Microalloying and precipitation in Cr-V rail steels
| Autor: | D. E. Parsons, T. F. Malis, J. D. Boyd |
|---|---|
| Rok vydání: | 1984 |
| Předmět: |
Materials science
Precipitation (chemistry) Cementite Mechanical Engineering Metallurgy Metals and Alloys General Engineering chemistry.chemical_element Vanadium Nitrogen chemistry.chemical_compound chemistry Mechanics of Materials Aluminium Pearlite Saturation (chemistry) Strengthening mechanisms of materials |
| Zdroj: | Journal of Heat Treating. 3:213-219 |
| ISSN: | 0190-9177 |
| DOI: | 10.1007/bf02833263 |
| Popis: | A study of alloying effects in Cr-V rail steels has been carried out to determine the microstructural strengthening mechanisms. The laboratory steels investigated were based on the commercial 1 pct Cr rail steel chemistry (0.75C−0.8Mn−1 .25Cr−0.30Si) and represented two levels of nitrogen (nominally 0.007 and 0.015 wt pct) and two types of deoxidation practice. It is found that vanadium microalloying produces a yield stress increment of approximately 90 MPa for low-nitrogen steels and 140 M Pa for highnitrogen steels. This strengthening effect appears to saturate at or below 0.15 wt pct vanadium, with no further strength increase for higher vanadium concentration. The hardness and UTS exhibit the same variation with vanadium content as the yield stress. There is no consistent effect of aluminum content (deoxidation practice). Several distinct precipitate morphologies, a wide range of precipitate sizes, and a nonhomogeneous distribution of precipitates are observed. There is also significant partitioning of V, Cr, and Mn to cementite. It is suggested that an increase in the amount of coarse, austenitenucleated V(C,N) and possibly other coarse precipitate modes is responsible for the saturation of the vanadium strengthening effect. |
| Databáze: | OpenAIRE |
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