| Title |
Effect of Co Addition on Tensile Properties in Secondary Hardening Co-Ni Alloy Steels |
| Authors |
권훈(Hoon Kwon); 이건배(Kon Bae Lee); 심호섭(Ho Seop Sim); 조기섭(Ki Sub Cho); 양형렬(Hyung Ryul Yang) |
| ISSN |
1738-8228(ISSN), 2288-8241(eISSN) |
| Keywords |
ultrahigh strength steel; Co-Ni steel; secondary hardening; tensile properties; severe deformation |
| Abstract |
The effect of Co additions on tensile properties in the secondary hardening Co-Ni alloy steels has been studied in as-quenched and aged conditions. Three kinds of (5-13)Co-11Ni steels, containing Mo and Cr, were severely multipass-rolled in unrecrystallized region and followed by accelerated cooling. In as-quenched condition, an increase in yield strength and a decrease in uniform elongation with an increase in Co content are closely related with a decrease in the amount of retained austenite. In peak-aged condition, yield and tensile strengths and peak hardness increased with the increase of Co content, but peak time remained around 5 hours. Thus, Co additions would enhance the nucleation of fine M2C carbides rather than their growth. |