ALLOYS.

ALLOYS.

ALLOYS.

   Fig. 1. — (Heycock & Neville, Phil. Trans.) Bronze containing 23.3% of tin. Slowly cooled. Magnified 18 diameters. Dark parts are rich in copper, light parts in tin.

   Fig. 2. — (Ewing & Rosenhain, Phil. Trans.) Lead-tin eutectic. Magnified 750 diameters.

   Fig. 3. — (F. Osmond.) Silver-copper [copper=15%, silver=85%] reheated to purple colour. Magnified 600 diameters.

ALLOYS.

GUN-MAKING.

GUN-MAKING.

   Fig. 4. — (Heycock & Neville, Phil. Trans.) Copper-tin [tin 27.7%] chilled at 731° C. before complete solidification. Magnified 18 diameters. Blacks rich, whites less rich in copper.

   Fig. 5. — Gun steel, C.=0.30%. From top of ingot as cast, magnified 29 diameters. Whites, ferrite; blacks, carbide.

   Fig. 6. — Gun steel, C.=0.30%. From bottom of ingot as cast, magnified 29 diameters. Whites, ferrite; blacks, carbide.

GUN-MAKING.

GUN-MAKING.

GUN-MAKING.

   Fig. 7. — Gun steel, C.=0.30%. Top of ingot, forged and annealed, magnified 29 diameters. Whites, ferrite; blacks, carbide.

   Fig. 8. — Gun steel, C.=0.30%. Bottom of ingot, forged and annealed, magnified 29 diameters. Whites, ferrite; blacks, carbide.

   Fig. 9. — Gun steel, C.=0.30%. Forged and annealed, magnified 1000 diameters, showing pearlite.

GUN-MAKING.

IRON AND STEEL.

IRON AND STEEL.

   Fig. 10. — Gun steel, C. = 0.30%. Oil hardened and annealed, magnified 50 diameters.

   Fig. 11. — (Osmond.) Pearlite, steel (carbon about 1%) forged and annealed at 800° C. Magnified 1000 diameters.

   Fig. 12. — (Stoughton.) Meshes of pearlite in a network of ferrite, from hypo-eutectoid steel. Magnified 250 diameters.

IRON AND STEEL.

IRON AND STEEL.

IRON AND STEEL.

   Fig. 13. — (Stoughton.) Meshes of pearlite in a network of cementite from hyper-eutectoid steel. Magnified 250 diameters.

   Fig. 14. — (Osmond & Cartaud.) Martensite. Magnified 250 diameters.

   Fig. 15. — (Osmond.) Martensite (black) in austensite (white). Steel (carbon about 1.5%) quenched at 1050° C. in ice-cold water. Magnified 250 diameters.