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...
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...
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...
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...
Some things old can be new again
Why heat-treating furnaces look the way they do
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...
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...
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...
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)....
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...
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,...
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...
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...
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...
Understanding the basics of spray quenching
Spray quenching involves the removal of heat by the impingement of a liquid quenchant on a hot metal surface. Examples include:
Fog quenching.
Quenching...
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...
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,...
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...
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,...
Heat treatment of aluminum, part II: Water quenching
In the last article, we talked about the metallurgy behind quenching aluminum. Now we are going to discuss the available quenchants for aluminum.
Introduction
To achieve...
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...
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...
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 metallurgical R&D laboratory
Remembering old-school lab work is a blast from the past
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...
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...
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...
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...
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...
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...
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...
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,...
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)...
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...
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...
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...
Using water as a quenchant
In this short column, we will discuss quenching with water. As a quenching medium, plain water approaches the maximum cooling rate attainable in a...
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...
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...
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...
