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...
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...
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...
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...
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...
Hardening and tempering in the same cell
Tempering hardened steels is one of the most important heat treating processes used in part manufacturing. Induction tempering produces hardness and mechanical properties similar...
Hardening depth measurement
Surface hardening heat treatments are popular in the manufacture of steel products as a means of significantly improving strength and fatigue resistance and mitigating...
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...
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...
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...
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...
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,...
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,...
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...
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...
Compelling reasons normalizing produces high quality gears
In this day and age, adding steps to the gear manufacturing process is not highly desirable unless the benefits far outweigh the costs incurred....
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...
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...
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...
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,...
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,...
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...
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...
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...
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...
Residual stress evaluation in bearings
Lingering stress is not easily identified during production, but has a direct impact on wear performance and fatigue life
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...
Variation in 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...
Determining Austenite Grain Size
Grain size is a critical metallurgical characteristic, significantly influencing design parameters such as strength and toughness. Austenite grain size (often referenced to as prior-austenite...
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...
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...
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...
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...
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...
Non-Martensitic Transformation Products (NMTP)
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,...
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...
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...
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...
