46 JOURNAL AND PROCEEDINGS 



Manufacture and Properties of Malleable 



iron. 



Bead before the Hamilton Scientific Association, 

 February 21st, 1907. 



BY S. B. CHADSEY, B.A., SC. 



The material, regularly known in commercial circles as 

 Malleable Iron, is more accurately, though less conveniently, 

 described as Malleableized Cast Iron, and may be defined as a 

 cast iron of a special composition which has been rendered 

 soft and malleable by a more or less prolonged heat treatment 

 or annealing. There are branches of engineering and manu- 

 facture in which it is rarely met with, while in other lines it 

 constitutes one of the most important materials of construc- 

 tion, and is so largely used that upon its quality depend the 

 usefulness and reliability of the structures of which it forms 

 a part. One of the most interesting of metallurgcial products, 

 both from the curious transformations which it undergoes 

 during the processes of manufacture, and from its numerous 

 applications to mechanical construction. It is strange that 

 so little information concerning it exists in the technical 

 literature of the day. This is largely due, however, to the 

 great reluctance of the older foundries to the dissemination of 

 information regarding it, and it is only during recent years 

 that a change has taken place in this respect, and that it has 

 come to be more generally recognized that greater publicity 

 alone will bring about many desired improvements. 



The foundations of the manufacture of malleable iron 

 were laid by discoveries of Reamur, about 1720, who found 

 that iron castings that were too hard to be worked could be 

 greatly softened by packing them in iron ore or hammer slag 

 and exposing them to high temperature for a number of days. 

 The industry was not founded in America, however, until 



