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BELL SYSTEM TECHNICAL JOURNAL 



FiK. A 

 (c) A cast steel of 0.5% carbon in \\liicli the Widnianstiitten or clcavaKC 

 structure has developed somewhat similarly to that shown in the meteorite. The 

 physical characteristics of the steel arc dependent on the structural arraiiRemcnt 

 of its constituents, in this case pearlite (dark) and free ferritc (light). By 

 suitable heat treatment this coarse structure may be refined and the physical 

 properties of the steel greatly improved. Magnification 100 X. 







Fig. A 

 (d) The same steel as illustrated in "C" but after being refined (heated to 

 1000°C; air co(dcd ; reheated to 650°C, and again air cooled.) Magnification 

 100 X. 



