Stress corrosion cracking is an insidious form of damage that can occur when a susceptible metal is subjected to a tensile stress in a specific environment. To relieve tensile stresses at welded joints, postweld heat treatment can be helpful in reducing the susceptibility of carbon steel fabrications to SCC. When planning to use stainless steels in chloride-containing environments, it is advisable to select alloys that have been specifically developed to resist stress chloride cracking such as ferritic-austenitic (duplex) alloys, low-carbon ferritic alloys, and 6% Mo austenitic alloys or to select high-nickel alloys.

Nitinol fatigue fracture surfaces generally exhibit similar features to most engineering alloys, including a flat fracture plane, ratchet marks, radial lines, beachmarks, and striations.

A look at how bifilms are created during casting may offer clues to eliminating cracks, tensile fracture, fatigue failure, pitting, and stress corrosion cracking failures.

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.

Modeling shows that achieving required gear performance in a reduced gear size is possible by changing the steel grade and heat treatment parameters during the design stage. This article describes work in which virtual computer models using DANTE software are applied to help achieve gear size reduction by including steel grade hardenability and heat treatment parameters in the design process.

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

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.

Computer modeling is used in the design and development stages of induction hardening to optimize the process and to improve component quality including hardness, beneficial stress distributions, and reduced distortion.

By effectively mitigating the historical paradox between strength and ductility, a new advanced high strength steel with a mixed microconstituent structure enables automotive sheet steel to meet automobile efficiency requirements.

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.

Novel bcc CoCr-base alloys exhibit a Young’s modulus similar to human bone combined with superelastic strain twice that of NiTi alloys.

This article describes a new document on methods to test the bond strength of thermal spray coatings that was developed and released by the ASM Thermal Spray Society Accepted Practices Committee on Metallography. This practice clarifies details of ASTM C633 requirements and provides examples of best practices confirmed by hundreds of tests performed wordwide

The Center for Heat Treating Excellence (CHTE) was founded with the goal of bringing the industrial sector and university researchers together to find solutions to real-world problems. The Center, located at Worcester Polytechnic Institute (WPI) in Massachusetts, has 19 members from all areas of industry working together with WPI researchers to improve both heat treat and thermal processing methods worldwide. This article describes some of the current CHTE research projects.

This case study describes how electron-beam melting, a powder bed additive manufacturing technology, helped reduce the cost and material scrap associated with the production of Ti-6Al-4V brackets used in the hot side of the engine on Lockheed Martin's Joint Strike Fighter.

A new high-strength steel developed for cold stamping addresses the challenges presented by materials traditionally used to manufacture electric vehicle components.

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

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.

Fasteners play a critical role in engineered structures as a method of nonpermanent joining for the aerospace, infrastructure, civil, automotive, energy generation/distribution, and many other industries. Fastener failures can lead to disastrous consequences and substantial financial losses. One of the most common fastener failure modes is fatigue crack initiation and growth. Inadequate design considerations, material problems, insufficient preload, loosening, and excessive loads can all contribute to fastener fatigue. A case study of steel screw failures highlights some of the critical manufacturing and design factors that affect fastener fatigue.

Successful use of composite materials requires a thorough understanding of their mechanical properties. Although a range of mechanical tests is required to obtain data, the aerospace industry has already developed, validated, and standardized these test methods. This article reviews some of key test methods used with composites.

Molybdenum aluminum boride (MAB) phases have layered nanolaminate structures, suiting them for potential use in cutting tools, leading edges for hypersonic vehicles, high-temperature electrodes, and other demanding applications. This case study demonstrates a process for the production of MoAlB particulates and their incorporation in polymer-matrix composites.