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Non-Homogenous Precipitation Annealing of Maraging Steels

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Abstract:

Nickel maraging steels in the as-delivered state show a microstructure consisting primarily of oversaturated lath martensite. The final mechanical properties are achieved with precipitation annealing, during which the dissolved alloying elements start to precipitate. The newly-formed precipitated phases efficiently hinder shifts of dislocations, which results in considerable changes of the mechanical properties. Strength and hardness thus essentially increase whereas the material shows a relatively high fracture toughness. The precipitated phases formed during precipitation annealing also cause some distortion of a workpiece and transformational residual stresses on the micro and macro scales. Linear strains after precipitation annealing range from -0.05% to -0.1% and depend primarily on temperature/time conditions during the precipitation process. The non-homogenous annealing such as laser annealing produces temperature-induced residual stresses which are combined with transformational stresses. These stresses are expected to be lower and much more different than the stresses occuring in comparable classical heat-treated steels, however they cannot be neglected due to the exceptional performance of maraging steels and also their employment with high-demanding products. The results of the residual stress measurements after laser-induced and classical heat treatments of Ni-Co-Mo maraging steel with 12% nickel are presented.

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Periodical:

Materials Science Forum (Volumes 490-491)

Pages:

469-474

DOI:

https://doi.org/10.4028/www.scientific.net/MSF.490-491.469

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Online since:

July 2005

Authors:

Janez Grum, Martin Zupančič

Keywords:

Laser Hardening, Maraging Steel, Microstructure, Precipitation, Residual Stress, Temperature Cycle

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© 2005 Trans Tech Publications Ltd. All Rights Reserved

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References

[1] E.A. Wilson: Quantification of Age Hardening in an Fe-12Ni-6Mn Alloy, Scripta Materialia, Vol. 36, No. 10 (1997), pp.1179-1185.

DOI: 10.1016/s1359-6462(97)00006-7

Google Scholar

[2] R.F. Decker, S. Floreen: Maraging steels - the First 30 Years; R.K. Wilson: Maraging Steels: Recent Developments and Applications, TMS, Warrendale (1988), pp.9-12.

Google Scholar

[3] W. Sha: Thermodynamic Calculations for Precipitation in Maraging Steels, Mat. Science and Technology, 2000, Vol. 16, pp.1434-1436.

DOI: 10.1179/026708300101507415

Google Scholar

[4] P.P. Sinha et Al: Effect of Aging in Microstructure and Mechanical Properties of Cobalt Free 18% Maraging Steel, Material Science and Technology, Vol. 14 (1988), pp.1-9.

Google Scholar

[5] J. Grum, M. Zupančič: Suitability Assessment Of Replacement Of Conventional Hot-Working Steels With Maraging Steel. Part 1, Mechanical Properties Of Maraging Steel After Precipitation Hardening Treatment. Z. Met. kd., 2002, Bd. 93, Hf. 2, pp.164-170.

DOI: 10.3139/146.020171

Google Scholar

[6] Verhoeven J.D.: Chapter 11: Precipitation from Solid Solutions, Chapter 14: Some Aplications of Physical Metallurgy, Fundamentals of Pysical Metallurgy (1974), pp.363-420, 513-555.

Google Scholar