Thursday, October 17, 2019

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...

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...

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...

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...

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...

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,...

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...

Carbon potential verification

Choose from several verification methods for best fit, then develop a plan to correct for out-of-spec test results

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...

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...

Case Depth Determination

Methodology to ensure design intent is satisfied

Residual stress evaluation in bearings

Lingering stress is not easily identified during production, but has a direct impact on wear performance and fatigue life

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...

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...

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...

Aluminum heat-treating has unique challenges

From a metallurgical and quality perspective, aluminum heat-treating presents unique challenges when compared to carbon-based steels. This article will examine the aspects of aluminum...

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...

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...
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