Metallurgical Engineering

Metallurgical Engineering

Investigating the effect of temperature and time of intercritical heat treatment on the microstructure and tensile properties of Al-rich steel

Document Type : Research Paper

Authors
Alireza Kheradmand 1
Alireza Kolahi 2
Yahya Palizdar 3
1 Master's student in materials engineering, Materials and Energy Research center, Karaj, Iran
2 Nanotechnology and Advanced Materials Department, Materials and Energy Research center, Karaj, Iran.
3 Materials and Energy research center (MERC)
10.22076/me.2024.2015131.1394
Abstract
The present study involved the casting and hot-rolling of steel with a chemical composition of Fe-0.25C-0.33Si-1.05Mn-4.56Al. Subsequently, heat treatment was applied at various temperatures and durations to achieve the necessary material characteristics. Initially, all of the specimens underwent austenitization at a temperature of 820 ℃, which is the annealing temperature corresponding to the midpoint of the critical range. This process lasted for a duration of 600 seconds. Subsequently, the specimens were subjected to quenching in oil at a temperature of 150 ℃, and this temperature was maintained for a period of 20 seconds. Finally, the specimens were immersed in a salt bath. The mixture, composed of equal parts NaNO3 and KNO3, was subjected to transfer and partitioning processes at temperatures of 330 and 450 ℃, and for durations of 1000 and 1800 seconds. Subsequently, the mixture was rapidly cooled by immersion in water. The microstructural composition of steel after to heat treatment encompasses the presence of δ-ferrite, α-ferrite, retained austenite, and a minor quantity of martensite. The volume fraction of the surviving austenite is shown to grow as the temperature and partitioning time are elevated. This can be attributed to the heightened driving force and increased likelihood of carbon diffusion. The sample that underwent partitioning at a temperature of 450 ℃ for a duration of 1800 seconds yielded the optimal combination of strength and elongation, resulting in a product value of 41600MPa%. The provided specimen exhibits a tensile strength of 1300 MPa and experiences a 32% elongation.
Keywords
Al-rich steel
heat treatment
&‌‌‌delta
-ferrite
retained austenite
quenching and partitioning
1.        De Cooman BC, Estrin Y, Kim SK. Twinning-induced plasticity (TWIP) steels. Acta Mater 2018; 142: 283–362.
2.        Chatterjee S, Murugananth M, Bhadeshia H. δ TRIP steel. Mater Sci Technol 2007; 23: 819–827.
3.        Tasan CC, Diehl M, Yan D, et al. An overview of dual-phase steels: advances in microstructure-oriented processing and micromechanically guided design. Annu Rev Mater Res 2015; 45: 391–431.
4.        Fonstein N. Advanced high strength sheet steels. Springer, 2015.
5.        Avishan B, Yazdani S, Nedjad SH. Toughness variations in nanostructured bainitic steels. Mater Sci Eng A 2012; 548: 106–111.
6.        Kwon O, Lee KY, Kim GS, et al. New trends in advanced high strength steel developments for automotive application. In: Materials Science Forum. Trans Tech Publ, 2010, pp. 136–141.
7.        San Martín D, Palizdar Y, García-Mateo C, et al. Influence of aluminum alloying and heating rate on austenite formation in low carbon-manganese steels. Metall Mater Trans A 2011; 42: 2591–2608.
8.        Yi HL. Review on δ-transformation-induced plasticity (TRIP) steels with low density: the concept and current progress. Jom 2014; 66: 1759–1769.
9.        Rajan T V, Sharma CP, Sharma A. Heat treatment: principles and techniques. PHI Learning Pvt. Ltd., 2023.
10.      Nyyssönen T, Oja O, Jussila P, et al. Quenching and partitioning of multiphase aluminum-added steels. Metals (Basel) 2019; 9: 373.
11.      Pourfarokh A, Jafarian HR, Eivani AR, et al. Regulating tensile properties through bainitic transformation temperature in a hot-rolled δ-TRIP steel. Mater Sci Technol 2020; 36: 223–232.
12.      Matlock DK, Speer JG. Third generation of AHSS: microstructure design concepts. In: Microstructure and Texture in Steels: and Other Materials. Springer, 2009, pp. 185–205.
13.      Bhadeshia HKDH, Christian JW. Bainite in steels. Metall Trans A 1990; 21: 767–797.
14.      Babasafari Z, Pan A V, Pahlevani F, et al. Effect of silicon and partitioning temperature on the microstructure and mechanical properties of high-carbon steel in a quenching and partitioning heat treatment. J Mater Sci 2021; 56: 15423–15440.
15.      Zhao Y, Yan Q, Chen L, et al. Effect of isothermal temperature on microstructure and mechanical properties of high Al–low Si TRIP steel. Acta Metall Sin (English Lett 2014; 27: 389–394.
16.      Sui G, Charles EA, Congleton J. The effect of delta-ferrite content on the stress corrosion cracking of austenitic stainless steels in a sulphate solution. Corros Sci 1996; 38: 687–703.
17.      Xiong XC, Chen B, Huang MX, et al. The effect of morphology on the stability of retained austenite in a quenched and partitioned steel. Scr Mater 2013; 68: 321–324.
18.      Shen YF, Liu YD, Sun X, et al. Improved ductility of a transformation-induced-plasticity steel by nanoscale austenite lamellae. Mater Sci Eng A 2013; 583: 1–10.
19.      Zhang M-X, Kelly PM, Bekessy LK, et al. Determination of retained austenite using an X-ray texture goniometer. Mater Charact 2000; 45: 39–49.
20.      Yang MX, Yuan FP, Xie QG, et al. Strain hardening in Fe–16Mn–10Al–0.86 C–5Ni high specific strength steel. In: Heterostructured Materials. Jenny Stanford Publishing, 2021, pp. 721–747.
21.      Wang C, Zhang Y, Cao W, et al. Austenite/martensite structure and corresponding ultrahigh strength and high ductility of steels processed by Q&P techniques. Sci China Technol Sci 2012; 55: 1844–1851.
22.      Jirková H, Kučerová L, Mašek B. Effect of Quenching and Partitioning Temperatures in the QP Process on the Properties of AHSS with Various Amounts of Manganese and Silicon. In: Materials Science Forum. Trans Tech Publ, 2012, pp. 2734–2739.
23.      Speer JG, Edmonds D V, Rizzo FC, et al. Partitioning of carbon from supersaturated plates of ferrite, with application to steel processing and fundamentals of the bainite transformation. Curr Opin Solid State Mater Sci 2004; 8: 219–237.
24.      Li HY, Lu XW, Wu XC, et al. Bainitic transformation during the two-step quenching and partitioning process in a medium carbon steel containing silicon. Mater Sci Eng A 2010; 527: 6255–6259.
25.      Kickinger C, Suppan C, Hebesberger T, et al. Microstructure and mechanical properties of partially ferritic Q&P steels. Mater Sci Eng A 2021; 815: 141296.
26.      Kantanen PK, Javaheri V, Somani MC, et al. Materials Characterization Effect of deformation and grain size on austenite decomposition during quenching and partitioning of ( high ) silicon ‑ aluminum steels. 171. Epub ahead of print 2021. DOI: 10.1016/j.matchar.2020.110793.
27.      Bhadeshia H. Driving force for martensitic transformation in steels. Met Sci 1981; 15: 175–177.
28.      Nyyssönen T, Peura P, De Moor E, et al. Crystallography and mechanical properties of intercritically annealed quench and partitioned high-aluminum steel. Mater Charact 2019; 148: 71–80.

  • Receive Date 07 November 2023
  • Revise Date 13 April 2024
  • Accept Date 09 June 2024