High Temperature Impression Creep Testing Of 9Cr-1Mo and 2.25Cr-1Mo Dissimilar Weldment

Abstract

The evaluation of microstructural properties of dissimilar welded joins has been characterized through microhardness and optical microscopy measurements. The in- situ experimental set up was commissioned and dissimilar welded joints tested at 545 oC with a constant stress of 278.71MPafor a period of 300 h under inert atmosphere. Whereas, a cylindrical indenter (i.e., 1.1 mm dia.) had used with special arrangement with in connected LVDT and load cell indicator frequently monitor creep data under constant load and temperature. Since, impression creep testing is the gradual displacement as a function of time of a cylindrical punch under constant load measured. The punch penetration rate or impression velocity is controlled by the time dependence of the movement of mass from under the punch, which can directly monitor the creep properties of a localized zone of material below the punch. The ideology has been differentiated between conventional creep with impression creep features of dissimilar joints such as austenitic to ferritic weldment under compression with axial action. The dissimilar weldment has been naturally heterogenetic properties especially HAZ region discrepancy evaluated through impression creep testing. This article mainly focus on evaluated steady state creep rate of weldment under Knoop hardness measurement and microstructural variation during cast and post weld heat treatment conditions. It is also mentioned that both the weld and HAZ lower creep resistance than the base metal.