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- Li, W-B., et al.
(författare)
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Laser transformation hardening of steel : II. Hypereutectoid steels
- 1986
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Ingår i: Acta Metallurgica. - : Elsevier BV. - 0001-6160. ; 34:8, s. 1533-1343
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Tidskriftsartikel (refereegranskat)abstract
- For pt.I see ibid., vol.32, p.1935 (1984). The properties of surfaces can be modified by heat-treatments using a scanning laser beam. In pt.I it was shown that the hardness and the depth of the laser-hardened layer in hypereutectoid steels could be predicted, with reasonable accuracy, from a model which combined an analysis of heat flow with one of the kinetics of pearlite dissolution, carbon redistribution in austenite, and subsequent transformation to martensite. In the present study the model is extended to include the case of hypereutectoid steels. A new approximate solution for carbide dissolution is developed, which allows both the changes in particle size and volume fraction, and in carbon content of the austenite, to be estimated. Reasonable agreement between measured and predicted hardness for a laser treated 1% C steel are obtained. The results are presented as laser processing diagrams which show how the case depth and hardness depend on the process variables
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| 2. |
- Li, Wen-Bin, et al.
(författare)
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On densification and shape change during hot isostatic pressing
- 1987
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Ingår i: Acta Metallurgica. - Cambridge : Elsevier BV. - 0001-6160. ; 35:12, s. 2831-2842
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Tidskriftsartikel (refereegranskat)abstract
- When the temperature of a powder compact is raised, heat diffuses inwards from the surface. If the compact is under pressure (as it is during HIPing), the surface layers start to densify, increasing the local thermal conductivity. Under certain conditions a densification front then propagates into the powder, and this leads to changes of shape of the compact, which is no longer identical to the preform shape. The conditions which lead to non-uniform densification are analysed and the consequences are discussed, and compared with experiments
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