This study looks at whether adding an annealing step to the heat treating process has an effect on residual stress and distortion on hypoid gear sets. Test results indicate that the annealing heat treatment introduced between gear set soft cutting and case carburizing helped to minimize distortion.

This case study measures residual stress on a truck axle housing as it goes through the manufacturing process.

Residual stress exists in all classes of materials and significantly impacts many facets of product design and manufacturing. This article reviews residual stress formation, types of stresses, and measurement techniques. ASM International is launching a technical committee on residual stress to enable industry-wide collabration and to advance the science of this important phenomenon.

Tests conducted on vacuum carburized and quenched shafts identify variables that increase distortion and the magnitude of residual stresses.

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.

Deformation-induced martensite phase transformation during room temperature forming of austenitic stainless steel leads to higher residual stress. This article discusses the results of a study to determine the relationship between deformation-induced martensite phase transformation and residual stress in AISI Type 304 austenitic stainless steel (nominal 18% Cr, 8% Ni) after stamping.

This article series explores the indispensable role of characterization in the development of cold spray coatings and illustrates some of the common processes used during coating development.

As scientists and engineers continue to develop and investigate replacement tissues for patient disease, injury, and aging, proper mechanical characterization of biological materials is critical. This article provides an overview of some static mechanical testing, creep testing, stress-relaxation testing, and fatigue testing methods for biomaterials applications.

High-speed, high-fidelity techniques used to analyze texture and dislocation content enable greater understanding of the influence of texture on deformation of titanium alloys than previously possible. This article describes a study in which specimens were examined using graphical slip band analysis to understand the influence of microstructure, alloy content, and loading orientation on the surface deformation response of titanium.

Because residual stress has a significant impact on engine component service life, understanding its cause helps optimize fabrication processes to ensure quality. X-ray diffraction is often the only viable technique to measure residual stresses at certain failure-critical locations. This article gives some guidelines for XRD analysis to understand and control residual stresses in processing of engine components.

Existing strain measurement techniques do not offer enough information about how failures occur, so alternative methods are needed. One technique involves using digital image correlation (DIC) to measure full field strain over the entire material surface. DIC works by capturing a series of images throughout a test and analyzing them afterwards.

This article describes the investigation conducted by the National Transportation Safety Board following an explosion triggered by a natural gas pipeline rupture. In addition to determining the likely cause of the rupture, the NTSB issued safety recommendations calling for hydrostatic pressure testing of similar gas lines and making them more amenable to inline inspection methods.

In this brief case study, finite element analysis and linear elastic fracture mechanics are used to evaluate new weld designs for large marine engines.

Neutron-based imaging and measurement techniques are an ideal complement to x-ray methods for characterizing additively manufactured materials and components. This article presents examples showing how neutron radiography and residual strain measurements reveal the internal structure and stress distributions in highly engineered turbine blades produced by additive processes. It also discusses the development of neutron characterization tools at ORNL and a recent effort in which they were used to evaluate stress-relief treatments for large-scale metal AM structures.