Harry Brearley

Harry Brearley (February 18th 1871 in the Sheffield - August 12th 1948 with Torquay) was a Métallurgiste English. One owes him the invention in 1913 of the rustless steel (“steel without rust”) which will be later renamed Stainless steel.

Biography

Harry Brearley knew modest beginnings like wire of founder. It gave up the school with 12 years to become workman in one of the steel-works of Sheffield before being transferred to the station from general assistant in the chemical laboratory from the company.

During several years, in addition to its work at the laboratory, he studied at his place and specialized later while following courses of the evening in techniques of production of chemical steel and of methods of analysis.

At the beginning of about thirty, it had acquired a reputation of experienced professional whom can develop astute solutions with the problems of industrial metallurgy application. In 1908, two companies of iron and steel industry of Sheffield decided on a partnership to finance a project of laboratory (Brown Firth Laboratories) and Harry Brearley was selected to direct the project. While studying how to solve the problems of erosion of the barrels of firearm, it developed a formula steel iron/chromium which it baptized ruthless steel (“steel without rust”) which will be later renamed “stainless steel” ( stainless steel ) by Ernest Stuart, a cutler of the city. The first cast one would have taken place the August 13rd 1913 and this innovation was worth to him to receive in 1920 the gold medal of the Bessemer Institute for iron and steel.

Harry Brearley died in 1948 in Torquay, a seaside resort of the South of England.

Development of the stainless steel

In the years preceding the First World War, the manufacture of weapons increased exponentially in England, but one butted against problems of erosion inside the guns of the firearms. Brearley started to seek new alloys more resistant to erosion at high temperature (and not with corrosion as one would be in right to think). He studied the addition of chromium to the steel, which one knew at the time he would increase the melting point compared to a carbon steel traditional.

He concentrated mainly his research on the quantification of the effects of the variation of the carbon rate (around 0,2 % in mass) and of chromium (between 6 and 15 %).

In order to study the microstructure of these experimental alloys, which is the independent factor influencing the mechanical properties, it is necessary to polish and attack with the acid the samples. For a carbon steel, a simple nitric solution of Acid diluted in the ethanol is enough to obtain the chemical attack desired, but Brearley realized that the new chrome steels were very resistant to the acid attack.

Harry Brearley included/understood the potential of these new steels, not only for the wear resistance at high temperature of the firearms, like initially envisaged, but also for the production of kitchen utensils: cutlery, pans, etc Sheffield were indeed a city considered for the manufacture of knives since the 16th century. With these applications to the spirit, it tried out on its steels the attacks of food acids like the vinegar and the juice of lemon and obtained very promising results. At the time, carbon steels were unsuitable with a food use if they were not regularly polished because of their tendency to corrode. Only expensive covers in Money sterling (standard silver 925) or in Copper nickel zinc alloy, made it possible to avoid this kind of problems.

Brearley baptized these steels rustless steel , which was renamed stainless steal (litt. “steel without task”, or “pure steel”, the English current name of the stainless steels) by Ernest Stuart, a local cutler who worked for RF Moseley' S.

The first “stainless steel” was a ferrous alloy containing 0,24 % in carbon mass and 12,8 % of chromium. The first cast one took place in an electric furnace, the August 13rd 1913.

At the time of the First World War, any project on the stainless steel was stopped. In the Années 1920 research showed in spite of the departure of Brearley of Brown Firth Laboratories in 1915 following an argument concerning its rights in the patents. Its successor, W.H. Hatfield took again research and developed in 1924 steel “18/8” (18 % in chromium mass and 8 % out of nickel) which is probably the representative more used stainless steels iron/chromium.

See too

History of the techniques

Random links: