Lotus-type porous carbon steel (AISI1018) with aligned cylindrical pores was fabricated by continuous casting method in a mixture gas atmosphere (PN 2=0.8MPa, PAr=1.7MPa). Compressive yield strength of the nonporous and the lotus carbon steels was measured in the direction parallel to the transference direction. The compressive stress of the lotus carbon steel is lower than that of the nonporous carbon steel because of the existence of pores. The specific compressive yield strength (σ0.2/ρ) of as-cast lotus carbon steel is higher than that of as-cast nonporous carbon steel, which is due to the solid solution hardening of nitrogen. Although the microstructure of carbon steel changes from Widmannstätten to homogeneous ferrite and pearlite by normalizing, the yield strength does not change significantly by normalizing. The microstructure of lotus carbon steel changes from Widmannstätten to martensite by quenching so that the yield strength increases significantly.
ASJC Scopus subject areas
- Physics and Astronomy(all)