Effect of Tungsten on Creep Behavior of 9%Cr–3%Co Martensitic Steels

Published on Dec 18, 2017
· DOI :10.3390/MET7120573
Alexandra Fedoseeva10
Estimated H-index: 10
,
Nadezhda Dudova13
Estimated H-index: 13
+ 1 AuthorsAndrey Belyakov41
Estimated H-index: 41
Sources
Abstract
The effect of increasing tungsten content from 2 to 3 wt % on the creep rupture strength of a 3 wt % Co-modified P92-type steel was studied. Creep tests were carried out at a temperature of 650 °C under applied stresses ranging from 100 to 220 MPa with a step of 20 MPa. It was found that an increase in W content from 2 to 3 wt % resulted in a +15% and +14% increase in the creep rupture strength in the short-term region (up to 103 h) and long-term one (up to 104 h), respectively. On the other hand, in the long-term creep region, the effect of W on creep strength diminished with increasing rupture time, up to complete disappearance at 105 h, because of depletion of excess W from the solid solution in the form of precipitation of the Laves phase particles. An increase in W content led to the increased amount of Laves phase and rapid coarsening of these particles under long-term creep. The contribution of W to the enhancement of creep resistance has short-term character.
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