Influence of Vanadium on the Microstructure and Mechanical Properties of Medium-Carbon Steels for Wheels

Metals

Qilong Yong¹  Caifu Yang¹  Shitong Zhou¹  Zhaodong Li¹  Guobiao Lin²  Pengfei Wang² 

[1] Department of Structural Steels, Central Iron and Steel Research Institute, Beijing 100081, China;School of Materials Science and Engineering, University of Science and Technology, Beijing 100083, China;

关键词: medium-carbon steel;    grain refinement;    precipitation strengthening;    strength and toughness;   

DOI  :  10.3390/met8120978

来源: DOAJ

【 摘 要 】

Steels used for high-speed train wheels require a combination of high strength, toughness, and wear resistance. In 0.54% C-0.9% Si wheel steel, the addition of 0.075 or 0.12 wt % V can refine grains and increase the ferrite content and toughness, although the influence on the microstructure and toughness is complex and poorly understood. We investigated the effect of 0.03, 0.12, and 0.23 wt % V on the microstructure and mechanical properties of medium-carbon steels (0.54% C-0.9% Si) for train wheels. As the V content increased, the precipitation strengthening increased, whereas the grain refinement initially increased, and then it remained unchanged. The increase in strength and hardness was mainly due to V(C,N) precipitation strengthening. Increasing the V content to 0.12 wt % refined the austenite grain size and pearlite block size, and increased the density of high-angle ferrite boundaries and ferrite volume fraction. The grain refinement improved the impact toughness. However, the impact toughness then reduced as the V content was increased to 0.23 wt %, because grain refinement did not further increase, whereas precipitation strengthening and ferrite hardening occurred.

【 授权许可】

Unknown