Viscosity and the viscosity index

In this column, we will discuss the viscosity and viscosity index. Viscosity and the viscosity index are terms that are applied not only to...

A guide to creating a cleaning and washer control plan

In this column, I will discuss the control plan for a generic washer used for cleaning heat-treated parts. Proper cleaning involves not only removing the...

Control plan for oil-based quenchants

In this column, I will propose a simple control plan for oil-based quenchants and corrective actions. Oil quenchants have been used extensively to harden steel...

Selecting a cleaner for prewashing prior to heat treatment

In this column, we will discuss the selection of a cleaner for prewashing prior to carburizing. The choice is critical to avoid forming a...

Control plans for polymer quenchants

Polymer quenchants, whether used for immersion quenching or spray applications such as induction hardening, are much more difficult to control than oil quenchants. As...

Quench system design – heating and cooling

In this month’s column, we will discuss the heating and cooling of a quench tank. All quenching fluids have an optimum operating temperature range requiring...

Different methods of aqueous polymer concentration control

In this article, I will discuss the two different methods for controlling the concentration of polymer quenchants. This is applicable to either induction spray...

Transformation of retained austenite

In this month’s column, I will discuss the transformation of retained austenite, and its stabilization. In the last column, I reviewed the dimensional changes that...

Dimensional changes during tempering

In this column, I will discuss the dimensional changes that occur during tempering, with a short discussion of the underlying physical metallurgical changes. Introduction After quenching,...

Precipitation hardening stainless steels

In this column, we will discuss precipitation hardening steels and their physical metallurgy. Precipitation hardened stainless steels are a class of stainless steels that can...

Calibration of refractometers for control of polymer quenchants

In the last column, we described the use of refractometers for controlling the concentration of many different types of fluids, including polymer quenchants and...

Application of optical refractometers for the control of concentration

Optical refractometers, analog and digital, are widely used in industrial practice to measure the concentration of coolants, polymer quenchants, and fire-resistant hydraulic fluids, and...

Determining carbon potential for neutral hardening or carburizing

To successfully heat-treat or carburize the many different alloys seen in the heat-treating shop, it is necessary to properly control the carbon potential of...

Nondestructive testing VI – Radiography

In this article, we will be discussing the use of radiography (X-rays) for the detection of flaws. In the previous articles on nondestructive testing...

Nondestructive testing Part V:  Eddy current testing

In the previous column, I discussed ultrasonic testing of materials. In this column, I will be discussing Eddy Current NDT methods. History Eddy current testing is...

Non-destructive testing Part IV: Ultrasonic testing

In my previous articles, I have discussed dye penetrant inspection and magnetic particle inspection. In this article, I will give a brief overview of...

The basics of magnetic particle inspection

Magnetic particle inspection is a technique that is commonly used for ferromagnetic alloys for detecting surface and subsurface discontinuities. This method is extensively used...

Benefits of liquid penetrant inspection

Dye penetrant inspection is one of the most widely used non-destructive inspection techniques used. It is useful for a wide variety of product applications...

Introduction to nondestructive testing

Nondestructive testing (NDT) is an interdisciplinary science that uses many different methods to evaluate the properties of metals, parts, or assemblies without causing damage...

Fracture mechanics and fatigue crack growth

In the last article, we talked about fracture mechanics, and the method of fracture toughness testing using fracture mechanics. In this article, we are...
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