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...
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,...
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...
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...
Case Depth Determination
Methodology to ensure design intent is satisfied
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...
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...
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...
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...
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...
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...
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....
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...
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...
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...
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...
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...
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...
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...
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...
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...
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 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...
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...
Carbon potential verification
Choose from several verification methods for best fit, then develop a plan to correct for out-of-spec test results
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...
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...
Some workpieces are too large and expensive to fit into conventional benchtop hardness testers
Portable Rockwell Hardness Testing of Large Induction Hardened Work Pieces
The previous article identified many factors related to benchtop Rockwell hardness testing practices. This article...
Carburizing
While some heat treatments are used to soften the material or improve its machinability, most are processed to obtain strengthened or hardened properties. 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...
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...
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....
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,...
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...
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...
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,...
Residual stress evaluation in bearings
Lingering stress is not easily identified during production, but has a direct impact on wear performance and fatigue life
Different Scales Are Used For Rockwell Hardness Testing
Production Bench Rockwell Hardness Testing of Small Work Pieces
As induction hardened workpieces get smaller in size, attention to the proper abrasive cutting of the...
