MALLEABLE CAST IRON. 



395 



MALLEABLE CAST IRON. 



211. This term is usually applied to cast iron which 

 has been subjected to an oxidising process after it has been 

 cast into the required shape. This is effected by 

 surrounding the casting by either haematite ore or 

 manganese oxide, and exposing it to a red heat for 

 several days or weeks, according to the size of the casting. 



The strength of malleable iron is greater than the 

 original strength of the cast iron from which it has been 

 produced. It becomes slightly ductile, and its modulus 

 of elasticity is raised. Mr. A. Martens gives the following- 

 average results of some tests on this metal, both for 

 pieces which have been welded and for the unwelded 

 metal : 



I MR. A. MARTENS' TESTS ON MALLEABLE CAST IRON. 

 (AVERAGE.) 



The following results of tests on malleable cast iron 

 are given by Mr. Ashcroft. Two sets of experiments 

 were made, the first on material cast in 1884, and the 

 second cast in 1885. These metals had respectively the 

 following analysis : 



ANALYSES OF MALLEABLE IRON CASTINGS. 



J Min. Proc. I.C.E., vol. Ixxxviii., page 528. 



