472 



METALLURGY. (!EON AND STEEL.) 



comes much more fluid, and the impurities are 

 thrown off possibly in a gaseous form or as- 

 oxides. Mr. Lewthwaite found that by his 

 method he could produce from common Cleve- 

 land pig-metal, with only 4 per cent, of titanic 

 ore, an iron or mild steel, said by smiths, en- 

 gineers, etc., to be superior even to Low Moor. 

 The process is applicable equally to the Besse- 

 mer and Siemens methods, to converters be- 

 neath the ordinary blast-furnaces, and to the 

 foundry. From another ore than the titanic, 

 which he did not name, the author could pro- 

 duce a very desirable description of metal never 

 before known to be formed in the foundry, viz., 

 a fine steel casting, soft and pleasant to file, 

 turn, etc., which, when heated to a cherry-red 

 and plunged into water, tempers like ordinary 

 steel, without any show of water-cracking. 

 By the same process or method bronzes and 

 alloys of all colors and kinds may be made. 



M. Gruner has conducted a long series of 

 experiments upon the relative oxidability of 

 cast-iron, steel, and wrought-iron, with a view 

 to the determination of their adaptability for 

 constructions exposed to rusting and the ac- 

 tion of sea-water. Experiments made by sub- 

 mitting different kinds of iron to the action of 

 acidulated water can not be depended upon, 

 for the want of evidence that the action of 

 moist air or of sea-water is the same as that of 

 acidulated water. M. Gruner made use of an 

 apparatus in which twenty-eight similar pol- 

 ished plates of different kinds of steel and iron 

 were equally exposed to the same action, of 

 moist air, of sea-water, and of acidulated water. 

 In twenty days of experiments with moist air, 

 the chrome steels were oxidized more, and the 

 tungsten steels less, than the ordinary carbon 

 steels. The cast-irons were oxidized less than 

 the steels and wrought-irons, and among them 

 the white specular iron (spiegel), containing 20 

 per cent, of manganese, less than the gray 

 irons. The average loss in weight was about 

 half that of the steels. Sea-water was found 

 to attack iron, dissolving it like acidulated 

 water, but under entirely different conditions. 

 In a very short time chloride of iron was found 

 in the bath. Unlike moist air, sea- water at- 

 tacked cast-iron more strongly than steel, and 

 white specular iron with especial energy. The 

 tempered steels were less attacked than the 

 annealed, the soft steels less than those con- 

 taining manganese or chromium, and tungsten 

 steel less than ordinary steel having the same 

 percentage of carbon. Acidulated water dis- 

 solved gray iron more rapidly than it did steel, 

 but not the white specular iron ; the impure 

 gray iron was the most strongly attacked. 

 The results of these experiments show that, 

 while as regards chromium, manganese, and 

 tungsten, the action of acidulated water is al- 

 most the same as that of sea-water, in other 

 respects it is entirely different ; and it is totally 

 different from the action of moist air. 



M. Clemandot has introduced a new process 

 for toughening steel, which consists essentially 



in heating the metal until it -acquires a suffi- 

 cient ductility, and then subjecting it to high 

 pressure during cooling. He takes steel al- 

 ready made, heats it to a cherry-red, and sub- 

 mits it, by means of a hydraulic press, to press- 

 ures of from 1,000 to 3,000 kilogrammes per 

 square centimetre. After having been allowed 

 to cool between the two plates of the press, 

 the steel is withdrawn with all its new qualities 

 perfectly developed, and in a condition not 

 requiring any further treatment. The result 

 of the process is to impart to the steel a fine- 

 ness of grain, a degree of hardness, and a nota- 

 ble accession of strength to withstand rupture. 

 The alteration is most considerable with highly 

 carbonated steel ; and in this respect the metal 

 is made to resemble tempered steel, without 

 being in all points identical with it. 



A new crucible tool- steel, possessing remark- 

 able powers of endurance, is made at the 

 >f aindy Works, near Cardiff, Wales. It is the 

 invention of Mr. William Jenkins, who keeps 

 his process a secret. A lathe tool made from 

 a cast ingot of the Jenkins steel weighing 42 

 pounds, was tried upon cast-steel tires in com- 

 petition with tools from Mushet steel and from 

 the best Sheffield steel. It was beaten by the 

 Mushet steel, but proved greatly superior to 

 the Sheffield steel. Another tool of the Jen- 

 kins or Maindy steel, used to make a deep cut 

 across a rough cast-iron disk, eight feet in di- 

 ameter, showed but little wear, retained a good 

 cutting edge, and was capable of further work 

 without regrinding. 



The hardening of cast-steel, of the grades 

 commonly employed for tool purposes, usually 

 contracts it. This quality is frequently em- 

 ployed to reduce to exact size articles that must 

 be hardened for their purpose. An instance 

 is mentioned in which a machinist rehardened 

 a plug gauge six times in order to reduce it to 

 size. At each hardening the steel was sub- 

 jected to a close measurement test, and the suc- 

 cessive contractions could be measured, till the 

 oversized gauge had been reduced to a size 

 that required only the ordinary after-polishing. 

 The property is not universal to steel, but, in 

 some qualities of the metal, expansion rathe 

 than contraction is to be expected from repei 

 ed heatings, hardenings, and annealings. 



The method hitherto employed for treating 

 the steel in a Bessemer converter, when the 

 temperature of the bath becomes too high, has 

 been to add scrap-metal until the heat is suffi- 

 ciently reduced. By an improvement devis 

 by Capt. William R. Jones, of the Edgar Thoi 

 son Steel Works, steam is introduced into th< 

 molten metal in connection with the air-bh 

 In the use of his method, Mr. Jones found thf 

 the length of time during which steam shonl 

 be admitted into the converter depended upon 

 the size of the pipe delivering the steam, 

 well as upon such other conditions as the 

 nature of the metal, the pressure and volume 

 of the air-blast, etc. The inventor also sug- 

 gests that it may be expedient to introduce, 



