engleski

Fractography Analysis of Low Alloyed Steel

High strength low alloyed steel (HSLA) are group of low carbon steel alloyed with a small contents of elements (Mo, Ti, V and Nb) in order to obtain high yield strength. Basic properties of the steel are: high strength, resistance to corrosion, good weldability and acceptable price. These steels are used for different applications: line pipe, off shore, tank for liquid natural gas etc. In this work, results of NIOMOL 490 K fine-grain structural steel with high yield strength and acceptable chemical composition, for welding without prior heating, were presented. Fractography and metallography analysis were carried out. After different heat treatment procedures microstructure of the steel was changed. It was found three areas of fracture surface, from ductile to brittle and mixed fracture surface depending on values of Charpy impact energy.

high strength low alloyed steel, fractography analysis, microstructure, mechanical properties

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