January AMP_Digital

6 A D V A N C E D M A T E R I A L S & P R O C E S S E S | J A N U A R Y 2 0 1 9 USS ARIZONA RESEARCH The Nov/Dec 2018 “Feedback” de- partment included a query from George Vander Voort, FASM, searching for infor- mation on the deck and hull plate steel used on the USS Arizona. Many of you responded and we’ve included a sam- pling of your letters on this page. USEFUL I-T DIAGRAMS International Nickel once pub- lished numerous booklets of both basic and specialized metallurgical interest. One of these is “Isothermal Transfor- mation Diagrams of Nickel Alloy Steels” from 1965. In the mid-1970s, I worked for Simonds Cutting Tools and was in- terested in the hardenability charac- teristics of 2-1/2 nickel saw steel, tra- ditionally used for circular head saws, probably for low temperature tough- ness and good weathering resistance. While that grade was nominally 0.76 nickel, I thought there might be grades described that were similar to the USS Arizona material. In fact, an I-T diagram is published for a nonstandard 3330, conforming to the SAE-AISI nomencla- ture but not commercially important. The nominal composition is C: 0.29; Mn: 0.21; Ni: 3.25; Cr: 1.52. There is no information as to the producer, the forms in which it may have been produced, or the date of development. It’s es- sentially an air-harden- ing grade and might have served as armor plate. Dennis W. Stephens NEW USES FOR NICKEL I worked for Inter- national Nickel Compa- ny from 1965 until 1984. Part of the lore of the company bears on Mr. Vander Voort’s findings. In the early part of the 20th century, armor plate for warships was the major market for nickel. So the ma- terial that Vander Voort found on the Arizona was quite common. With the end of WWI in 1918 and the scrapping of many warships, the market for nickel plummeted. In reaction to this, the In- ternational Nickel Company, then the world’s largest nickel producer, began research programs to find new uses for nickel. The result was many new ap- plications for nickel including electro- forming, copper-nickel alloys, stainless steels, and nickel-base superalloys. John S. Benjamin, FASM RESIDUAL ALUMINUM As a former plate and armor met- allurgist at U.S. Steel’s Research Cen- ter, I might be able to answer some questions. Battleships of that day con- tained various thicknesses of plates; some hull plates were up to 10 inch- es thick, so a high hardenability alloy steel was required. I don’t know which steel company produced the plates for the Arizona, but it was likely either the Homestead Works of U.S. Steel or the Bethlehem Plant of Bethlehem Steel, and yes, made by open hearth practice. I recall one of my predecessors saying that U.S. Steel produced the hull plates of the battleship USS Maine at the turn of the century. That was the ship sunk in Cuba during the Spanish-American War. The Arizona’s 0.32%C-Ni-Cr plate steel was of the “Krupp steel” fami- ly of armor that was common during WWI and was employed in both naval and tank armor. Modifications of that armor are still in use today in both ap- plications, ostensibly with higher Mn, an addition of Mo, and with lower C, P, and S—plus other alloy additions for specific applications. The allegation that the Arizona’s plate steel could not have been deox- idized without Al and with only “resid- ual” Si (0.06% is higher than residual) is suspect. Although, as alleged, no Al was added (intentionally), I believe that the residual Al (perhaps not reported/ recorded) in the steel was likely in the 0.015 to 0.045 range, and that the steel could have contained trace amounts of other deoxidizing residual elements (e.g., Ti, Cb, and Zr). Samuel J. Manganello LOW ALLOY STEELS In the U.S., the only low alloy steels that were standardized with alloy con- tents similar to the deck and hull plates of the USS Arizona were the AISI 93XX series, but they were carburizing grades with much lower carbon contents. It’s been a number of years since I stopped practicing metallurgy and most of my reference material is long gone. Never- theless, my mind tells me that Krupp, in Germany, the huge armaments mak- er in WWI and WWII, favored low alloy steels with compositions similar to the Arizona relics. The reason was that this composition exhibited very high impact strength and was well suited to be used for armor plate and cannon barrels. Irving W. Glater, P.E. FEEDBACK We welcome all comments and suggestions. Send letters to frances.richards@asminternational.org. View of the USS Arizona from the Manhattan Bridge in New York.