In 1990s, S&T researchers studied secrets of Titanic steelApril 11, 2012 in Chemistry / Materials Science
Eighty-five years after the RMS Titanic struck an iceberg and sank in the Atlantic Ocean, a faculty member at Missouri University of Science and Technology answered one of maritime sleuths' burning questions about the disaster: Was the steel used to build the ship at fault?
The steel definitely played a role, because it was not as "impact-resistant" as modern steel, said Dr. Phil Leighly, who studied steel from the Titanic in 1996 and 1997. A professor emeritus of metallurgical engineering at Missouri S&T (which was then known as the University of Missouri-Rolla), Leighly said the steel was so brittle that in the chilly waters of the North Atlantic it could shatter easily. But it also was the best steel available at the time, he said.
His research was published in the January 2008 issue of the Journal of Metals.
Now deceased, Leighly spent five months examining samples of the Titanic wreckage. Assisting him was Dr. F. Scott Miller, now an associate teaching professor of materials science and engineering at Missouri S&T. While working on his Ph.D., Miller conducted X-ray microanalysis of the samples of Titanic steel that Leighly had obtained from RMS Titanic Inc., the steward of all artifacts from the luxury ocean liner.
In September 1996, Leighly received three wooden crates containing more than 400 pounds of the three-quarter-inch steel plate of the Titanic's hull. In the months that followed, Leighly, Miller and other S&T researchers tested the material and confirmed that it was inferior to steel used in shipbuilding today. The quality of that steel was a factor in the catastrophe.
Survivors of the Titanic disaster of April 15, 1912, recall hearing loud cracking noises as the ship sank. "When steel breaks," Leighly said, "you expect a groaning, not a cracking sound ... unless the steel is brittle" and therefore prone to fracture.
In the early 1900s, manufacturers in the United Kingdom commonly produced steel in open-hearth furnaces. The process results in "semi-killed" steel, which has relatively high concentrations of phosphorus, oxygen and sulfur, and a low concentration of nitrogen and silicon.
Miller's tests on the Titanic steel back in 1996 and 1997 revealed that the materials matched that semi-killed profile.
The relatively high amounts of phosphorus, oxygen and sulfur in semi-killed steel make it more brittle at low temperatures than modern steel.
"It was bad steel; there's no question," Leighly said, "but probably the best plain carbon ship plate available at the time."
Today, Miller says Leighly's findings should serve as a cautionary tale about the inherent limits of design. The ocean liner's bulkheads were supposed to be watertight, for example, but they weren't.
As Leighly himself said in 1997, "It's easy to point a finger and say, 'Bad steel.' But it's uncomfortable to point at yourself and say, 'Bad design.'"
More than 1,500 of the liner's 2,227 passengers died after the Titanic struck an iceberg in the Atlantic Ocean, some 350 miles off the coast of Newfoundland, Canada. The ship struck the iceberg at 11:40 p.m. April 14, 1912. It sank at 2:20 a.m. April 15.
Provided by Missouri University of Science and Technology
"In 1990s, S&T researchers studied secrets of Titanic steel" April 11, 2012 http://phys.org/news/2012-04-1990s-st-secrets-titanic-steel.html