1824.J M. Breant on Damasked Steel. 267 



Article X. 



Description of a Process for making Damasked Steel. 

 By M. Breant.* 



It appeared from M. Breant's former experiments, published 

 in the " Bulletin de la Societe d'Encouragement," for 1821, that 

 the watered or wavy appearance on the eastern damasked steel 

 is not mechanically produced, but the result of a particular com- 

 position, and he has at length ascertained that it is owing to an 

 increased quantity of carbon incorporated with the steel beyond 

 the proportion contained in the common sorts. According to 

 this chemist, the effect depends on two states of combination in 

 which the carbon exists in the steel, and numerous experiments 

 have enabled him to give the rules for several processes for the 

 manufacture of different kinds of cast steel. 



" The watered (moiiee) surface of the oriental sabres has led 

 to the supposition that they are made from what- is called stuff" 

 (etoff'e), that is a bundle of steel bars, or wires, forged and 

 welded together, and twisted in different directions. 



" A long series of experiments has taught me that the sub- 

 stance of the oriental damask is a fused steel, more loaded with 

 carbon than our European steels, and in which, by means of a 

 proper management in the cooling, a crystallization of two dis- 

 tinct compounds of iron and carbon is affected. 



" This separation is the essential condition ; for if the fused 

 matter be suddenly cooled, as is the case when cast into small 

 ingots, no appearance of damask is perceptible ; it is only to be 

 discovered by using a magnifying lens. 



" Iron and carbon form at least three distinct compounds ; 

 steel, which is at one of the extremities of the series, contains 

 but a very small proportion (1- 100th) of carbon ; plumbago, on 

 the contrary, contains from 12 to 15 times more carbon than 

 iron. Black and white cast iron hold the middle place." 



As bodies combine chemically only in definite proportions, if 

 in making steel there be a deficiency of carbon, a portion of the 

 iron will remain merely in a state of mixture with the steel that 

 is formed, the quantity of the latter depending on the quantity 

 of combined carbon ; and on cooling the mass slowly, the more 

 fusible particles of steel will have a tendency to unite together, 

 and separate from the iron. This alloy, therefore, will show a 

 damasked surface, but it will be white, ill defined, and the metal 

 being mixed with iron will not be capable of much hardness. 



The exact proportion of carbon requisite to convert all the 

 iron into steel will give a homogeneous mass ; and conse- 



• From the Annales des Mines. 



