Application of-140 degrees C Sub-Zero Treatment For Cr-V Ledeburitic Steel Service Performance Improvement

0504335 - ÚFM 2020 RIV US eng J - Journal Article
Jurči, P. - Ďurica, J. - Dlouhý, Ivo - Horník, J. - Planieta, R. - Kraľovič, D.
Application of-140 degrees C Sub-Zero Treatment For Cr-V Ledeburitic Steel Service Performance Improvement.
Metallurgical and Materials Transactions A. 50A, č. 5 (2019), s. 2413-2434. ISSN 1073-5623. E-ISSN 1543-1940
Institutional support: RVO:68081723
Keywords : Tool steels * Fracture-toughness * Wear-resistance
OECD category: Materials engineering
Impact factor: 2.050, year: 2019
Method of publishing: Limited access
https://link.springer.com/article/10.1007%2Fs11661-019-05180-6

The effect of -140 degrees C, 17-hour sub-zero treatment and subsequent tempering on the hardness, flexural strength, and fracture toughness of Cr-V ledeburitic steel was investigated. The main purpose was to highlight the role of microstructural alterations, such as a decrease of the retained austenite content, the quantitative parameters of carbide distributions, or others, due to applied treatments. Compared to conventional treatments, the applied sub-zero treatment improves the hardness of the material significantly within the whole range of tempering temperatures used. The hardness enhancement is in the range from 197 to 137 HV10 for tempering at 170 degrees C to 450 degrees C. The flexural strength is slightly improved at low tempering conditions up to 170 degrees C, while there is almost no effect of the sub-zero treatment on flexural strength for higher tempering temperatures. The fracture toughness is substantially improved (by about 3 MPam(1/2)) in the untempered state as well as after high-temperature tempering. The fracture toughness is slightly worsened, by about 0.15 to 1 MPam(1/2), within the 170 degrees C to 450 degrees C range of tempering temperatures. These changes in fracture toughness are reached with a significant increase of hardness. This steel performance is associated with enhanced fracture surface roughness and an increased ductile microvoid coalescence micromechanism presence in fracture surfaces. The results also show that treatment at -140 degrees C leads to a greater enhancement of the complex of mechanical properties than can be obtained by soaking the samples in liquid nitrogen.
Permanent Link: http://hdl.handle.net/11104/0296054