372 On the Alloys of Steel. 



M. BcrUiier, who first made the alloy of steel and chro- 

 mium *, sjieaks very iavourably of it. We have made only 

 two experiments. 1600 grains of steel, with 16 of pure chrome, 

 were packed into one of the best crucibles, and placed in an 

 excellent blast furnace : the metals were fused, and kept in 

 that state for some time. The fused button proved good and 

 forged well: although hard, it showed no disposition to crack. 

 The surface being brightened, and slightly acted on by dilute 

 sulphuric acid, exhibited a crystalline appeai'ance; the cry- 

 stals, being elongated by forging, and the surface again po- 

 lished, gave, by dilute acid, a very beautiful damask. Again, 

 1600 grains of steel with 48 of pure chrome Avere fused: this 

 gave a button considerably harder than the former. This too 

 was as malleable as pure iron, and also gave a very fine da- 

 mask. Here a phenomenon rather curious was observed : the 

 damask was removed by }3olishing, and restored by heat witli- 

 out the use of any acid. The damasked suiface, now coloui'ed 

 by oxidation, had a vei-y novel appearance : the beauty was 

 heightened by heating the metal in a way to exhibit all the 

 colours caused by oxidation, from pale straw to blue, or fi^om 

 about 430 to 600*^ of Fahrenheit. The blade of a sabre, or 

 some such instrument, made fi'om this allo}'^, and treated in 

 this way, would assuredly be beautiful, whatever its other pro- 

 perties might be; for of the value of the chrome alloy for edge 

 tools we are not prepared to speak, not having made trial of 

 its cutting powers. The sabre blade, thus coloured, would 

 amount to a proof of its being well tempered; the blue back 

 would indicate the temper of a watch sjn-ing, while the straw 

 colour towards the edge viould announce the requisite degree 

 of hardness. It is confessed, that the operation of tempering 

 any blade of considerable length in this way, wouhl be attended 

 with some difficulty. 



In the account now given of the different alloys, only one 

 ti'iple compound is noticed, namely, steel, iridium and osmium; 

 but this part of the subject certainly merits further investiga- 

 tion, offering a wide and interesting field of research. Some 

 attempts to form other combinations of this description proved 

 encouraging, but we were prevented, at the time, by various 

 other avocations, from bestowing on them that attention and 

 labour they seemed so well to deserve f . 



It is a curious fact, that when pure iron is substituted for 

 steel, the alloys so formed are much less subject to oxidation. 

 3 per cent, of iridium and osmium fused with some pure iron, 



* Annalrs de Clihnir, wii, 55. 



•|- It is oar intention to contiiuie these cxpcrinicnts at every opportunity ; 

 but tht'j- arc laborious, and rt-fjuire much time and patience. 



gave 



