Gas turbine coating’s life cycle

Gas turbines on land, air, and at sea experience some extreme environments, such as high airflow, pressure, and temperature. Engines intake air from outside...

Heat treatment process modeling development for age-hardenable alloys 

Age-hardenable alloys, such as some aluminum alloys, maraging steel, and nickel-based alloys, get their strength not from quenching but from the precipitation that occurs...

Heat treatment techniques overview

Editor’s note » This is the fourth in a five-part series.  In this fourth installment of my series on heat-treating techniques, I will discuss the pros...

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...

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...

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...

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...

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,...

Stress modeling of the WAAM process

A thermal model was previously developed and executed to simulate the Wire Arc Additive Manufacturing (WAAM) process, using the Goldak Flux Distribution to model...

Linear-elastic fracture toughness testing

Materials fracture occurs in all sectors of the economy — aerospace, nuclear, medical, transportation, oil and gas, petrochemical, commercial and residential buildings, etc. The...

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...

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,...

Kanthal APMT for nuclear-energy application

The major earthquake and tsunami that occurred in Japan in 2011 did serious damage to boiling water reactors of the Fukushima-Daiichi nuclear power plant....

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...

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...

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...

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...

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...

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...

Important to consider carbide formation during simulation

Low pressure carburizing (LPC) processes are a popular choice in industry due to LPC’s reduced cycle time, lack of oxidation/decarburization at and near surface,...

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...

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...

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...

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 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...

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...

Process comparison to improve fatigue performance

Bending fatigue and contact fatigue performance can be improved by the presence of residual compressive surface stresses . Many processes can induce these compressive...

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...

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...

Simulation tools to effectively calculate process

One common goal for a wide range of industries has been to increase power density in shaft and gear components. The steel producing industry...

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...

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...

Achieving results through cold treatment

Cold treatment is a sub-zero thermal treatment process primarily used to reduce the retained austenite content of alloy and high carbon steels. Cold treatment...

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...

Combatting undesirable NMTP formations

Whether formed during a conventional quench and tempering process, carburizing, or induction hardening, non-martensitic transformation products (NMTP) are widely considered undesirable microstructural features. However,...

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...

How to keep decarburization in check

The performance of heat-treated steel components is largely dependent on the condition of their surface. Wear and fatigue resistance are examples of design criteria...

Heat-treatment of modified 9CrMo steel

The modified 9CrMo steels, such as Grade 91, Grade 92, and HT9, are materials of choice for fossil-fuel-fired power plants and Next Generation Nuclear...

Retained austenite significant for strength, toughness

The role of retained austenite (RA) and the magnitude of its influence on the performance of steel components are continually debated. Depending on 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...