October 7, 1909] 



NA TURE 



437 



T 



THE IKON AND STEEL INSTITUTE. 



HE autumn session of the Iron and Steel Institute 

 commenced on Tuesday, September 28. Meetings for 

 the reading and discussion of papers were held on Tuesday, 

 Wednesday, and Thursday at the Institution of Civil 

 Engineers, and were attended by a large number of 

 members. In the absence of the president, the chair was 

 taken by Lord Airedale, supported by the Duke of Devon- 

 shire, who presented the Carnegie gold medal to M. A. 

 Portevin, in recognition of his researches on steel alloys. 



A short paper on the production of iron and steel by 

 the electric smelting process, by E. J. Ljungberg^ gives 

 information regarding some experiments made in Sweden 

 at the works at Uomnarfvet. The latest form of furnace 

 emploved resembles a common blast-furnace having three 

 carbon electrodes fed by three-phase alternating current at 

 about 40 volts, 60 cycles, and 9500 amperes. These elec- 

 trodes take the place of tuyeres. The furnace has been 

 running for 1903 hours, and has produced 280 tons of iron , 

 containing from 0-95 per cent, to 309 per cent, of carbon. 

 In producing this quantity there was used 442 tons of 

 ore, 24 tons of lime, 41 tons of coke, 58 tons of charcoal, 

 6-5 tons of electrodes, and 891,623 kilowatt-hours of 

 current. No *r whatever is used in the process. The 

 manufacture of iron and steel direct from ore Ijy electrical , 

 means is of importance in a country Uke Sweden, possess- 1 

 ing practically no coal mines, but having numerous water- 

 falls available for the generation of electricity. A com- 

 mercial start has been made by the installation of three 

 large furnaces in Canada at Sault Ste. Marie. 



The difficulties encountered in tests for determining the 

 economy of steam engines used in driving reversing rolling- 

 mill engines are explained in a paper by Mr. C. A. Ablett. 

 Such tests are usually carried out by indicating the engine, 

 and so estimating the steam consumption per indicated 

 horse-power, or by measuring the feed water or coal con- 

 sumption in cases where the boilers supplying the engine 

 can be isolated. In the latter case the result can be ex- 

 pressed in pounds of steam or coal per ton rolled, provided 

 a record is kept of the total weight of steel passed through 

 the mill during the test. The author also describes how 

 the power consumed in electrically driven mills may be 

 obtained by means of an ordinary integrating wattmeter. 

 The results of such tests are expressed easily in kilowatt- 

 hours per ton. Five steelworks have decided to adopt 

 electrical driving since the last autumn session of the 

 institute, making more than twenty firms in all which have 

 come to this decision. The author gives some results of 

 electrically driven rolling mills, from which we quote the 

 highest and the lowest. In rolling flange rails, 100 lb. 

 per yard, from 2-ton ingots, output 30 tons per hour, 

 480 kilowatt-hours per ton were required. In producing 

 32-inch by g-inch slabs from 6-ton ingots measuring 

 36 inches by 195 inches, output 40 tons per hour, 43 kilo- 

 watt-hours were required. 



An interesting paper on the growth of cast irons after 

 repeated heatings was contributed by Profs. H. F. Rugan, 

 of Louisiana, and H. C. H. Carpenter, of Victoria Uni- 

 versity, Manchester. The fact that certain types of cast 

 iron grow after repeated heatings has long been familiar 

 to engineers. Cast iron annealing ovens 8 feet in length, 

 3 feet in diameter, and ij inches in thickness, kept red 

 hot for prolonged periods, sometimes grow to 9 feet in 

 length in the course of use. The conditions under which 

 the maximum growth occurs were first investigated, and, 

 as a result, a period of four hours at 900"^ C. was chosen 

 for the experiments. For growth to take place, repeated 

 heating and cooling are required. In the tests, three com- 

 mercial cast irons were examined, the test bars being 

 heated in a cast-iron muffle protected by another mufBe 

 of fire-clay. The bars grew at different rates and to 

 different extents, constant volume being reached after 

 ninety-four heats. The growth in volume varied from 

 3i;-2i per cent, to 37'So per cent. An increase in weight 

 of from 7-82 per cent, to 8-6o per cent, was observed. 

 The connection of growth and chemical composition was 

 investigated on a series of iron-carbon alloys containing 

 no graphite. An alloy was found the volume of which 

 remains constant even after repeated heatings at about 

 900° C. This alloy is a white cast iron having about 



NO, 2084, VOL. 81] 



3 per cent, of carbon and only small quantities of 

 other constituents, of which silicon is the most importanl, 

 and this should not e.xceed 02 per cent, to 0-3 per cent. 

 The influence of silicon was examined in a series of iron- 

 carbon-silicon alloys. The growth was found to be roughly 

 pioportional to the silicon present. In grey irons there 

 are alloys the growth of which in air on heating is due 

 entirely to oxidising gases penetrating their interior; in. 

 others, originally dissolved gases contribute to some extent 

 to the giowth. 



Some experiments carried out at the Clarence Ironworks, 

 Middlesbrough, are described in a paper by Mr. Greville 

 Jones. These experiments had for their object the deter- 

 mination of whether the principal saving in fuel in blast- 

 furnaces using dry air blast was due to the uniformity of 

 the blast or to its dryness. Two furnaces were used, 

 both of the same size and carrying the same load. For 

 comparison, one of these was run with dry blast, and 

 the other was supplied with blast in which the moisture 

 was gradually increased up to 4 grains per cubic foot 

 during the first of the four weeks over which the experi- 

 ments extended. No appreciable difference was found in 

 the working of the two furnaces. 



Mr. R. S. Moore dealt with the fuel economy of dry 

 blast in a subsequent paper. The author was associated 

 with Mr. Jones in the tests at the Clarence Ironworks, 

 and believes that the results of these tests point strongly 

 to the fact that the great heat saving of the Gayley dry 

 blast must be due to its dryness. 



In another paper Mr. F. J. R. Carulla considers the 

 development of the process of manufacturing artificial 

 magnetic oxide of iron. Dr. William Gregory, of Edin- 

 burgh, first observed that when a solution of protosulphate 

 of iron is divided into two equal parts, one of which is 

 peroxidised, then mixed with the other, and precipitated 

 by ammonia at a boiling heat, a black oxide is obtained 

 which does not attract oxygen in drying, and is highly 

 magnetic. Its composition must be 2FeO-l-Fe,Oj, as the- 

 two solutions contain equal quantities of iron, and Gregory 

 suggests that it may occur native as a variety of magnetic 

 iron ore. Dr. Wiilffing first worked out its industrial 

 manufacture from waste liquors. Notwithstanding dilTicul- 

 ties, the product is diflicult to spoil in the making, and 

 the great protective value of the Gregory-Wiilffing magnetic 

 oxide of iron paint is acknowledged by all who have had 

 any experience of it. 



The serviceable life and cost of renewals of permanent 

 way of British railways were dealt with in a paper by 

 Mr. R. Price-Williams. The total annual cost of the 

 maintenance and renewal of the permanent way and works 

 now amounts to 15 per cent, of the entire working 

 expenses, which for some years past have reached the 

 high figure of 63 per cent, of the entire railway gross 

 receipts. The wear and tear of permanent way during the 

 last ten years amounts to 5039 miles of railway, which 

 have become worn out and have been replaced in most, if 

 not all, cases with stronger and better materials. 



Dr. J. Newton Friend, in a paper on the corrosion of 

 iron, points out that the ionisation of water, which forms 

 the base of the electrolytic theory of corrosion, is purely 

 an assumption of which we have no definite proof. Kohi- 

 rausch showed that water offers the greater resistance to 

 the passage of an electric current the more carefully it is 

 purified. Not a few chemists maintain that if absolutely 

 pure water could be obtained it would be found to be in- 

 capable of conducting an electric current — in other words, 

 that it would not be capable of ionisation. Leduc has 

 directed attention to the extreme difficulty of removing 

 every trace of dissolved gases from water by boiling. The 

 author points out that the results obtained by Kohlrausch 

 and Heydweiller may be simply a measure of the extent to 

 which the dissolved gases remain in solution under the 

 special conditions of the experiments. If such is really 

 the case, the electrolytic theory of corrosion becomes a 

 myth, whereas the acid theory is unaffected by it. 



Dr. Friend read another paper on the action of air and 

 steam on pure iron. His experiments show that pure iron 

 combines with ordinary air and with air dried over phos- 

 phorus pentoxide with increasing readiness as the tempera- 

 ture rises. Below 150° C. the oxidation proceeds too 

 slowly to be readily detected. Pure iron becomes tarnished 



