Purity in Iron
The following extract is made rfom a paper on “Real Purity in Iron” read by G. H. Charls, of the American Rolling Mill Co., Middletown, O., at the recent meeting of the National Corrugated Culvert Association: In striving for the greatest possible purity in iron for years the only ingredients considered were sulphur, phosphorous, carbon, manganese and silicon. No attention was given to other imprities which have been found to be just as harmful, possibly more so. It is now known that the elimination of all impurities that differ electrochemically from iron is absolutely essential if the highest grade of durability is desired. The reduction of sulphur, phosphorous, carbon, manganese and silicon contents of metal made in the open hearth furnace, with a total disregard of the copper, oxygen, hydrogen and nitrogen contents, means that the metal low in the first five impurities may be very inferior to the poorest grade of Bessemer steel. Especially is this true if the manganese and oxygen contents are not carefully reduced to a minimum. Manganese is the only positive element appearing in iron or steel. When moisture starts an electrolytic action the manganese in steel (which is always there in segregated form) must of necessity go into solution and be carried to the negative pole. This is the cause of that form of corrosion known as “pitting” which is so common and noticeable in steel, and is the reason manganese is regarded as perhaps the most harmful impurity. Oxygen, on the other hand, is perhaps the most negative impurity, and is therefore a great accelerator of the electrolytic action, causing rust and quick decay. For this reason its effect is almost as disastrous as the manganese. Therefore it is evident that in order to positively know just how pure the metal is the consumer must either submit samples to a reliable testing laboratory or insist upon the manufacturer giving a written guarantee or bond insuring the total amount of all impurities appearing in his product, including sulphur, phosphorous, carbon, manganese, silicon, copper, hydrogen, oxygen. It is no longer necessary to grope in the dark on this subject. Science and experience have blazed the trail and the above facts cannot be ignored or disputed. It has been found that an iron containing a minimum amount of all impurities and guaranteed by the manufacturers to be less than sxteen-hundredths of one per cent., is durable, reliable and worthy of confidence.
V. E. Arnold, Dist. Manager of the Pittsburgh Meter,Co.’s New York office, left this week for a month’s stay in Florida. He will be accompanied by his daughter Mildred.