The effect of heat treatment and composition on the toughness and hardness of mar aging alloys based on Fe-Ni-Mn is first summarised. Age hardening data for an Fe-12Ni-6Mn alloy have been subjected to quantification. In the early stages of aging, the increase in hardness (∆H) has been found, both practically and theoretically, to follow the relationship ∆H = (Kt)n, where t is the isothermal aging time and K a temperature dependent rate constant, giving an activation energy of 79 ± 1.3 kJ mol−1 for the process. This is reasonablefor pipe diffusion of Ni and Mn, as is the value of 3·9+2.4-3.0 × 10-8 m2 s-1 for the effective diffusion coefficient Do for the temperature range 350–425°C.
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References
1.
PRKASM. D. and SNITSARV. I.: Phys. Met. Metallogr., 1964, 17, 400–407.
2.
TANAKAT., SUZUKIT., and YODOGAWAM.: J. Jpn Inst. Met., 1967, 31, 1075–1082.
ROMIGA. D., Jr and J. I. GOLDSTEIN: Metall. Trans. A, 1980, 11A, 1151–1159.
18.
SUZUKIT.: J. Jpn Inst. Met., 1968, 32, 1019; and Trans. Jpn Inst. Met., 1970, 11, 257.
19.
MARTINJ. W.: in ‘Micromechanisms in particle hardened alloys’, 53-54; 1980, Cambridge, Cambridge University Press.
20.
LEDBETTERM. M. and REEDP. R.: J. Phys. Chem. Ref. Data, 1973, 2131, 531–617.
21.
BARRETTC. S.: ‘Structure of metals’, 2nd edn, 641; 1952, New York, McGraw-Hill.
22.
WILSONE. A.: J. Iron Steel Inst., 1968, 206, 164–168.
23.
ZENERC.: J. App!. Phys., 1949, 20, 950.
24.
CHRISTIANJ. W.: in ‘The theory of transformations in metals and alloys’, 2nd edn, 488; 1975, Oxford, Pergamon.
25.
JOHNSONW. A. and MEHLR. F.: Trans. AIME, 1939, 135, 416.
26.
AVRAMIM.: J. Chem. Phys., 1941, 9, 177.
27.
BURICEJ.: in The kinetics of phase transformation in metals’, 46; 1965, Oxford, Pergamon.
28.
COTTRELLA. H. and BILBYB. A.: Proc. R. Soc. (London) A, 1949, A62, 49.
29.
HAMF. S.: J. Appl. Phys., 1959, 30, 915.
30.
PETERSD. T. and CUPPC. R.: Trans. AIME, 1966, 236, 1420–1429.
31.
ICAURI. and GUSTW.: in ‘Fundamentals of grain and interphase boundary diffusion’, 2nd edn, 132; 1989, Stuttgart, Zeigler.
32.
ICAURI., GUSTW., with L. KOZMA: in ‘Handbook of grain and interphase boundary diffusion data’, Vols. 1 and 2, 587-588, 767, 776-779; 1989, Stuttgart, Ziegler.
33.
PREDELB. and GUSTW.: Arch. Eisenhuttenwes., 1972, 43, 721.
34.
PREDELB. and GUSTW.: Arch. Eisenhuttenwes., 1972, 43, 657.
35.
WANDELTK. and CHUANGT. J.: Proc. 7th Int. Vacuum Cong. and 3rd Int. Conf. on ‘Solid surfaces’, Vienna, Austria, 1977, International Union for Vacuum Science, Technology, and Applications, 2091.
36.
CHUNGT. J. and WANDELTW.: Surf. Sc!., 1979, 81, 355.
37.
JAMESD. W. and LEAKG. M.: Philos. Mag., 1965, 12, 491.
38.
CHRISTIANJ. W.: ‘The theory of transformation in metals’, 1st edn, 638-640; 1965, Oxford, Pergamon.
39.
TWEETA. G.: Phys. Rev., 1957, 106, 221.
40.
HUSBANDJ. N., MASONK. L., and CHRISTIANJ. W.: unpublished work, 1959.
41.
SPEICHG. R. and FISHERR. M.: in ‘Recrystallisation, grain growth and texture’, 563; 1966, Metals Park, OH, American Society for Metals.
42.
GUYA. G.: in ‘Essentials of materials science’, 337; 1996, Tokyo, McGraw-Hill, Kogakusha.
43.
REPPICHB. and SCHUMANNG.: Mater. Sci. Eng. A, 1988, 101, 171–182.
44.
DIXONP. H. and BURKEJ.: ‘Kinetics of the fi a transformation in a U-0.5 at.-%Cr alloy’, Report 4431, Atomic Energy Research Establishment, Harwell, UK, 1964.
45.
SHAHA. K., KULKARNIG. J., GOPINATHANV., and KRISHNANR.: Scr. Metall. Mater., 1995, 32, 1353–1356.
46.
RADCLIFFES. V. and ROLLASONE. C.: J. Iron Steel Inst., 1959, 191, 56–65.
47.
DUTTAB. and SELLARSC. M.: Mater. Sci. Technol., 1987, 3, 197–205.
48.
NABARROF. R. N.: Proc. R. Soc. (London) A, 1940,175A, 519–538.
