| Title |
Transformations : Ultrasonic Evaluation of Spheroidization of Cementite in Medium Carbon Steel |
| Authors |
김준수(J . S . Kim),변재원(Jai Won Byeon),권소인(S . I . Kwun),박은수(U . S . Park) |
| ISSN |
1738-8228(ISSN), 2288-8241(eISSN) |
| Abstract |
An attempt was made to evaluate the change of microstructures and mechanical properties with increasing spheroidizing time in a cold heading steel, containing proeutectoid ferrite and pearlite, by the ultrasonic attenuation and velocity measurements. Ultrasonic velocity was not sensitive to the microstructural changes, resulting from spheroidization heat treatment to produce various mean aspect ratio, mean equivalent size and number of cementite particles per unit area and ferrite grain size. Ultrasonic attenuation was initially decreased and then increased with increasing spheroidizing time. A good correlation between ultrasonic attenuation coefficient and mechanical properties such as hardness and tensile strength was found. |