Compared with traditional fatigue testing, the ultrasonic method achieves much speedier results along with the ability to run extremely high test cycles in a reasonable time frame.

Process optimization and optimal component performance can be achieved when multiple variables are measured and studied as a whole. In the investigation described in this article, fatigue performance of AISI 8620 H steel was characterized as a function of carburization case depth, hardness, residual stress, and retained austenite to demonstrate that an optimized carburization process could be engineered to meet specific application requirements.

Researchers at the Center for Heat Treating Excellence (CHTE) at Worcester Polytechnic Institute (WPI) are working with CHTE members to develop post-processing parameters to enhance the mechanical properties of additively manufactured (AM) steels. This article reports preliminary results based on characterization of AISI 8620 and 20MnCr5 powder, selective laser melted parts, and wrought parts.

This article describes research leading to the development of a new grade of low temperature bainitic steels, named Kinetically Activated Bainite (KAB) steels. with exceptionally rapid transformation kinetics at temperatures below 200°C. This entry won the Jacquet-Lucas Award for Best in Show at the 2015 International Metallographic Contest.

In order to expand the choice of materials available for use in additive manufacturing, parameters that consider welding metallurgy, laser powder interaction, and post processing must be developed. This article describes the outcomes of process development for a steel and stainless steel alloy that are not standard materials for laser powder bed fusion equipment.

Throughout metal making history, nothing has exceeded the technical importance, scientific complexity, and human curiosity involved in the hardening of steel. After the bustling 1890s, with its exciting and productive discoveries around steel metallography, a period of quiet consolidation occurred in the early 20th century. This article describes the breakthroughs in steel metallurgy that occurred after this period by such pioneers as William Chandler Roberts-Austen, Adolf Martens, Henry Marion Howe, and Edgar C. Bain.

The widespread use of alloy steels beginning in the early 1900s created the need to acquire and share information about heat treating, which previously had been a guarded art. This article describes advances in alloy steel technology in the late 1800s and early 1900s.

Flash processing, a new heat treatment for steels based on the concept of rapid thermal cycling, has been shown to achieve new levels of strength and ductility. This article describes the process, its effects on microstructure, and the phase transformations involved. It also discusses current and potential future applications.

Active screen plasma nitriding and nitrocarburizing are relatively new processes in which a plasma discharge is applied to a metal screen surrounding the workload, generating highly reactive gas species that flow to the component surface. The active screen also radiates heat, resulting in a uniform temperature throughout the load. This article provides an overview of the two processes and presents examples of their use on stainless steel piston rings (nitriding) and 4142 and 1045 steels (nitrocarburizing).

Compared to traditional power plant materials, creep strength enhanced ferritic steels require new approaches to nondestructive examination and weld repair. The metallurgical complexity of these steels prompted EPRI to conduct research to define and/or improve the detection limits of ultrasonic testing techniques, explore novel electromagnetic techniques, evaluate the sensitivity and applicability of acoustic emission testing, and conduct studies on improved weld repair procedures.

This article describes how shielding gas composition, either argon or nitrogen, affects the hardness, tensile strength, and toughness of high-power, high-brightness laser welds made on various base materials, including A508 forging steel, 316L stainless steel, Inconel 690, and solution-annealed IN718.

This work describes the development of a model to simulate the compound layer growth kinetics for nitriding AISI 4140 steel based on a customized Lehrer diagram. The model can be used to calculate concentration profiles of nitrogen as a function of time and position during the nitriding process and to predict the thickness of the compound layer. Winner of the 2012 HTS-Bodycote Best Paper in Heat Treating Award endowed by Bodycote Thermal Process-North America.