STAINLESS STEEL

Evening Star, Issue 20585, 10 September 1930, Page 11

STAINLESS STEEL

AH ACCIDENTAL DISCOVERY The discovery of stainless steel may bo said to have been almost accidental (writes Einbrey Crawford, in the Melbourne ‘Argus’). A young chemical analyst and metallurgist, Harold Brearley, visited a small arms factory in England in .1912. The barrels of rifles in those days wore out, in., such a short time that many metallurgists had been giving their attention to the problem of defeating the erosive qualities of gunpowder. Brearley was a man of imagination. The immediate result of his observations in the factory was a detailed .report, in which ho set forth his. understanding of the causes of erosion in rifle barrels. He decided that it could be minimised in two ways. The_ first was by the use of modified explosives, and the second was by the substitution of a new metal. Brearley was not much interested in explosives: he had boon through ’the-Russian social revolution of 1905, having had; five years’ experience in a British steel works at Riga. Perhaps the experience of 1905 created in him an aversion from explosives; in any case he disregarded the first solution' and began to search for a new metal.

He envisaged one which would not erode, and he was led naturally to imagine what its properties would have to bo. It would have to bo incapable of hardening by’ sudden cooling, and it was essential that it should resist wear at high temperatures. His requirements thus in mind, he began in a practical manner to seek fulfilment In setting out upon bis task Brearley little dreamed that in his search for a more efficient rifle barrel for soldiers he would make a discovery which was to have a tremendous effect upon the lives of millions of people in no way connected with military’ operations. Although he had spent the greater part of his life in Sheffield, Brearley had never been in a cutlery facto®’. Knives, as utensils, hardly interested him, although as pieces of metal they might have attracted his attention. Nothing, however, was further from his mind than cutlery when he began experimenting with new alloys of steel suitable for better rifle barrels. EXPERIMENTS WITH CHROMIUM STEEL.

In October, 1912, ho produced, some specimens of chromium steel by the old crucible process; as he had half expected, they did not conform to his requirements, and ho produced other batches in _an electric furnace. One of these highly pleased him; it contained less than i per cent, of carbon and 12 per cent, of chromium. The word “stainless ” had not yet entered his mind. Up to this point the elimination of erosion was his solo pursuit, and it did not occur to him that a steel which would not erode would also bo impervious to stain. Samples of his new steel were sent to the small arms factory for trial in the manufacture of rifles, but they excited little interest. As befitted a thoroughgoing analyst, it was his practice to examine every property of any new substance which ho produced. It was in his microscopic examinations of sections of the new steel that he discovered that the acids used to etch, or corrode, the surface of steels had no effect upon the new product. Excited by this discovery, he tried vinegar and other food acids upon the unnamed metal. They had no effect upon it whatever. Then, for the first time, he thought of cutlery. Here was a steel which would not stain! Brcarley had not realised, however, that the man in the street, or the man in the steel works for that matter, would laugh at his suggestion of such a thing as steel which would neither stain nor rust. Everyone knew that if a piece of steed were loft lying about it would rust. What else could be expected of it? Ever since man's discovery of iron - and steel they had rusted. Here was a man proclaiming that he had thwarted Nature. Bcarley’s own employers failed to grasp the significance of his claim.

■ For two years incessantly he urged the use of bis new chromium steel in the manufacture of cutlery.'. Ultimately some of the steel was sent by his employers to two Sheffield, cutlers. On account of the difficulties in forging, grinding, and hardening they' pronounced it useless, although they made some knife blades. The first “rustless ” knives—the word stainless was still unspoken—were sent to Bearley’a employers with a report that they, were useless. When Bearley heard the cutlers’ report his comment was to the effect that in all probability the blades had never been used except as paperknives.

This period of disheartening setback came to an end, however, in July, 1914. Brearley met a man named Ernest Stuart, who was a cutlery manager. Brearley discovered that they had both been to school under the same master. Stuart listened sympathetically to Brearley’s protestations of belief in his rustless steel, but he good-naturedly refused to believe that rustless steel could exist. A BEGINNING WITH CHEESE KNIVES. “ To-day only sixteen years later, Sheffield produces more than 2,GOD tons of stainless cutlery each year. The, quantity produced in the United States is probably even larger. Although Stuart refused to believe that a rustless steel could exist, he thought that Brearley’s new metal might be useful for other purposes, and he consented to make some cheese knives out of it. Within a week he was convinced that the new metal was all that its inventor claimed it to be. The cheese knives were both rustless and stainless, and he immediately coined for them the trade name “ llusuorstain.” Ho was the first man ‘to call the new metal “ stainless ” steel. The steel was so hard, however, that all Stuart’s stamping tools were ruined in affixing his trade mark to the knives. Brearley has some of those first knives in use in his own home in England to-day, and they afe as good as they were "on the day they were made. Brearley offered to help the enterprising cutlery manager in his manufacturing processes, suggesting various heat treatments, but Stuart did not heed him, and the second batch of knives, although they did not spoil his stamping tools, were hard and brittle, and snapped like pieces of cast-iron. Brearley knevv the exact, temperatures at which his new steel should be worked and hardened. Ho went to the . r’s workshops, and in one afternoon they made a dozen or more knife blades. They s ed to he satisfactory, and a prelim: v quantity of them was made. ~o were distributed among Stuart’s ends and acquaintances, with a request that if any of them showed any signs of_ stain after contact with any foods, fruit, or condiments they should be returned. None of them was returned, and the cutler realised the immense possibilities of the new metal. In two months he had ordered seven tons of it from Brearley’s emnloyers. Encouraged by this order, the inventor again approached his employers, suggesting that large stocks of the material might be sold to cutlery manufacturers, and that ho should benefit from such sales. AN AMERICAN PATENT.; To his dismay his employers, with whom he had been associated nearly

all, his life,- would not consider his representations. ' They, claimed that as lie had made his discovery while in * their 1 employ it was their property. As it seemed that the. benefits of his discovery were to be' lost to himself he resigned from the works. in which he had spent nearly thirty years. Fortunately he had a small independent source of income, and was not in immediate financial need. In 1915 a a American patent expert named Haddocks sought him out. - • Haddocks was a man who might well have been content to retire-from; such active pursuits as the patenting and commercial exploitation of a newmetal, for he was 75 years of age. After much opposition' From- vested interests Haddocks obtained . a . United States patent for making stainless steel in Brearley’s name. Brearley’s former employers, although they were unaware of all the processes in the manufacture of , his stainless steel, persisted in attempts_ to produce articles made from it. until, after repeated appeals on his part they eventually acknowledged the discovery as his and extended commercial rights to' him. Every year new uses. for stainless steel are discovered. The working narts of many kinds of machinery are made of it, and it is particularly suitable for parts of pumps whicn, before the advent of stainless steel, were an unceasing source of trouble to engineers. Chemical manufacturers find it invaluable for the handling of substances which would quickly ruin other metal containers and pipes with which they came in contact. The manufacturer of a fanious' motor ’car has in-corporated'-stainless steel in certain weather-exposed'parts'of his vehicle. 1 lunched with Mr Brearley in Melbourne not long ago. When wd sat down at a table be picked up a bi'ead-and-butier knife and- pointed to the trade mark. “You see,” lie said, “they lay my own knives for me wherever t go.”