IRON AND STEEL. 



537 



clines to speak favorably of the like addition 

 to cast iron ; but it recommends the employ- 

 ment of this metal in case of the manufacture 

 of steel, as giving to the latter qualities which 

 enhance its value. We have not met with a 

 statement of the percentage of tungsten rec- 

 ommended ; but the additional cost is said not 

 to exceed about 70 cents per cwt. Ibid. 



The experiments of M. le Guen, made at 

 the military post of Brest, give a conclusion at 

 variance with that part of the report just re- 

 ferred to, which relates to cast iron. He is led 

 to conclude that cast iron, composed of old 

 and new iron in proportions which give great 

 strength, is made yet stronger by the addition 

 of less than two per cent, of tungsten. In one 

 case, after two fusions, the resistance to frac- 

 ture was increased by more than one third. 

 The superiority was maintained after several 

 fusions ; and the cast iron so treated was ren- 

 dered tougher and more elastic. The addition 

 of the tungsten was easy, as it merely required 

 pulverizing, without previous reduction. 

 Technologiste, June, 1863. 



Mr. Edward Kiley, F.C.S., finds that in cer- 

 tain sorts of iron titanium is abundant ; and as 

 this metal is found in clay, he thinks its pres- 

 ence in the former due to employment of clay 

 iron ore. In two analyses of Norwegian ore, 

 he found 36.88 and 40.80 per cent, of titanic 

 acid present. In Belfast iron ore, dried at 280 

 F., he found 3 per cent, of this mineral. He 

 believed that titanium, like manganese, exerted 

 some beneficial influence on the manufacture 

 of iron and steel : possibly, the titanium, by 

 its affinity for carbon and nitrogen, acted as a 

 carrier of cyanogen to the steel. 



Chemical Composition of Cast ^Iron. M. 

 Rammelsberg, in a communication to the 

 Academy of Sciences of Berlin, gives the re- 

 sults of his recent analysis of the cast iron of 

 Musen. He found this to contain 5.8 per cent, 

 of combined carbon, and also graphite the 

 latter presenting itself in lumps. Silicium was 

 also present, and, apparently, titanium. The 

 graphite from the iron, after being washed in 

 ether and alcohol, and dried, presented the as- 

 pect of pure graphite. The author concludes 

 that it is correct to regard specular iron as a 

 combination of iron and carbon ; but that 

 Karsten is wrong in supposing this the form 

 which contains the largest proportion of car- 

 bon. Without having its external characters 

 altered, such iron may contain variable quan- 

 tities of carbon. Those irons which have most 

 carbon in them also contain most silicium. 



The Effect of Tempering on Steel. Karsten 

 had remarked that, in acting upon untempered 

 steel by acids, there is retained as residue a 

 graphitic material which, when tempered steel 

 is substituted in the process, does not appear ; 

 the graphitic material he considered to be a 

 definite combination of six atoms of carbon with 

 one of iron. Capt. Caron has lately taken up 

 this subject, of the carbon in steel, with es- 

 pecial reference to the influence exerted 



upon the latter by hammering, and by tem- 

 pering. 



In the many experiments made by Caron 

 with a view to this question, he has never 

 found Karsten's definite carbide of iron, or 

 graphite' 1 ; but he observed that the supposed 

 carbide of iron varied in composition, not only 

 with the quality of the steels and the nature of 

 the solvents employed, but further, even with 

 the form and the dimensions of the piece of 

 steel analyzed. He was thus led to infer that 

 the supposed carbide of iron is probably no 

 more than a mixture of the carbon and met- 

 al, and in which the latter happens to be me- 

 chanically protected by the carbon against the 

 solvent action of the acid used. He according- 

 ly selected pieces of steel which had passed 

 through the process of cementation, but were 

 in three different conditions ; namely, 1, tin- 

 tempered ; 2, do., but hammered ; 3, tempered. 

 To each of these, placed in separate vessels, 

 was added a like quantity of concentrated chlor- 

 hydric acid ; and they were then together sub- 

 jected to heat in a stove. It was readily perceiv- 

 ed that the graphitic matter was not in equal 

 quantity in the three vessels ; and that, in the 

 one holding the tempered steel, it was well- 

 nigh wanting. Separating by a course of 

 treatment detailed in the article we quote from, 

 and analyzing the graphitic material afforded 

 by the three samples of steel, the following 

 were the results obtained. The three condi- 

 tions of steel, in quantities of 100 grammes of 

 the metal of each dissolved, yielded for the 

 nntempered, 1.624 grammes of residue ; for the 

 hammered, 1.243 grammes; and for the tem- 

 pered, 0.240. And the analyses of these 

 showed : 



Here, the effect produced in a complete manner 

 by tempering, is found to be in part realized by 

 hammering : and the qualities which constitute 

 steel appear to be enhanced at the same time 

 that the proportion of the carbon in intimate 

 combination with the iron is augmented. At 

 the same time that hammering improves steel, it 

 diminishes the proportion of carbon that acids 

 can separate from the latter ; and these appar- 

 ently related results are both seen to be mani- 

 fested, and in much higher degree, in steel that 

 has been subjected to tempering. But the 

 effect of heat is directly the opposite, both 

 upon steel and cast iron ; the effect of anneal- 

 ing either of these, for some hours or days, 

 being continually to increase the proportion 

 of the carbon that acids will set free from 

 the metal, at the same time that the strength 

 and quality of the latter are impaired. M. Caron 

 concludes that the affinity of carbon by it- 

 selffor iron, is feeble ; but that this affinity 



