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...
Carburizing Optimization & ECD Precise Control
As discussed in the September/October 2016 Metal Urgency column , carburizing is a nonsteady-state diffusion process and thus can be expressed by Fick’s second...
AMS2750F contains key pyrometric changes
By now, most heat treaters should have had some time to read the new revision of AMS2750. The changes are extensive and, since it...
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...
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...
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...
Hydrogen basics for industrial burners
Modern concerns for sustainable manufacturing are driving significant interest and investment in hydrogen as an industrial fuel. Because burning hydrogen produces no carbon emissions,...
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...
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...
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...
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...
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...
Gas Nitriding
In general, nitriding of parts involves a thermal process that provides a tough, corrosion-resistant, and wear-resistant surface with less distortion compared to other case...
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...
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...
Linear-elastic fracture toughness testing
Materials fracture occurs in all sectors of the economy — aerospace, nuclear, medical, transportation, oil and gas, petrochemical, commercial and residential buildings, etc. The...
Variation in steel hardenability
Many heat-treating processes cannot tolerate appreciable variations in steel hardenability. For an established in-control process, deviations in chemical composition and starting microstructure may result...
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)....
Process quality control in heat treatment
In thermal processing, process quality control is imperative to produce and control conforming product and overall conformance. In this article we will be examining...
Different Scales Are Used For Rockwell Hardness Testing
Production Bench Rockwell Hardness Testing of Small Work Pieces
As induction hardened workpieces get smaller in size, attention to the proper abrasive cutting of the...
Vacuum Furnace Leaks
The process of finding leaks in your vacuum heat-treating system can sometimes be a lengthy process. However, a deeper understanding of best practices for...
Compelling reasons normalizing produces high quality gears
In this day and age, adding steps to the gear manufacturing process is not highly desirable unless the benefits far outweigh the costs incurred....
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...
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...
Handling temperature variations
Four essential maintenance steps for preserving temperature uniformity in your atmosphere furnace
Keeping your burners tuned
The backbone of any atmosphere furnace is the heating system. The heating system plays an essential role in keeping the furnace operating at peak...
An overview of heat treatment techniques
Editor’s note » This is the second in a five-part series.
In this second segment of my series on heat-treating techniques, I will discuss the...
Heat treatment techniques overview
Editor’s note » This is the third in a five-part series.
In this third segment of my series on heat-treating techniques, I will discuss the pros and...
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...
Variation in Hardenability
Many heat-treating processes cannot tolerate appreciable variations in steel hardenability. For an established in-control process, deviations in chemical composition and starting microstructure may result...
Creep deformation mechanisms in 9CrMo steel
The Generation-IV reactors in nuclear power plants are expected to address the growing energy demand by producing electricity and, at the same time, mitigating...
The meta-stable microstructure of martensite
In this column, we will discuss martensite and its formation.
Heat treating steel involves heating the component into the austenite range. Once the part is...
Furnace Atmospheres
The makeup of a furnace’s atmosphere in the heat treating process varies depending upon the application. Sensor technology allows for the in-situ monitoring of...
Heat-treatment of modified 9CrMo steel
The modified 9CrMo steels, such as Grade 91, Grade 92, and HT9, are materials of choice for fossil-fuel-fired power plants and Next Generation Nuclear...
AMS2750E, Nadcap requirements
When I consult, I will periodically perform a gap analysis on a supplier’s heat-treat process to either obtain Nadcap approval or as a check-and-balance...
Achieving results through cold treatment
Cold treatment is a sub-zero thermal treatment process primarily used to reduce the retained austenite content of alloy and high carbon steels. Cold treatment...
Surface stress is key in rolling contact fatigue
Most bearing failures can be attributed to some form of rolling contact fatigue. Many factors influence rolling contact fatigue, but two main factors are...
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...
Tailoring advanced ceramics to meet niche properties
Ceramics are traditionally described as inorganic, nonmetallic solids that are prepared from powdered raw materials and fabricated into products through the application of heat....
A brief history of the non-ferrous alloy aluminum
Non-ferrous alloys have caught my interest throughout my career, particularly aluminum. From its resistance to corrosion to its sensitivity at elevated temperatures, it is...
