Carburizing and Steel
In carburizing, gears must be heated to reach the appropriate temperature for the steel grade without causing excessive grain growth and distortion in a...
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...
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...
The metallurgical R&D laboratory
Remembering old-school lab work is a blast from the past
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...
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...
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...
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....
Lighter Weight and Increased Fatigue Strength with Adi
Have you ever hit a rock or other hard projectile while cutting your lawn? Have you noticed that the blade is dented, not broken...
Process control is vital to heat-treating
The definition of process control can only be defined by the experience of the per-son to whom the query is presented. Everyone involved in...
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....
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,...
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,...
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...
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...
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...
Allocating space for case hardening furnaces
When selecting neutral or case hardening furnaces that require pits and have vertically mounted radiant tubes, facility managers must make sure that the equipment...
The mechanism of creep and its stages
In this column, I will discuss the mechanism of creep and its three stages.
Applications of metals at elevated temperatures involve several problems. It is...
Meeting Automotive Efficiency Standards
For automobiles where competing hardening processes and materials are involved, automotive designers and heat treaters have choices when deciding how to meet efficiency standards.
There...
Calculating decarburization
In this column, I will be talking about decarburization of steel and how to calculate its depth.
Introduction
Decarburization of steel is the depletion of carbon...
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...
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,...
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...
Intergranular oxidation in carburizing steels
Intergranular oxidation (IGO) in carburizing steels is detrimental to carburized gear performance. It reduces fatigue performance and can contribute to surface spalling. This article...
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...
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...
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...
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...
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...
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...
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...
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...
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...
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...
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...
