Strength–ductility trade-off dilemma is acute in materials science, especially for ultrahigh-strength steels. The improvement of toughness requires careful tuning of grains and precipitates. Thermal cyclic treatment and annealing before quenching are two effective ways of microstructural refinement for steels. However, a combination of the two methods has never been studied. Complex alloy carbides form in the process of annealing, but their effects on grain refinement in the subsequent quenching are unclear. Here, a systematic comparison of microstructure and mechanical properties is established between a thermal cyclic treatment with annealing (CHT) and traditional quench-temper treatment (QT). The results indicate that the CHT treatment leads to the coarsening of alloy carbides and subgrains, and the decrease in strength and toughness.
LeeKOHongSKKangYK, et al.Grain refinement in bearing steels using a double-quenching heat-treatment process. Int J Automot Technol2009; 10: 697–702.
4.
Khani SanijMHGhasemi BanadkoukiSSMashreghiAR,et al.The effect of single and double quenching and tempering heat treatments on the microstructure and mechanical properties of AISI 4140 steel. Mater Des2012; 42: 339–346.
5.
LiZMiyamotoGYangZ,et al.Nucleation of austenite from pearlitic structure in an Fe–0.6C–1Cr alloy. Scr Mater2009; 60: 485–488.
6.
LiZXLiCSKimSH,et al.Influence of initial pearlite morphology on the microstructure evolution during heat treatment of 1.0C–1.5Cr steel. Met Mater Int2019; 25: 9–17.
7.
SongYYLiXYRongLJ, et al.Reversed austenite in 0Cr13Ni4Mo martensitic stainless steels. Mater Chem Phys2014; 143: 728–734.
8.
SchnitzerRRadisRNöhrerM, et al.Reverted austenite in PH 13-8 Mo maraging steels. Mater Chem Phys2010; 122: 138–145.
9.
XiongWSongRHuoW, et al.Microstructure characteristics and impact fracture mechanisms of Nb and V–Ti micro-alloyed offshore platform steels. Vacuum2022; 195: 110709.
10.
ZhangYLiXLiuY, et al.Study of the kinetics of austenite grain growth by dynamic Ti-rich and Nb-rich carbonitride dissolution in HSLA steel: in-situ observation and modeling. Mater Charact2020; 169: 110612.
11.
XiongZTimokhinaIPerelomaE. Clustering, nano-scale precipitation and strengthening of steels. Prog Mater Sci2021; 118: 100764.
12.
BakerTN. Processes, microstructure and properties of vanadium microalloyed steels. Mater Sci Technol2009; 25: 1083–1107.
13.
BhadeshiaHKDH. Solution to the Bagaryatskii and Isaichev ferrite–cementite orientation relationship problem. Mater Sci Technol2018; 34: 1666–1668.
14.
MoritoSTanakaHKonishiR, et al.The morphology and crystallography of lath martensite in Fe-C alloys. Acta Mater2003; 51: 1789–1799.
15.
BabuSSSpechtEDDavidSA, et al.In-situ observations of lattice parameter fluctuations in austenite and transformation to bainite. Metall Mater Trans A2005; 36: 3281–3289.
16.
TakeuchiAInoueA. Classification of bulk metallic glasses by atomic size difference, heat of mixing and period of constituent elements and its application to characterization of the main alloying element. Mater Trans2005; 46: 2817–2829.
17.
LeiXWLiDYZhangXH,et al.Effect of solid solution elements on solubility products of carbides and nitrides in austenite: thermodynamic calculations. Metall Mater Trans A Phys Metall Mater Sci2019; 50: 4445–4461.
18.
XiaodongLSolbergJKGjengedalR,et al.An expression for solubility product of complex carbonitrides in multicomponent microalloyed austenite. Scr Metall Mater1994; 31: 1607–1612.
19.
PavlinaEJSpeerJGVan TyneCJ. Equilibrium solubility products of molybdenum carbide and tungsten carbide in iron. Scr Mater2012; 66: 243–246.
20.
RobsonJD. Modelling the overlap of nucleation, growth and coarsening during precipitation. Acta Mater2004; 52: 4669–4676.
