Tuesday, April 22, 2025

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...

Back to basics – Fracture toughness testing

In previous articles, we have discussed the many different types of mechanical testing methods and requirements. While some of the test methods have application...

Back to basics – Toughness testing of material

In the last series of articles, we discussed hardness testing and tensile testing. In these applications, the loading is a static load over a...

Back to basics: Mechanical testing – the tensile test

In the previous article, we discussed hardness testing, and the various methods of hardness testing were illustrated. In this article we discuss the tensile...

Back to basics: Hardness testing, Part 2

In last month’s Hot Seat article, we began a discussion on the various methods of mechanical property testing. Overall, we are going to discuss...

Back to basics: Hardness testing, Part 1

In a series of Hot Seat articles, we are going to discuss the various methods of mechanical property testing. We will be covering hardness...

Four basic types of fracture mechanisms: Part II

In the previous article, we discussed the fracture surfaces that are apparent for ductile or overload type fractures, and the fractures that occur with...

Four basic types of fracture mechanisms

When a component fails, the fracture surface of the broken component can tell a great deal regarding the mechanism of failure. It can often...

Cost, cleanliness, carbon footprint affect quenchant

Vegetable oils are seeing increased interest as quenchants for steel because of low carbon footprint, a renewable resource, and the ability to reclaim/recycle into...