Wednesday, October 27, 2021

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...

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...

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...

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....

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,...

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....

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....

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...

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....

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...

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...

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...

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...

Heat treatment of aluminum – Part II

In my article last month, I discussed the alloying elements used in aluminum alloys. In this article, I will be discussing the solution heat...

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...

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...

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...

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...

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...

Determining Grossman H-value from cooling curve data

In the last article, I described how the Jominy end quench test could be used to predict hardness for a series of different round...

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...

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...

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...

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...

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...

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...

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...

Carburizing today: The secrets to predicting success

Predicting the outcome for today’s various carburizing processes requires different procedures and processes. Carburizing today is performed by two primary processes, at or above atmospheric...

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...

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...

The metallurgical R&D laboratory

Remembering old-school lab work is a blast from the past

Heat treating is not for the faint of heart

Why heat-treating furnaces look the way they do, Part 2

Some things old can be new again

Why heat-treating furnaces look the way they do

Carbon: Essential element or too much of a good thing

52100: Simple, yet it embraces carbon’s two-way benefit to steel

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...

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...

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...

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...

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...

Furnace Doors

No matter the configuration, single or multi-chamber vacuum, batch integral quench, continuous, or even pits — an item that all furnaces have in common...
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