Surface stress is key in rolling contact fatigue
Most bearing failures can be attributed to some form of rolling contact fatigue. Many factors influence rolling contact fatigue, but two main factors are...
An overview of heat treatment techniques
Editor’s note » This is the second in a five-part series.
In this second segment of my series on heat-treating techniques, I will discuss the...
Characterizing equipment using simple modeling tools
Often, the terms “digital twins” or ICME (Integrated Computer Materials Engineering) are used when talking about computer modeling of actual parts or the behavior...
Using welding simulation tools to model WAAM
In its simplest form, additive manufacturing has been used since before the common era where low temperature melting materials such as tin, silver, copper,...
Heat transfer: Convection’s reach
Many years ago, as a mechanical engineering undergraduate student, an analogy was offered to help explain the interplay between convection and conduction in heat...
Induction Hardening Choices for Gears
Of the various types of applied energy processing, induction hardening is the most common. Induction heating is a process that uses an alternating electrical...
Heat treatment techniques overview
Editor’s note » This is the third in a five-part series.
In this third segment of my series on heat-treating techniques, I will discuss the pros and...
Creep deformation mechanisms in 9CrMo steel
The Generation-IV reactors in nuclear power plants are expected to address the growing energy demand by producing electricity and, at the same time, mitigating...
Why is modeling the immersion process so important?
Liquid quenching of long steel components can introduce significant distortion if the component is not lowered into the liquid quench bath properly. Whether the...
Hardness scale conversion
The use of hardness testing as a quality control method to check the outcome of a thermal treatment process is a common application of...
Accounting for carbon rejection can head off trouble
The heat treatment of steel alloys is required in almost every industry to acquire the necessary properties for a material given a particular application....
Evaluating effect of heat treat on flank slope profile deviation of steel gears using...
The finish machining of a gear is undoubtedly one of the most important manufacturing steps. It sets the geometry, surface condition, and residual stress...
Predicting strains key to evaluating heat-treat response
Quench hardening of steel components requires the components to be heated to a temperature such that the solid-state crystal structure of the material changes...
Low pressure carburization simulation of steel alloys with strong carbide forming elements
Low pressure carburizing (LPC) is quickly gaining popularity across many industries due to LPC’s reduced cycle time, lack of oxidation/decarburization at and near surface,...
Coupling Alloy and Process Selection
Combining both alloying and processing into a single strategy to achieve a desired level of performance sounds like a simple concept, but can be...
Distortion during heating
Minimizing distortion involves more than just optimizing cooling
Microstructural effect of Alloy 718 on fatigue strength
Gas turbine engines are widely used in aviation, power generation, and oil and gas industries. They are used in land, air, and marine. The...
Stress evolution during quench hardening of steel
Quench hardening of steel components involves complex, nonintuitive phenomena, particularly as it relates to the dimensional changes and stresses induced. Figure 1 shows a...
Carbon Diffusion and Carburizing Parameter Selection
Although carburizing is a complicated process, it can be broken down into two main steps: carbon generation in the furnace and carbon diffusion into...
Variation in steel hardenability
Many heat-treating processes cannot tolerate appreciable variations in steel hardenability. For an established in-control process, deviations in chemical composition and starting microstructure may result...
Nonlinear distortion response during gas quenching
High-pressure gas quenching (HPGQ) is touted as a way to reduce distortion of difficult-to-quench geometries. Quench pressures and quench gas flow velocities are chosen...
Materials Selection for Induction Hardening Processes
Induction hardening is the most common technique of the various types of applied energy processing. It uses alternating current that induces a magnetic field...
Carbon potential verification
Choose from several verification methods for best fit, then develop a plan to correct for out-of-spec test results
Press quenching tooling design using simulation
Steel powertrain gears are commonly carburized and quench hardened to improve strength and wear characteristics. However, solid-state phase changes occurring within the steel during...
Gear inspection methods from heat-treat simulation
Gear design is a complex process, involving dozens of parameters, tolerances, and relationships to mating components. Generally, professional standards guide the gear designer to...
Learning from failure in bending stress
A couple of years ago, as I was finishing my graduate studies, I was lucky enough to participate in the Strong Bar competition put on...
Carburizing Optimization & ECD Precise Control
As discussed in the September/October 2016 Metal Urgency column , carburizing is a nonsteady-state diffusion process and thus can be expressed by Fick’s second...
Fatigue failures in nickel-based austenitic Superalloy 718
Superalloy 718 is widely used for aerospace, nuclear, power generation, metal processing, medical, material processing, and chemical and petrochemical industries due to its excellent...
Metal plasticity in manufacturing
Understanding the plastic behavior of steel plays a crucial role in manufacturing. From raw billet to parts in service, some form of plastic deformation...
Enhanced properties of metal matrix nanocomposites
Application of carbon nanotube (CNT) reinforced metal matrix nanocomposite (MMNC) has been increasing rapidly since the discovery of CNT in the 1990s. These novel...
Determining austenite grain size
Grain size is a critical metallurgical characteristic, significantly influencing design parameters such as strength and toughness. Austenite grain size (often referred to as prior-austenite...
Cold expansion an efficient strengthening solution
In flight, aerospace components are in a state of constant cyclic stress. The term “flying fatigue machines” is commonly used by those in the...
Modeling can improve press quenching process
A combination of carburization and quench hardening is often used to increase the strength and improve fatigue performance of steel parts. During quenching, stresses...
Improving temperature uniformity during tempering
The final step in any steel heat-treatment quenching process which produces a martensitic microstructure is tempering. Martensite is a metastable phase and is extremely...
Evaluating a material’s response during austenitization
Carbon content in steel has a direct correlation to the hardness and overall strength of a component after heat treatment. Carbon can take many...
Microstructural evolution, its effect on Ti6Al4V alloy
Titanium alloys are extensively used in aerospace, petrochemical, marine, and medical applications, thanks to their superior strength-to-weight ratio at elevated temperature, corrosion resistance, and...
The meta-stable microstructure of martensite
In this column, we will discuss martensite and its formation.
Heat treating steel involves heating the component into the austenite range. Once the part is...
Testing of Induction Hardened Work Pieces
Hardness testing is a simple and universally accepted practice for checking induction hardened parts and is performed in literally thousands of manufacturing facilities. There...
Inducing heat treatment for case hardening
Induction hardening has become an increasingly popular heat-treatment method for steel due to its extremely fast processing speeds. Compared to other case hardening methods,...
Case Depth Determination
Methodology to ensure design intent is satisfied
