Tuesday, March 28, 2023


November 2012

Austempering: An Old Process with New Potential for Gears

The Austemper heat treat process was first developed in the 1930’s. Its application was initially limited to low volume, relatively small steel components. This has quietly changed in recent decades via the development of furnace technology and the process knowledge to produce Austempered Ductile Iron (ADI), Austempered steel, and Carbo-AustemperedTM steel. Austempered materials provide unique opportunities for […]

Variety of Furnaces Can Be Used for Heat Treatment of Gears

Gear heat treatment can be done in a wide variety of different types of industrial furnaces, each with its own unique characteristics. This article focuses on the similarities and differences of each of these styles. Classification of Heat-Treating Furnaces Heat-treating furnaces can be grouped into two main categories: batch and continuous. The fundamental difference between […]
Daniel H. Herring

How to Avoid Heat Treatment Problems When Launching New Gear Programs

So you’ve just secured an exciting new gear-manufacturing project and it’s time to start production planning. Heat treatment, such as carburizing, hardening and tempering, or nitriding, is a critical operation required to manufacture gears. It makes them wear-resistant, develops excellent mechanical properties, and increases fatigue life.  Heat treatment is also the source of many potential […]

A Case for Acetylene Based Low Pressure Carburizing of Gears

Low pressure carburizing (LPC) is the technology of choice for the precise carburizing of high-performance gearing [1]. To achieve absolute process repeatability and the highest quality outcome, it should come as no surprise that one of our goals is to fix as many of the process parameters (e.g. hydrocarbon gas type, pressure, flow rate, etc.) […]

New Simulation Software Tool Successfully Used in Carburizing Gears

In 1999 when the Center for Heat Treat Excellence (CHTE) was formed, the idea was to develop collaborative research between the industrial sector and university leaders to address the short and long-term needs of the heat-treating industry. One significant creation of that collaboration was the development of software to simulate the carburization heat treat of […]

Contour Hardening Bevel, Hypoid, and Pinion Gears

Traditional gear heat treatment involves gas carburizing in batch or continuous furnaces for an extended time, and then oil quenching. The gears are typically low temperature furnace tempered for a minimum of one hour at temperature. After carburization the carbon contents of the case region are typically within the range of 0.7-1.0 percent C. Surface […]

Maintenance Procedures for Vacuum Furnaces

More gear manufacturers need to add vacuum furnace machines to the shop floor and include this procedure in the overall manufacturing process. As vacuum furnaces are added, many maintenance issues arise. This article covers many aspects to ensure the quality output of these machines. Safety As with any piece of equipment, proper maintenance at regular […]
VAC AERO International Inc.

Rapid Stress Relief and Tempering

Stress relief and tempering are important processes, but they are still conducted much as they have been for the past 50 years. However, advanced equipment designs are available from Pyromaitre that permit these processes to be conducted in a fraction of the time than was formerly required, producing substantial improvements in productivity, cost, and energy […]
Mario Grenier, G.E. Totten, Roger Gingras