Abstract
The objectives of this study are (1) to investigate the microstructural changes in structural steels that are exposed to fire accidents; and (2) to understand their influence on post-fire mechanical properties. Specifically, three structural steels—ASTM A36, ASTM A572, and ASTM A992—are employed, and three post-fire mechanical properties—yield strength, ultimate tensile strength, and ductility—are determined. Structural steel specimens are subjected to high temperatures ranging from 500°C to 1,000°C for 1 h and are subsequently air-cooled. Post-fire mechanical properties of air-cooled specimens are determined using uniaxial tension tests. Metallographic specimens are prepared, and microstructural analysis is carried out. Changes in metallurgical phases are tracked, and the grain sizes of the corresponding metallurgical phases are evaluated as a function of exposed temperature. By observing the post-fire mechanical properties of steels along with the microstructural analysis, an increase in ferrite volume fraction and ferrite grain size clearly leads to a reduction in both the post-fire yield strength and ultimate tensile strength of ASTM A36 steels. The increase in ferrite grain size alone resulted in an increase in the ductility of ASTM A36 steels. Based on the results obtained in this study, multivariate linear regression equations are proposed to evaluate the post-fire yield strength of all three structural steels as a function of ferrite grain size and pearlite colony size. The results of this study will be useful to forensic engineers when evaluating the residual strength of fire-affected steel structures based on microstructures, especially when elevated temperature values are not available.
Get full access to this article
View all available purchase options and get full access to this article.
Data Availability Statement
All data, models, and code generated or used during the study appear in the published article.
Acknowledgments
The authors gratefully acknowledge the financial support from the North Dakota Established Program to Stimulate Competitive Research (ND EPSCoR).
References
Askeland, D. R., P. P. Fulay, and W. J. Wright. 2011. The science and engineering of materials. Stamford, CT: CL-Engineering.
ASTM. 2013. Standard test methods for determining average grain size. ASTM E112. West Conshohocken, PA: ASTM.
ASTM. 2014. Standard specification for carbon structural steel. ASTM A36/A36M. West Conshohocken, PA: ASTM.
ASTM. 2015. Standard specification for structural steel shapes. ASTM A992/A992M-11. West Conshohocken, PA: ASTM.
ASTM. 2018. Standard specification for high-strength low-alloy columbium-vanadium structural steel. ASTM A572/A572M. West Conshohocken, PA: ASTM.
Aziz, E. M., and V. K. Kodur. 2016. “Effect of temperature and cooling regime on mechanical properties of high-strength low-alloy steel.” Fire Mater. 40 (7): 926–939. https://doi.org/10.1002/fam.2352.
Bhadeshia, H. K. D. H. 2020. “Cementite.” Int. Mater. Rev. 65 (1): 1–27.
Callister, W. D., and D. G. Rethwisch. 2010. Materials science and engineering: An introduction. New York: Wiley.
Campbell, P., E. Hawbolt, and J. Brimacombe. 1991. “Microstructural engineering applied to the controlled cooling of steel wire rod. Part II: Microstructural evolution and mechanical properties correlations.” Metall. Trans. A 22 (11): 2779–2790. https://doi.org/10.1007/BF02851372.
Chawla, K. K., and M. Meyers. 1999. Mechanical behavior of materials. Englewood Cliffs, NJ: Prentice Hall.
Chi, J.-H., and P.-C. Peng. 2017. “Using the microstructure and mechanical behavior of steel materials to develop a new fire investigation technology.” Fire Mater. 41 (7): 864–870. https://doi.org/10.1002/fam.2438.
Choquet, P., P. Fabregue, J. Giusti, B. Chamont, J. N. Pezant, and F. Blanchet. 1990. “Modeling of forces, structures and final properties during the hot rolling process on the hot strip mill.” In Proc., Int. Symp. on Mathematical Modeling of Hot-Rolling of Steel, 34–43. Montreal: Canadian Institute of Mining and Metallurgy.
Clemens, H., S. Mayer, and C. Scheu. 2017. “Microstructure and properties of engineering materials.” In Neutrons and synchrotron radiation in engineering materials science: From fundamentals to applications, 1–20. Weinheim, Germany: Wiley-VCH.
Cuddy, L., and J. Raley. 1983. “Austenite grain coarsening in microalloyed steels.” Metall. Trans. A 14 (10): 1989–1995. https://doi.org/10.1007/BF02662366.
Davis, J. R. 2001. Alloying: Understanding the basics. Materials Park, OH: ASM International.
Garlock, M., I. Paya-Zaforteza, V. Kodur, and L. Gu. 2012. “Fire hazard in bridges: Review, assessment and repair strategies.” Eng. Struct. 35 (Feb): 89–98. https://doi.org/10.1016/j.engstruct.2011.11.002.
Gunalan, S., and M. Mahendran. 2014. “Experimental investigation of post-fire mechanical properties of cold-formed steels.” Thin Walled Struct. 84 (Nov): 241–254. https://doi.org/10.1016/j.tws.2014.06.010.
Hodgson, P. D., and R. K. Gibbs. 1992. “A mathematical model to predict the mechanical properties of hot rolled C-Mn and microalloyed steels.” ISIJ Int. 32 (12): 1329–1338. https://doi.org/10.2355/isijinternational.32.1329.
Kanvinde, A., and G. Deierlein. 2006. “The void growth model and the stress modified critical strain model to predict ductile fracture in structural steels.” J. Struct. Eng. 132 (12): 1907–1918. https://doi.org/10.1061/(ASCE)0733-9445(2006)132:12(1907).
Kiran, R., and K. Khandelwal. 2014. “A triaxiality and lode parameter dependent ductile fracture criterion.” Eng. Fract. Mech. 128 (Sep): 121–138. https://doi.org/10.1016/j.engfracmech.2014.07.010.
Kiran, R., and K. Khandelwal. 2015. “A coupled microvoid elongation and dilation based ductile fracture model for structural steels.” Eng. Fract. Mech. 145 (Aug): 15–42. https://doi.org/10.1016/j.engfracmech.2015.06.071.
Krauss, G. 2015. Steels: Processing, structure, and performance. Materials Park, OH: ASM International.
Lee, J., M. D. Engelhardt, and E. M. Taleff. 2012. “Mechanical properties of ASTM A992 steel after fire.” Eng. J. (Chicago) 49 (1): 33–44.
Li, G.-Q., H. Lyu, and C. Zhang. 2017. “Post-fire mechanical properties of high strength Q690 structural steel.” J. Constr. Steel Res. 132 (May): 108–116. https://doi.org/10.1016/j.jcsr.2016.12.027.
Lu, J., H. Liu, Z. Chen, and X. Liao. 2016. “Experimental investigation into the post-fire mechanical properties of hot-rolled and cold-formed steels.” J. Constr. Steel Res. 121 (Jun): 291–310. https://doi.org/10.1016/j.jcsr.2016.03.005.
Maraveas, C., Z. Fasoulakis, and K. D. Tsavdaridis. 2017a. “Post-fire assessment and reinstatement of steel structures.” J. Struct. Fire Eng. 8 (2): 181–201. https://doi.org/10.1108/JSFE-03-2017-0028.
Maraveas, C., Z. C. Fasoulakis, and K. D. Tsavdaridis. 2017b. “Mechanical properties of high and very high steel at elevated temperatures and after cooling down.” Fire Sci. Rev. 6 (1): 3. https://doi.org/10.1186/s40038-017-0017-6.
Naik, D. L., and R. Kiran. 2018. “Naïve Bayes classifier, multivariate linear regression and experimental testing for classification and characterization of wheat straw based on mechanical properties.” Ind. Crops Prod. 112 (Feb): 434–448. https://doi.org/10.1016/j.indcrop.2017.12.034.
Naik, D. L., H. U. Sajid, and R. Kiran. 2019. “Texture-based metallurgical phase identification in structural steels: A supervised machine learning approach.” Metals 9 (5): 546. https://doi.org/10.3390/met9050546.
N’souglo, K. E., A. Srivastava, S. Osovski, and J. A. Rodríguez-Martínez. 2018. “Random distributions of initial porosity trigger regular necking patterns at high strain rates.” Proc. R. Soc. A: Math. Phys. Eng. Sci. 474 (2211): 20170575. https://doi.org/10.1098/rspa.2017.0575.
Outinen, J., and P. Mäkeläinen. 2004. “Mechanical properties of structural steel at elevated temperatures and after cooling down.” Fire Mater. 28 (24): 237–251. https://doi.org/10.1002/fam.849.
Pała, R., S. Lipiec, and I. Dzioba. 2018. “Influence of the steel rolling direction on the mechanical properties and distribution of the local stress in front crack.” In Proc., IOP Conf. Series: Materials Science and Engineering, 012064. Bristol, UK: IOP Publishing.
Pickering, F. B. 1971. “Towards improved ductility and toughness.” In Proc., Climax Molybdenum Company Symp., 9. Tokyo: Iron and Steel Institute.
Pickering, F. B. 1978. Physical metallurgy and the design of steels. London: Applied Science.
Qiang, X., F. S. Bijlaard, and H. Kolstein. 2012. “Post-fire mechanical properties of high strength structural steels S460 and S690.” Eng. Struct. 35 (Feb): 1–10. https://doi.org/10.1016/j.engstruct.2011.11.005.
Rashid, M. S. 1980. “High-strength, low-alloy steels.” Science 208 (4446): 862. https://doi.org/10.1126/science.208.4446.862.
Roberts, B. W., and C. P. Thornton. 2014. Archaeometallurgy in global perspective: Methods and syntheses. New York: Springer.
Sajid, H. U., and R. Kiran. 2018a. “Influence of high stress triaxiality on mechanical strength of ASTM A36, ASTM A572 and ASTM A992 steels.” Constr. Build. Mater. 176 (Jul): 129–134. https://doi.org/10.1016/j.conbuildmat.2018.05.018.
Sajid, H. U., and R. Kiran. 2018b. “Influence of stress concentration and cooling methods on post-fire mechanical behavior of ASTM A36 steels.” Constr. Build. Mater. 186 (Oct): 920–945. https://doi.org/10.1016/j.conbuildmat.2018.08.006.
Sajid, H. U., and R. Kiran. 2019. “Post-fire mechanical behavior of ASTM A572 steels subjected to high stress triaxialities.” Eng. Struct. 191 (Jul): 323–342. https://doi.org/10.1016/j.engstruct.2019.04.055.
Samuels, L. E. 1999. Light microscopy of carbon steels. Materials Park, OH: ASM International.
Smith, C. I., B. R. Kirby, D. G. Lapwood, K. J. Cole, A. P. Cunningham, and R. R. Preston. 1981. “The reinstatement of fire damaged steel framed structures.” Fire Saf. J. 4 (1): 21–62. https://doi.org/10.1016/0379-7112(81)90004-7.
Srivastava, A., L. Ponson, S. Osovski, E. Bouchaud, V. Tvergaard, and A. Needleman. 2014. “Effect of inclusion density on ductile fracture toughness and roughness.” J. Mech. Phys. Solids 63 (Feb): 62–79. https://doi.org/10.1016/j.jmps.2013.10.003.
Tao, Z., X.-Q. Wang, M. K. Hassan, T.-Y. Song, and L.-A. Xie. 2019. “Behaviour of three types of stainless steel after exposure to elevated temperatures.” J. Constr. Steel Res. 152. 296–311. https://doi.org/10.1016/j.jcsr.2018.02.020.
Tao, Z., X.-Q. Wang, and B. Uy. 2013. “Stress-strain curves of structural and reinforcing steels after exposure to elevated temperatures.” J. Mater. Civ. Eng. 25 (9): 1306–1316. https://doi.org/10.1061/(ASCE)MT.1943-5533.0000676.
Tomota, Y., M. Umemoto, N. Komatsubara, A. Hiramatsu, N. Nakajima, A. Moriya, T. Watanabe, S. Nanba, G. Anan, and K. Kunishige. 1992. “Prediction of mechanical properties of multi-phase steels based on stress-strain curves.” ISIJ Int. 32 (3): 343–349. https://doi.org/10.2355/isijinternational.32.343.
Vander Voort, G. F. 2004. ASM handbook volume 9: Metallography and microstructures. Materials Park, OH: ASM International.
Wang, W., T. Liu, and J. Liu. 2015. “Experimental study on post-fire mechanical properties of high strength Q460 steel.” J. Constr. Steel Res. 114 (Nov): 100–109. https://doi.org/10.1016/j.jcsr.2015.07.019.
Wen, H., and H. Mahmoud. 2016. “New model for ductile fracture of metal alloys. I: Monotonic loading.” J. Eng. Mech. 142 (2): 04015088. https://doi.org/10.1061/(ASCE)EM.1943-7889.0001009.
Yu, Y., L. Lan, F. Ding, and L. Wang. 2019. “Mechanical properties of hot-rolled and cold-formed steels after exposure to elevated temperature: A review.” Constr. Build. Mater. 213 (Jul): 360–376. https://doi.org/10.1016/j.conbuildmat.2019.04.062.
Zhu, Y., M. D. Engelhardt, and R. Kiran. 2018. “Combined effects of triaxiality, lode parameter and shear stress on void growth and coalescence.” Eng. Fract. Mech. 199 (Aug): 410–437. https://doi.org/10.1016/j.engfracmech.2018.06.008.
Information & Authors
Information
Published In
Journal of Materials in Civil Engineering
Volume 32 • Issue 6 • June 2020
Copyright
©2020 American Society of Civil Engineers.
History
Received: May 30, 2019
Accepted: Nov 6, 2019
Published online: Mar 26, 2020
Published in print: Jun 1, 2020
Discussion open until: Aug 26, 2020
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.