In-situ quantification and density functional theory elucidation of phase transformation in carbon steel during quenching and partitioning

Wang, Shubo; Kistanov, Andrey A.; King, Graham; Ghosh, Sumit; Singh, Harishchandra; Pallaspuro, Sakari; Rahemtulla, Al; Somani, Mahesh C.; Kömi, Jukka; Cao, Wei; Huttula, Marko

doi:10.1016/j.actamat.2021.117361

Cited by 14 publications

(3 citation statements)

References 72 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Meeting the demands for lightweight construction and safety requires advanced high-strength steel with a combination of exceptional strength and ductility. Quenching and partitioning (Q&P) steel [ 3 , 4 , 5 , 6 ], as a third-generation advanced high-strength steel, possesses the ability to fulfill both requirements concurrently [ 7 ]. The Q&P process [ 3 , 5 , 8 , 9 ] involves either partial or full austenitization, followed by quenching to a temperature between the martensite start temperature (Ms) and martensite finish temperature (Mf), in order to obtain a specific fraction of martensite.…”

Section: Introductionmentioning

confidence: 99%

Effect of Cold Rolling Reduction Rate on the Microstructure and Properties of Q&P Steel with a Ferrite-Pearlite Initial Structure

Wang,

Chen,

Yang

et al. 2023

Materials

View full text Add to dashboard Cite

Quenching and partitioning (Q&P) steel has garnered attention as a promising third-generation automotive steel. While the conventional production (CP) method for Q&P steel involves a significant cumulative cold rolling reduction rate (CRRR) of 60–70%, the thin slab casting and rolling (TSCR) process has emerged as a potential alternative to reduce or eliminate the need for cold rolling, characterized with a streamline production chain, high-energy efficiency, mitigated CO2 emission and economical cost. However, the effect of the CRRR on the microstructure and properties of Q&P steel with an initial ferrite-pearlite microstructure has been overlooked, preventing the extensive application of TSCR in producing Q&P steel. In this work, investigations involving different degrees of CRRRs reveal a direct relationship between increased reduction and decreased yield strength and plasticity. Notably, changes in the microstructure were observed, including reduced size and proportion of martensite blocks, increased ferrite proportion and decreased retained austenite content. The decrease in yield strength was primarily attributed to the increased proportion of the softer ferrite phase, while the reduction in plasticity was primarily linked to the decrease in retained austenite content. This study provides valuable insights for optimizing the TSCR process of Q&P steel, facilitating its wider adoption in the automotive sector.

show abstract

Section: Introductionmentioning

confidence: 99%

Effect of Cold Rolling Reduction Rate on the Microstructure and Properties of Q&P Steel with a Ferrite-Pearlite Initial Structure

Wang,

Chen,

Yang

et al. 2023

Materials

View full text Add to dashboard Cite

show abstract

“…Past research on steels has shown that the use of in-situ approaches to gather time-resolved information is useful [ 17 , 18 , 19 , 20 , 21 , 22 ]. Furthermore, recent studies on microstructural development during Q&P treatment suggest that in-situ HEXRD is among the best approaches for studying carbon partitioning [ 7 , 23 , 24 , 25 , 26 , 27 , 28 , 29 ].…”

Section: Introductionmentioning

confidence: 99%

Kinetics of Carbon Enrichment in Austenite during Partitioning Stage Studied via In-Situ Synchrotron XRD

et al. 2023

View full text Add to dashboard Cite

The present study reveals the microstructural evolution and corresponding mechanisms occurring during different stages of quenching and partitioning (Q&P) conducted on 0.6C-1.5Si steel using in-situ High Energy X-Ray Diffraction (HEXRD) and high-resolution dilatometry methods. The results support that the symmetry of ferrite is not cubic when first formed since it is fully supersaturated with carbon at the early stages of partitioning. Moreover, by increasing partitioning temperature, the dominant carbon source for austenite enrichment changes from ongoing bainitic ferrite transformation during the partitioning stage to initial martensite formed in the quenching stage. At low partitioning temperatures, a bimodal distribution of low- and high-carbon austenite, 0.6 and 1.9 wt.% carbon, is detected. At higher temperatures, a better distribution of carbon occurs, approaching full homogenization. An initial martensite content of around 11.5 wt.% after partitioning at 280 °C via bainitic ferrite transformation results in higher carbon enrichment of austenite and increased retained austenite amount by approximately 4% in comparison with partitioning at 500 °C. In comparison with austempering heat treatment with no prior martensite, the presence of initial martensite in the Q&P microstructure accelerates the subsequent low-temperature bainitic transformation.

show abstract

“…Besides C partitioning, a number of additional microstructural processes, including austenite decomposition into bainite or isothermal martensite, tempering of martensite, clustering of C atoms, and carbide precipitation, also became apparent during the Q&P processing. [8][9][10] Final cooling sometimes leads to the formation of a fraction of untempered high-C martensite from the carbon-enriched austenite depending on its stability. In general, a fraction of C atoms available for partitioning is often trapped in the martensite due to clustering or locking at the dislocation walls or other defects or otherwise participate in carbide formation.…”

Section: Introductionmentioning

confidence: 99%

A combined 3D-atomic/nanoscale comprehension and ab initio computation of iron carbide structures tailored in Q&P steels via Si alloying

et al. 2023

Self Cite

View full text Add to dashboard Cite

show abstract

In-situ quantification and density functional theory elucidation of phase transformation in carbon steel during quenching and partitioning

Cited by 14 publications

References 72 publications

Effect of Cold Rolling Reduction Rate on the Microstructure and Properties of Q&P Steel with a Ferrite-Pearlite Initial Structure

Effect of Cold Rolling Reduction Rate on the Microstructure and Properties of Q&P Steel with a Ferrite-Pearlite Initial Structure

Kinetics of Carbon Enrichment in Austenite during Partitioning Stage Studied via In-Situ Synchrotron XRD

A combined 3D-atomic/nanoscale comprehension and ab initio computation of iron carbide structures tailored in Q&P steels via Si alloying

Contact Info

Product

Resources

About