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...
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...
Sampling of quench oil for proactive maintenance
In this column, I will discuss the sampling of quench oil for quarterly checks as required by many internal and external auditing agencies (CQI-9,...
Widmanstätten ferrite
In this column, I will discuss the formation of Widmanstätten ferrite from austenite in steel. This microstructure has a unique appearance and shares some...
Control of distortion in heat-treated aluminum
In this column, we will discuss controlling the distortion of aluminum heat-treated components.
The heat treatment of aluminum (solution heat treatment, quenching and aging) are...
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...
Intensive Quenching Calls For Very High Cooling Rates Part 2
Intensive quenching (IQ) is defined as cooling, usually using pure water, at a rate several times higher than the rate of conventional quenching. Fast,...
Use of molten salts for martempering of steel
In July’s column, I talked about molten salts and the different types. In this short column, we discuss the benefits of using molten salts...
Determining the agitation needed in a quench tank
In this column, I will review the basic requirements of agitation, and illustrate a method of determining the right amount of agitation.
Recently, a customer...
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...
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...
Compatibility of polymer quenchants with metals, seals
In this column, I will discuss the compatibility of polymer quenchants and materials used in the construction of quench tanks, heat exchangers, and pump...
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....
Quenching from molten salt into polymer quenchants
In this column, I will discuss quenching aluminum from molten salt into a polymer quenchant.
A molten salt bath is a common method of heating...
Heat treatment of aluminum, Part V
After quenching and any straightening, the supersaturated solid solution of aluminum wants to reach equilibrium. It does this through the process of precipitation hardening....
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...
Heat treatment of aluminum, quenching Part III
In the last article, we discussed quenching of aluminum, and the importance of rapid quenching to prevent the formation of precipitates at the grain...
Sintering metal powders
In this column, I will discuss the process of sintering metal powders, an important part of manufacturing powder metallurgy (PM) parts.
Introduction
Powder metallurgy is a...
The effect of catalysts on quench oil oxidation
In the last column, I discussed the effect of temperature on the oxidation of a quench oil. As was alluded to in my last...
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...
Heat-treating workhorse – integral quench furnace
In this column, we will discuss the workhorse of the steel heat-treating industry – the integral quench furnace.
The integral quench furnace, or sealed quench...
Finding data needed for modeling and simulation
Modeling and simulation have become an important part of the design and manufacturing toolbox. Modeling and simulation are used in forging, casting, machining, forming,...
Delta ferrite formation in fasteners
During the manufacture of fasteners, the formation of iron phosphide as delta ferrite can occur during heat treatment. This can have a deleterious effect...
Titanium and its alloys
In this column, I will discuss the different types of titanium alloys and review their physical metallurgy.
Introduction
Titanium alloys are widely used in aerospace, chemical,...
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...
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...
Thermal triplets: PM, sintering, and case hardening
From my experience, powder metals (PM), sintering, and case hardening are three processes that could be said to be joined at the hip. More...
Troubleshooting induction hardening problems: Part 2
Last month, I began a two-part article about troubleshooting induction hardening problems and discussed possible corrections. This month, I will discuss biological and odor...
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 agitation on oil quenchants
In this column, I will discuss the effect of agitation on the cooling curve of oil quenchants.
Oil has been used for many years as...
Heat Treatment of Titanium Alloys
Last month, I discussed the different types of titanium alloys. In this column, I will discuss the heat treatment of alpha and near alpha,...
The heat treatment of aluminum – Introduction
Aluminum’s many desirable properties, such as high strength-to-weight ratio, good corrosion resistance, ease of processing, and low cost, make it a very widely used...
The metallurgical R&D laboratory
Remembering old-school lab work is a blast from the past
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...
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...
How did we get where we are today?
Having worked in the heat-treating industry for 58 years, I agreed in January 2011 to write a monthly column about all things heat-treating for...
Heat treatment of aluminum IV: Handling distortion
After quenching, depending on the quenchant used, distortion of parts can occur. This is particularly true for water-quenched parts. Parts must be straightened. This...
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...
Predicting hardness by the Grossman H-Value
In the last article, we described a method of calculating the Grossman H-Value . In the article before last, we described a method of...
Superalloys maintain strength, resist heat
Superalloys are used in a wide variety of applications that require oxidation resistance, high temperature creep resistance, and strength at elevated temperature. They are...
