Next Article in Journal
A Brief Note on the Nix–Gao Strain Gradient Plasticity Theory
Previous Article in Journal
Influence of σ Phase on the Allotropic Transformation of the Matrix in Co-Re-Cr-Based Alloys with Ni Addition
Article Menu
Issue 9 (September) cover image

Export Article

Open AccessArticle
Metals 2018, 8(9), 707; https://doi.org/10.3390/met8090707

Simultaneously Enhanced Strength, Toughness and Ductility of Cast 40Cr Steels Strengthened by Trace Biphase TiCx-TiB2 Nanoparticles

1
State Key Laboratory of Automotive Simulation and Control, Jilin University, Renmin Street NO. 5988, Changchun 130025, China
2
Key Laboratory of Automobile Materials, Ministry of Education and Department of Materials Science and Engineering, Jilin University, Renmin Street NO. 5988, Changchun 130025, China
3
Qingdao Automotive Research Institute of Jilin University, Renmin Street NO. 5988, Changchun 130025, China
4
School of Materials Science and Engineering, Jiangsu University of Science and Technology, Zhenjiang 212003, China
*
Authors to whom correspondence should be addressed.
Received: 10 August 2018 / Revised: 2 September 2018 / Accepted: 4 September 2018 / Published: 9 September 2018
(This article belongs to the Special Issue Advances in Metal Composites and Processing Technologies)
Full-Text   |   PDF [3749 KB, uploaded 9 September 2018]   |  

Abstract

Simultaneously improving the strength, toughness, and ductility of cast steels has always been a difficult problem for researchers. Biphase TiCx-TiB2 nanoparticle-reinforced cast steels are prepared by adding in situ nanosized biphase TiCx-TiB2/Al master alloy during the casting process. The experimental results show that a series of significant changes take place in the microstructure of the steel: the ferrite-pearlite structure of the as-cast steels and the bainite structure of the steels after heat treatment are refined, the grain size is reduced, and the content of nanoparticles is increased. Promotion of nucleation and inhibition of dendrite growth by biphase TiCx-TiB2 nanoparticles leads to a refinement of the microstructure. The fine microstructure with evenly dispersed nanoparticles offers better properties [yield strength (1246 MPa), tensile strength (1469 MPa), fracture strain (9.4%), impact toughness (20.3 J/cm2) and hardness (41 HRC)] for the steel with 0.018 wt.% biphase TiCx-TiB2 nanoparticles, which are increased by 15.4%, 31.2%, 4.4%, 11.5%, and 7.9% compared with the 40Cr steels. The higher content of nanoparticles provides higher strengths and hardness of the steel but are detrimental to ductility. The improved properties may be attributed to fine grain strengthening and the pinning effect of nanosized carbide on dislocations and grain boundaries. Through this work, it is known that the method of adding trace (0.018 wt.%) biphase TiCx-TiB2 nanoparticles during casting process can simultaneously improve the strength, toughness, as well as ductility of the cast steel. View Full-Text
Keywords: TiCx-TiB2 nanoparticles; grain refinement; mechanical property; strengthening mechanism TiCx-TiB2 nanoparticles; grain refinement; mechanical property; strengthening mechanism
Figures

Figure 1

This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. (CC BY 4.0).
SciFeed

Share & Cite This Article

MDPI and ACS Style

Li, C.-L.; Qiu, F.; Chang, F.; Zhao, X.-M.; Geng, R.; Yang, H.-Y.; Zhao, Q.-L.; Jiang, Q.-C. Simultaneously Enhanced Strength, Toughness and Ductility of Cast 40Cr Steels Strengthened by Trace Biphase TiCx-TiB2 Nanoparticles. Metals 2018, 8, 707.

Show more citation formats Show less citations formats

Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Related Articles

Article Metrics

Article Access Statistics

1

Comments

[Return to top]
Metals EISSN 2075-4701 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top