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...
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...
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...
Residual stress evaluation in bearings
Lingering stress is not easily identified during production, but has a direct impact on wear performance and fatigue life
Carbon potential verification
Choose from several verification methods for best fit, then develop a plan to correct for out-of-spec test results
Case Depth Determination
Methodology to ensure design intent is satisfied
Distortion during heating
Minimizing distortion involves more than just optimizing cooling
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...
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,...
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...
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...
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...
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...
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...
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...
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...
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...
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...
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....
