Residual stress evaluation in bearings
Lingering stress is not easily identified during production, but has a direct impact on wear performance and fatigue life
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...
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...
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...
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...
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...
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...
Carbon potential verification
Choose from several verification methods for best fit, then develop a plan to correct for out-of-spec test results
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...
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...
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...
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...
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...
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...
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....
Wired for Cooling
Thermocouples are one of the most practical and widely used tools for gathering time/temperature data in thermal processing environments. Ranging from laboratory-scale experiments to...
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...
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...
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...
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...
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,...
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...
Books on steel for metallurgists and heat treaters
There are many books, papers, and publications that metallurgists and heat treaters rely on to assist with heat treating, material selection, failure analysis, or...
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...
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...
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...
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...
Distortion during heating
Minimizing distortion involves more than just optimizing cooling
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...
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...
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...
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...
