HOT COMPRESSION TEST OF 9 Cr-1 Mo STEEL – NUMERICAL SIMULATION

Abstract

This paper is focused on the evaluation of formability of heat resistant steel type 9Cr-1Mo by laboratory numerical simulationhot compression test confirmed by laboratory hot compression test. The 9Cr-1Mo steel represents modern 9%Cr tempered martensitic steel for high temperature applications in advanced thermal power plants. Numerical simulations were computed in software Deform 3D for five proposed sample shapes. On the base of normalized Cockcroft-Latham criterion (nCL), indicating the material damage during deformation, the sample type "tapered roller with four axial notches" was found to be the most suitable for hot workability evaluation. On base of simulations, it is also evaluated the temperature range of the workability of 9Cr-1Mo. The interval of good workability according to the nCL criteria is in the temperature range from 650 to 950 °C.

The influence of isothermal ageing and subsequent hydrogen charging at room temperature on local mechanical properties and fracture characteristics of martensitic-bainitic weldments for power engineering

“…Besides alternative energy sources, a possible way allowing gradual increase in energy production with simultaneous decrease of CO 2 emissions is based on the increasing of steam-cycle thermal efficiency of modern power generating plants. This issue represents the main driving force for new material developments aiming for obtaining higher operating conditions in so-called "ultra supercritical" boilers [1][2][3]. Since the power plant boilers consist of several steam circuits heated up to different service temperatures, a wide range of creep-resistant steels is used for their construction.…”

Hot Compression Test of Heat Resistant Steel

“…Used material properties in numerical simulation are from Deform 2D/3D material database. The final sample shape tapered type with four axial notches has been identified as the most suitable form of the sample given the maximum value in the nCL criteria compared to other types of samples according to the literature [13]. In fact, for physical simulations the shape of sample was brought into line with the requirement of the testing machine, Fig.…”

“…The sampling shape was designed according to the results of the mathematical simulations [13][14][15]. Cracks formed in the notches are assessed.…”

Theoretical-Experimental Possibillities of Microstructure Quantification of Dispersion Strengthened Materials

“…The research proceeds in several directions the most important of which are new metallic alloys, ceramics, polymers, composites and amorphous materials. The composite materials with metallic, plastic and ceramic bases have already found their application in the machine industry, but their wider use is still limited by insufficient automation on their production resulting in their cost and by the need to elaborate new designs and techniques adapted for a better understanding and influencing of their properties, [1][2][3][4][5][6][7][8]. The mechanism of dispersion strengthening is based on the presence of a low volume fraction of fine secondary particles in the metal matrix, [9 -11].…”