Effect of pressing temperature on microstructure and tensile behavior of low carbon steels processed by equal channel angular pressing

• Published in: Materials science & engineering. A, Structural materials : properties, microstructure and processing Structural materials : properties, microstructure and processing, 2002-02, Vol.325 (1-2), p.31-37
• Main Authors: DONG HYNK SHIN, PAK, Jong-Jin, YOUNG KUK KIM, PARK, Kyung-Tae, KIM, Yong-Seog
• Format: Article
• Language: English
• Subjects: Applied sciences; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Materials science; Metals. Metallurgy; Other heat and thermomechanical treatments; Physics; Treatment of materials and its effects on microstructure and properties
• ISSN: 0921-5093; 1873-4936
• DOI: 10.1016/S0921-5093(01)01415-0

Two grades of low carbon steels, one containing vanadium and the other without vanadium, were subjected to equal channel angular (ECA) pressing at a temperature range of 623-873 K. For steel without vanadium, the ECA pressing at 623 K resulted in ultrafine (approx 0.3 micron) ferrite grains with high angle boundaries. At higher pressing temperature, coarser grains with low angle boundaries were formed, which indicates that the recovery occurs at a significant rate during the pressing. For the steel containing vanadium, submicrometer order ferrite grains and high dislocation density were preserved up to a pressing temperature of 873 K. The enhanced thermal stability of the steel containing vanadium was attributed to its peculiar microstructure consisting of fine ferrite grains with uniformly distributed nanosized cementite particles. In addition, the tensile behaviors of the ECA pressed steels were characterized and discussed based on the microstructure.