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...
Cleaning for heat treatment
First in a series » Among the many specifications applied to finished heat-treated goods, the cleanliness of those goods is increasingly important in appearance, performance, and...
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...
Heat treatment of aluminum VI – Artificial aging
In the previous column, we described the fundamentals of natural aging. In natural aging, the solid solution obtained after quenching starts to form precipitates...
Aqueous inorganic salt quenchants
In this column, I will discuss the inorganic salt quenchants and how they can be used effectively to quench lean hardenability steel parts.
Often, a...
Polymer quenchants and corrosion of aluminum
When slow quenching 2024 aluminum, this alloy is susceptible to intergranular corrosion. Two common quenchants, water and AMS 3025 PAG type quenchants, are compared.
Introduction
Heat...
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...
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...
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...
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...
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,...
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,...
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 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...
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...
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...
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...
Developing a superalloy with superior heat resistance
Demand for superior machinery that can operate effectively under extreme conditions is driving the development of newer alloys. One significant example is the preparation...
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...
Transformation of pearlite, ferrite to austenite in steels
In this article, I will discuss the transformation of pearlite and ferrite to austenite during the heating of steel into the austenite region. This...
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...
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)....
Anatomy of a Heat-Treating System
Ninety-eight 600-pound trays are in continuous process, 13 are in the pre-process queue, nine preheating, 14 in the boost carb, eight in the diffusion...
Heat treatment of aluminum Part VII – Hardness and conductivity
In the previous article, we discussed the artificial aging of aluminum. Once we have heat treated the parts, we need to verify the properties....
Temper embrittlement in steels
The use of small additions of molybdenum reduces the susceptibility of steels to TE. Temper embrittlement (TE) occurs in quenched and tempered steels that...
Troubleshooting induction hardening problems: Part 1
Induction hardening is a unique method used to harden steels. The process uses a power supply, RF generator, induction coil, and quenching mechanism (spray...
Carbon: Essential element or too much of a good thing
52100: Simple, yet it embraces carbon’s two-way benefit to steel
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...
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...
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...
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...
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,...
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...
Removing sludge from quench tanks
In this column, I will discuss the formation of sludge in a quench tank, its prevention, and removal.
Introduction
As a quench oil is used, it...
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...
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...
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...
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...
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...
Vapor pressure of mineral oils
In this column, I will discuss vapor pressure of mineral oils, and how to calculate the vapor pressure as a function of temperature.
Introduction
As the...
