Martensitic Microstructural Systems in Carbon-Steels and Susceptibility to Hydrogen Embrittlement
George Krauss, Ph.D.
Colorado School of Mines
Quench and tempered microstructures in low-carbon and medium-carbon low-alloy steels are complex microstructural systems with many components, including dislocation fine structure, inclusions, eta/epsilon transition carbides, martensite crystal interfaces, martensite block and packet boundaries, cementite particle distributions, prior austenite grain boundaries, and alloy carbides and nitrides, depending on steel chemistry and tempering intensity. Each of these microstructural components may interact as trapping sites for hydrogen and may contribute to reduced ductility, reduced toughness, or brittle intergranular and transgranular fracture. This lecture will explore the interrelationships of hydrogen and martensitic microstructures tempered to various strength levels.
Dr. George Krauss is currently University Emeritus Professor at the Colorado School of Mines and a metallurgical consultant specializing in steel microstructural systems. He received the B. S. in Metallurgical Engineering from Lehigh University in 1955 and the M. S. and Sc. D. degrees in Metallurgy from the Massachusetts Institute of Technology in 1958 and 1961, respectively, after working at the Superior Tube Company as a Development Engineer in 1956. He served at Lehigh University as Assistant Professor, Associate Professor, and Professor of Metallurgy and Materials Science from 1963 to 1975, and in 1975, joined the faculty of the Colorado School of Mines as the AMAX Foundation Professor in Physical Metallurgy. He was the John Henry Moore Professor of Metallurgical and Materials Engineering at the time of his retirement from the Colorado School of Mines in 1997.
He has authored the book Steels: Processing, Structure, and Performance, ASM International, 2005, coauthored the book, Tool Steels, Fifth Edition, ASM International, 1998, and edited or co-edited conference volumes on tempering of steel, carburizing, zinc-based coatings on steel, and microalloyed forging steels. He has published over 300 papers and lectured widely in technical conferences, universities, corporations and ASM International Chapters, presenting a number of keynote, invited and honorary lectures.