Effect of the Cooling Rate from the Temperatures of β-Range on the Structure and Properties of Alloys of the Ti – Cr System

• Published in: Metal science and heat treatment Vol. 64; no. 7-8; pp. 389 - 396
• Main Authors: Kollerov, M. Yu, Afonina, M. B., Zaynetdinova, G. T.
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.11.2022; Springer Nature B.V
• Subjects: Alloying elements; Characterization and Evaluation of Materials; Chemical composition; Chemistry and Materials Science; Chromium; Classical Mechanics; Cooling; Cooling rate; Diffusion; Engineering Thermodynamics; Heat and Mass Transfer; High temperature; Materials Science; Metallic Materials; Phase composition; Phase transitions; Rockwell hardness; Titanium; Titanium and Titanium Alloys; cooling rate; phase composition; anisothermal transformation; titanium alloys; structure; martensite
• ISSN: 0026-0673; 1573-8973
• DOI: 10.1007/s11041-022-00818-6

The effect of the content of chromium (from 2 to 20%) and of the rate of cooling in different media from β-range temperatures on the phase composition, structure and hardness of alloys of the Ti – Cr system is studied. The temperatures of the start of phase transformations and the Rockwell hardness of the alloys are determined. Metallographic, phase, and x-ray diffraction analyses are performed. It is shown that the critical cooling rate, which corresponds to a change in the mechanism of decomposition of the high-temperature β-phase from a martensitic one to a mixed one involving elements of diffusion-free and diffusion transformations and a dominantly diffusion one responsible for the equilibrium state of the alloy, decrease with increase of the concentration of the alloying element. The results of the study are generalized in the form of a “phase composition – chemical composition – cooling rate” diagram for alloys of the Ti – Cr system.