DEGRADATION OF 0.5Cr-0.5Mo-0.25V STEEL MICROSTRUCTURE DURING EXPLOITATION
Journal Title: Materials Engineering - Materialove inzinierstvo (MEMI) - Year 2011, Vol 18, Issue 2
Abstract
Degradation of 0.5Mo-0.5Cr-0.25V material after long-term high-temperature service has been studied by means of microstructure and mechanical properties analysis. Samples were taken from the pipeline with steam leaking found after almost 200,000 h service at 565 °C. The microstructure and properties have been compared with similar materials at similar exposure conditions without any signs of the rupture. Highly tempered ferrite contains secondary particles of MC, M2C and a kind of Cr-rich carbide (M23C6 and/or M7C3) in all materials studied. The difference have been found in the values of hardness. Fractures of samples after the impact test at various temperatures with typical embrittled features are also described. Analysis of the material service history like warm and cold starts-up, conditions of thermal and mechanical fatigue, together with microstruc¬ture and mechanical properties lead to the conclusion that the material was overtempered. The exhaustion of material deformationability resulted in the rupture-leakage of a component in the place of highest stresses.
Authors and Affiliations
Anna Výrostková, Ján Kepič, Roman Macko, Viera Homolová
Keywords
Related Articles
- EP ID EP102915
- DOI -
- Views 134
- Downloads 0
MICROSTRUCTURE AND MECHANICAL PROPERTIES DEGRADATION OF CrMo CREEP RESISTANT STEEL OPERATING UNDER CREEP CONDITIONS
In this contribution microstructure degradation of a steam tube is analysed. The tube is made of CrMo creep resistant steel and was in service under creep conditions at temperature 530°C and calculated stress level in th...
CORROSION OF COPPER PIPES JOINTS IN SIMULATED OPERATING CONDITIONS
Joining of copper pipes used for liquid media transport are made as demountable and fixation joints. This work deals with corrosion behavior of the joints made by soft soldering, hard soldering and fitting. Corrosion pro...
34CrMo4 steel resistance against the SSC after controlled cooling process
The sulphide stress cracking corrosion resistance of 34CrMo4 steel after the accelerated cooling process under the Ar3 temperature was investigated. Two modes of heat treatment were applied to achieve homogeneous microst...
Study of the influence of agricultural waste on the porosity of clay brick
This paper deals with the influence of two organic residues on the porosity of clay bricks. The insulation capacity of the brick increases with increasing the porosity. Combustible organic additions are often used to for...
Static and dynamic tensile characteristics of DP600 steel sheets
Dynamic tensile testing of sheet steels is becoming more important. Experimental dynamic tensile technique is depending on the strain rate. Each serves for a specific range of strain rates and provides specific type of i...