Northwestern’s Department of Materials Science and Engineering, has been with Northwestern University since 1954. When the department – the first of its kind in the world – was created, he was its first chairman. Precipitation in metals and ceramics has been a principal research area for him since he came to Northwestern. He remains actively engaged in the development and promotion of new, specialized steels, working with ITI and industry partners to advance steel technology. His current work with Research Professor Semyon Vaynman is on the creation of high-performance copper-precipitation-strengthened steel, also known as NUCu Steel (ASTM A-710 Grade B). ITI asked Prof. Fine to share his insights into steel as a primary material for infrastructure.
Steel is an old material. Will it continue to be important in the future?
Steel is here to stay. It’s abundant – 5% of the earth’s crust is iron, and extracting iron from ore is cheap, relatively speaking. Steel is highly recyclable; all steel made today is partially recycled, perhaps 90%. It is a huge class of alloys and can be used in a wide range of applications. It is not going anywhere.
What do think future steels will be like? What can we expect? What are key trends and what is driving them?
I think it will continue to move in the direction of more desirable properties for less cost. Such is the case with what Semyon [Vaynman, Research Professor in the Department of Materials Science and Engineering] and I are working on now – steel with high strength, improved weatherability, improved weldability, and high fracture toughness that is also low-cost. All of these factors are desirable, especially corrosion resistance, and this will drive future developments in steel.
Is there a limit to what we can do with steel properties - strength, toughness, weldability, corrosion resistance?
Sure, there is probably a limit, but we haven’t found it yet. How do you know when you’ve found the limit? Steel has been studied for a long time and there is still much we don’t know about it.
You have the capability to make super high strength steels - 100 ksi steels, but some of our partners are only interested in 50 ksi steels. What is their reasoning?
We have the capability to make much stronger steels than 100 ksi, but it just depends on what market you are targeting. When speaking about building infrastructure, I believe the main factor is still cost. In the automotive industry, they are always interested in very high strength, but in infrastructure there are additional factors to consider – weatherability being key. Our steels have copper added to make them corrosion resistant, but the currently used 50 ksi steel still costs less to produce than our 70 ksi steel. If they are interested in keeping costs down, they will choose the lower strength steel and still have some corrosion resistance. You also have to remember that 50 ksi is still strong compared to earlier steels (normally around 36 ksi) historically used to build bridges.
What does the corrosion resistance of your steel mean for the long-term costs of using this steel for infrastructure?
Because of the increased weatherability of our steel, it does not need to be painted. This provides a significant savings in construction and maintenance costs over the life of a structure.
Is the US steel industry willing and able to make your new steels? Are there obstacles to moving them into the infrastructure market?
Certainly the US steel industry is able to make our ASTM A710 B steel. Five hundred tons were made for the Lake Villa Bridge on Route 83. There is a competing 70 ksi yield strength steel that was developed by the steel industry that has found bridge applications. The manufacturers of the competing steel are not looking for a new steel. There are fixed cost issues. However, one of them did reluctantly make the 500 tons for the Lake Villa Bridge. At this time, several mini-mills would make A710 B or the less expensive, not-as-strong alternative steel if they had an order. Hopefully, the Illinois Department of Transportation will specify the lower-cost alternative for a bridge to be built in Illinois. One heat of steel costs more than $100,000. There has to be a certain application before a steel mill will undertake the expense of making a heat of steel. We have been able to obtain up to 300-pound laboratory-made heats for evaluation.
You have been a professor and now professor emeritus for a long time. What continues to excite you in materials and metallurgy?
Well, what else should I be doing? Being here, I get to talk to interesting people and I get to continue my work. It is better than the alternative.