364 PROCEEDINGS OF THE SOCIETY. 



14:. Supersaturated Carbon Steel. — R. No. : 2196. Analysis : 

 c.c. 1-41 p.c, Mn 0*38 p.c. Treatment : Quenched 800° C. 

 Mag. : x 100. 

 Structure — very fine martensite, which, however, is just resolved at 



this magnification. 



Ref. : " Metallography " (Sauveur), p. 245 et seq. 



15. Supersaturated Carbon Steel. — R. No. : 2197. Analysis : 



c.c. 1-41 p.c, Mn 0-38 p.c. Treatmetit : Quenched 800° C, 

 tempered 400° C. Mag. : x 100. 



Membranes of cementite. The dark background is pearlite. 



Ref. : As No. 2196. 



16. Hadfield's "Era" Manoanese Steel. — R. No.-. 2035. 



Analysis: c.c. 1-2 p.c, Mn 11*98 p.c. Treatment: As cast. 

 Mag. : X 150. 



Structure of austenite here preserved at normal temperature by the 

 presence of much manganese. 



Ref.: "Metallography" (Sauveur), p. 343, figs. 320-325. 

 " Micro-Analysis " (Stead), p. 290. 



17. Hadfield's " Era " Manganese Steel. — R. No. : 2030. 



Analysis: c.c. 1*2 p.c, Mn 11*98 p.c. Treatment: Quenched 

 1000° C. water. Mag. : x 150. 



Polyhedral grains characteristic of " gamma iron." Samples possess, 

 in general, low elastic limit, great hardness, wearing power and ductility. 



Ref. : As No. 2035. 



18. Chromium Nickel Steel. — R, No. : 852. Analysis : c.c. * 70 p.c, 

 Cr 2*5 p.c, Ni 3 p.c. Treatmetit: Annealed. 3Iag. : x 600. 



As usual with quaternary steels, the pearlite is very minute ; in this 

 particular, specimen is very characteristic 



Ref: "Metallography" (Sauveur), p. 353. 

 "Metallography" (Desch), p. 66. 



19 and 20. Chromium Nickel Steel. — R. Nos. : 855 and 857. 

 Analysis: c.c 0*70 p.c, Cr 2*5 p.c, Ni 3 p.c Treatment: 

 (No. 855) Quenched 800° C. oil ; (No. 857) Quenched 800° C. oil, 

 650° C. air. Mag. : x 600. 



A minute structure, somewhat martensitic in 855 and sorbitic in 

 857. In industrial practice only steels low in carbon, nickel, and 

 chromium are used. They combine the good points in nickel steels 

 together with those of chrome steels ; high elastic limit, ductility, and 

 resilience. 



Ref: As No. 852. 



