Abstract
Abstract An influence of a decreased Cr content on the microstructure of the highly alloyed Cr-Ni cast steel, duplex type, melted under laboratory conditions, was characterized in the paper. The microstructure investigations were performed in the initial state and after the heat treatment (solution annealing) at 1060°C as well as the phase transformation kinetics at continuous cooling was measured. The wear resistance of the investigated cast steel was tested and compared with the 24%Cr-5%Ni-2.5%Mo cast steel. The Cr content decrease, in ferritic-austenitic cast steels (duplex), from 24-26%Cr to 18% leads to the changes of the castings microstructure and eliminating of a brittle σ phase. In dependence of the casting cooling rate, apart from ferrite and austenite, also fine martensite precipitates occur in the casting structure. It was shown that the investigated cast steel is characterised by a slightly lower wear resistance than the typical cast steel duplex grades.
Highlights
Corrosion resistant Cr-Ni cast steels are necessary materials applied for castings operating in several industry sectors [1, 2]
Taking into consideration high costs of castings from Cr-Ni cast steels, investigations were undertaken to examine the microstructure and abrasive wear resistance of cast steels characterised by a decreased Cr content in relation to the typical duplex steel of the second generation, and by the chemical composition corresponding to the duplex steel grade of the first generation 3RE60 (S31500; EN 1.4417) [5, 13]
At a higher magnification precipitates of another phase are seen in austenite areas. It is specially visible in microstructure images recorded by the scanning microscope (Fig.2)
Summary
Corrosion resistant Cr-Ni cast steels are necessary materials applied for castings operating in several industry sectors [1, 2] Within this group are cast steels of a ferritic-austenitic structure containing approximately: 24-26%Cr, 4-6%Ni and 2-3%Mo characterised by a high PREN coefficient, good corrosive resistance in environment containing chloride ions, Cl- , and a creep limit twice as high as the one of traditional grades of austenitic cast steel [3,4,5,6,7,8,9]. Taking into consideration high costs of castings from Cr-Ni cast steels, investigations were undertaken to examine the microstructure and abrasive wear resistance of cast steels characterised by a decreased Cr content in relation to the typical duplex steel of the second generation, and by the chemical composition corresponding to the duplex steel grade of the first generation 3RE60 (S31500; EN 1.4417) [5, 13]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
