Future of heat treating of gears is similar to garage sale mentality
When and how does a heat treater determine whether to purchase new equipment or rebuild an old furnace?
Several years ago I participated in a...
Influence of agitation on polymer quenchants
Polymer quenchants are used extensively to quench a large variety of materials in a variety of processes. Polymer quenchants can be used for immersion...
Quench Factor analysis used to predict properties of quenched and aged aluminum
In this column, we will start to discuss the application of Quench Factor Analysis (QFA) to predicting properties of quenched and aged aluminum.
Quench Factor...
Cooling rate after tempering
In this column, I will discuss the effect of cooling rate after tempering.
Introduction
During heat treatment of steel, the process is generally austenitize, quench, and...
Thermal expansion of mineral oil quenchants
In this column, I will discuss the thermal expansion of oil. This information is primarily important for initial fills of a quench tank.
Introduction
Oil, when...
Use of molten salt in heat treatment
At the turn of the 20th century, the use of molten salt as a heating and quenching medium for steels was developed in England....
Intensive Quenching
Heat treating is similar to art in many ways, but not for the reasons you might think. Art, it’s said, is in the eye...
Classifying non-metallic inclusions in steels
In this column, we will discuss the different types of inclusions present in steels and discuss their physical metallurgy. As property requirements increase, and...
Furnace Maintenance
When a heat treat manager or anyone responsible for purchasing heat treating equipment makes a buy decision, they must first consider the process required,...
The big gamble: Electric vehicles or bust
There’s a big gamble going on in Detroit, and I don’t mean at Greektown Casino; it’s at the big three automakers. All have, in...
Blistering of aluminum during heat treatment
In this column, we will discuss the blistering of aluminum during heat treatment, and methods to prevent its occurrence.
Introduction
High-temperature oxidation, or blistering, often occurs...
Quench factor analysis: quench factor determination
In this column, we will discuss the determination of the quench factor as it is used in quench factor analysis. This will lead into...
Furnace Types
Heat treating furnaces consist of several subassemblies: insulation (fiber and brick), heating systems (electric and gas), material handling, quenching, atmosphere system, process and control...
The effect of temperature on cooling curve behavior
In this column, we will discuss the effect of temperature on the cooling curve behavior of quench oils.
Development of Quench Oil Maximum Operating Temperature
The...
The metallurgical R&D laboratory
Remembering old-school lab work is a blast from the past
Heat Treating, Furnaces, and Unintended Consequences
A few decades ago, my involvement with depleted uranium (DU) began in the metallurgical R&D department, developing program logic to heat treat DU in...
Safety considerations when quenching with oil or salt
In this column, we will consider safety aspects of quenching with oil or molten salt.
Heat treating is a manufacturing process where the goal is...
Understanding the effect of boron in steels
In this column, we will discuss the effect of boron additions to steel and its influence on properties.
Boron, B, is an element with an...
Quench factor analysis: C-curve determination
Previously, I discussed the concept of the quench factor, as developed by Staley . We showed that it was possible to determine properties as...
Understanding the Jominy end quench test
The Jominy end quench test (ASTM A255 ) is an extremely simple and useful test that is applicable to many materials besides steel...
Intergranular corrosion of austenitic stainless steels
In this column, I will discuss the intergranular corrosion of austenitic stainless steels (3XX) and discuss the thermal processing causes.
Introduction
Austenitic stainless steels, such as...
Heating with natural gas
It’s no secret that the heat treating industry is one of the major recipients of the impact when the U.S. Environmental Protection Agency (EPA)...
Some things old can be new again
Why heat-treating furnaces look the way they do
Heat treatment of aluminum – Part I: Quenching basics
In previous articles, we discussed the role of alloying elements and discussed the solution heat treatment of aluminum. We showed that it is important...
Effect of temperature on oxidation of oil quenchants
In this column, I will discuss the effect of temperature on the oxidation behavior of martempering oil used for distortion control.
Introduction
Martempering oils are used...
Hardenability – the influence of tramp elements
Hardenability is the property of a material to deeply harden, and not the ability to get hard . This basic concept has driven much...
Revisiting the 1:1 Rule for oil quenchants
The rule of thumb “one gallon of oil to one pound of parts and fixtures” has been in the literature for a long time....
Estimating required flow through quench tanks
In this month’s column, I will discuss a method of estimating the required flow for a quench tank.
Agitation has a significant effect on...
Thermal separation of polyalkylene glycol quenchants
Polyalkylene glycol quenchants are used in a variety of different heat-treating applications. One very common application is quenching of large steel and aluminum components....
Let’s hear it for welding
Heat-treating and metallurgy are topics that attract the overwhelming interest of attendees of technical conferences and are written about in numerous articles. However, a...
Quench tank agitation by submerged jets
In this column, I will discuss agitation by submerged jets.
Common methods of agitating quench tanks, and other types of tanks, are by sparging or...
Stainless Steels
Kitchen sinks, refrigerator or oven doors, and tableware are what many people think of when they are asked what’s made from stainless steel (SS)....
Hardening power: A measure of quenching performance
In this column, we will discuss the Segerberg Hardening Power (HP) for polymer quenchants.
When comparing polymer quenchants, there are several things that we look...
Troubleshooting induction hardening problems – Part III
In previous columns, I have provided some detail on the sources of problems with induction hardening. While I have tried to be inclusive, there...
Find the right equipment
Vacuum carburizing or LPC, neutral hardening, oil or HPGQ (high pressure gas quench), vacuum pumps, graphite insulation, radiation shields or ceramic insulation, graphite or...
