Development of Stainless Steel
In the troubled years immediately before World War I, arms manufacturing increased significantly in the UK, but practical problems were encountered due to erosion (excessive wear) of the internal surfaces of gun barrels. Brearley began to research new steels which could better resist the erosion caused by high temperatures (rather than corrosion, as is often mentioned in this regard). He began to examine the addition of chromium to steel, which was known to raise the material’s melting point, as compared to the standard carbon steels.
The research concentrated on quantifying the effects of varying the levels of carbon (C, at concentrations around 0.2 weight %) and chromium (Cr, in the range of 6 to 15 weight %).
In order to undertake metallography to study the microstructure of the experimental alloys (the main factor responsible for a steel's mechanical properties) it was necessary to polish and etch the metallic samples produced. For a carbon steel, a dilute solution of nitric acid in alcohol is sufficient to produce the required etching, but Brearley found that the new chromium steels were very resistant to chemical attack.
It was probably Harry Brearley’s upbringing in Sheffield, a city famous for the manufacture of cutlery since the 16th century, which led him to appreciate the potential of these new steels for applications not only in high temperature service, as originally envisioned, but also in the mass production of food-related applications such as cutlery, saucepans and processing equipment etc. Up to that time carbon steel knives were prone to unhygienic rusting if they were not frequently polished and only expensive sterling silver or EPNS cutlery was generally available to avoid such problems. With this in mind Brearley extended his examinations to include tests with food acids such as vinegar and lemon juice, with very promising results.
Brearley initially called the new alloy "rustless steel"; the more euphonic "stainless steel" was suggested by Ernest Stuart of R.F. Mosley's, a local cutlery manufacturer, and eventually prevailed. It is reported that the first true stainless steel, a 0.24wt% C, 12.8wt% Cr ferrous alloy, was produced by Brearley in an electric furnace on August 13, 1913. He was subsequently awarded the Iron and Steel Institute's Bessemer Gold Medal in 1920.
Virtually all research projects into the further development of stainless steels were interrupted by the 1914-18 War, but efforts were renewed in the 1920s. Brearley had left the Brown Firth Laboratories in 1915, following disagreements regarding patent rights, but the research continued under the direction of his successor, Dr. W. H. Hatfield. It is Hatfield who is credited with the development, in 1924, of a stainless steel which even today is probably the widest-used alloy of this type, the so-called "18/8", which in addition to chromium, includes nickel (Ni) in its composition (18wt% Cr, 8wt% Ni).
After leaving Brown Firth, Brearley joined Brown Bayley's Steel Works, also in Sheffield; he became a director of the firm in 1925.
Read more about this topic: Harry Brearley
Famous quotes containing the words stainless steel, development of, development, stainless and/or steel:
“I stir my martinis with the screw,
four-inch and stainless steel,
and think of my hip where it lay
for four years like a darkness.”
—Anne Sexton (1928–1974)
“Women, because of their colonial relationship to men, have to fight for their own independence. This fight for our own independence will lead to the growth and development of the revolutionary movement in this country. Only the independent woman can be truly effective in the larger revolutionary struggle.”
—Women’s Liberation Workshop, Students for a Democratic Society, Radical political/social activist organization. “Liberation of Women,” in New Left Notes (July 10, 1967)
“Creativity seems to emerge from multiple experiences, coupled with a well-supported development of personal resources, including a sense of freedom to venture beyond the known.”
—Loris Malaguzzi (20th century)
“The American people is out to get the kaiser. We are bending every nerve and every energy towards that end; anybody who gets in the way of the great machine the energy and devotion of a hundred million patriots is building towards the stainless purpose of saving civilization from the Huns will be mashed like a fly. I’m surprised that a collegebred man like you hasn’t more sense. Don’t monkey with the buzzsaw.”
—John Dos Passos (1896–1970)
“The complaint ... about modern steel furniture, modern glass houses, modern red bars and modern streamlined trains and cars is that all these objets modernes, while adequate and amusing in themselves, tend to make the people who use them look dated. It is an honest criticism. The human race has done nothing much about changing its own appearance to conform to the form and texture of its appurtenances.”
—E.B. (Elwyn Brooks)