AMP_04_May_June_2021_Digital_Edition

FEATURE A D V A N C E D M A T E R I A L S & P R O C E S S E S | M A Y / J U N E 2 0 2 1 6 5 1 tures, such as this example, can be linked to mechanical performance. With respect to fatigue performance, refined microstructures can increase fatigue resistance through increased crack deflection in the short crack growth re- gime. Further, retained austenite stability to mechanical- ly induced transformation to martensite affects mechan- ical behavior. Retained austenite stability is correlated to its size and morphology. For example, retained austenite stability increases as its size decreases, which is affected by PAGS as indicated in these results. In essence, micro- structure design for the next generation of fatigue resistant carburized steels will be informed by the advanced and de- tailed characterization of these critical constituents. CONCLUSION This article presents a case for employing advanced characterization techniques to surface hardened steels to build a richer understanding of the underlying metallurgi- cal phenomena. There is continued potential for collabora- tion between industry, academia, and research labs to use advanced characterization to accelerate development of surface hardened steels. ~HTPro Acknowledgment The authors gratefully acknowledge the support of the sponsors of the Advanced Steel Processing and Prod- ucts Research Center at the Colorado School of Mines and NSF-CMMI award number 1728007. For more information: Jonah Klemm-Toole, assistant professor, Colorado School of Mines, 1500 Illinois Street, Golden CO 80401, metallurgy.mines.edu , jklemmto@ mines.edu . References 1. K.A. Alogab, D.K. Matlock, J.G. Speer, and H.J. Kleebe, The Influence of Niobium Microalloying on Austenite Grain Coarsening Behavior of Ti-modified SAE 8620 Steel, ISIJ International, 47 (2), p 307-316, 2007. 2. E.J. Seo, J.G. Speer, D.K. Matlock, and R.L. Cryderman, Effect of Mo in CombinationwithNb on Austenite Grain Size Control in Vacuum Carburizing Steels. Journal of Materials Engineering and Performance, 29 (6), p 3575-3584, 2020. 3. C.M. Enloe, et al., Compositional Evolution of Microalloy Carbonitrides in a Mo-bearing Microalloyed Steel, Scripta Materialia, 68 (1), p 55-58, 2013. 4. J. Klemm-Toole, et al., Influences of Vanadium and Silicon on Case Hardness and Residual Stress of Nitrided Medium Carbon Steels, Metallurgical and Materials Transactions A, 52 (2), p 462-482, 2021. 5. J. Klemm-Toole, A.J. Clarke, and K.O. Findley, Improving the Fatigue Performance of Vanadium and Silicon Alloyed Medium Carbon Steels after Nitriding Through Increased Core Fatigue Strength and Compressive Residual Stress, Materials Science and Engineering A, 810 (141008), 2021. 6. M. Agnani, O.L. DeNonno, K.O. Findley, and S.W. Thompson, Quantitative Analysis of Microstructural Refinement in Simulated Carburized Microstructures, Journal of Materials Engineering and Performance, p 1-9, 2020. Interested in advertising with the ASMHeat Treating Society? Contact Kelly “KJ” Johanns at kelly.johanns@asminternational.org. 12 13