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Vacuum carburizing or LPC, neutral hardening, oil or HPGQ (high pressure gas quench), vacuum pumps, graphite insulation, radiation shields or ceramic insulation, graphite or...
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...
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,...
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,...
The metallurgical R&D laboratory
Remembering old-school lab work is a blast from the past
Transformation of bainite from austenite
In this column, I will discuss the transformation of bainite from austenite.
Introduction
During the late 1920s, during studies of isothermal transformation of austenite —...
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)....
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....
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...
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...
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...
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...
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,...
Cleaning for heat treatment — Part III
Third 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...
Cleaning for heat treatment – Part V
Fifth 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...
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...
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...
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...
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...
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...
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...
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...
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...
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...
Carbon: Essential element or too much of a good thing
52100: Simple, yet it embraces carbon’s two-way benefit to steel
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...
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...
Tempered martensite embrittlement
In this column, I will discuss tempered martensite embrittlement and its primary causes.
Introduction
Once a part has been quenched, it must be tempered. This accomplishes...
Transformation of austenite to pearlite
In this column, I will discuss the different types of precipitation hardening stainless steels and discuss their physical metallurgy.
Pearlite was named by Henry Howe...
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-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: 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...
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....
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,...
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...
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...
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...
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 nickel-based superalloys
Heat treatment of nickel‑based superalloys is designed to control precipitation, dissolution, and coarsening of strengthening phases, primarily the ordered γ' phase in an FCC...
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...
