Tests conducted on vacuum carburized and quenched shafts identify variables that increase distortion and the magnitude of residual stresses.

Emissivity is a term used to define the ability of a surface to emit and absorb radiation. At any given temperature, the emissivity of a body (or surface) equals its absorptivity. Development work on a vacuum carburizing process revealed the need to better understand the effect of workload surface emissivity and the proper use of dummy thermocouple test blocks. This article reports on the findings from this research effort.

This article compares heat treat processes and furnace types that are typically used to harden gears.

There is growing interest in steels microalloyed with titanium, niobium, and molybdenum for use in high-temperature carburizing applications. This article describes methods for control of grain coarsening and work to commercialize microalloyed coarsening-resistant steels.

The Center for Heat Treating Excellence (CHTE) was founded with the goal of bringing the industrial sector and university researchers together to find solutions to real-world problems. The Center, located at Worcester Polytechnic Institute (WPI) in Massachusetts, has 19 members from all areas of industry working together with WPI researchers to improve both heat treat and thermal processing methods worldwide. This article describes some of the current CHTE research projects.

Using advanced characterization techniques on surface hardened steels builds a richer understanding of the underlying metallurgical phenomena.

Stringent pressure control and gas species type both play an important role in minimizing the evaporation rate of not only copper, but other elements susceptible to evaporation in vacuum systems. The article describes a study investigating the effect of temperature, pressure, and carrier gas species on the amount of copper evaporation that occurs from copper foil test samples in low pressure carburizing.

Engineers at the Ford Motor Co. are using integrated computational materials engineering (ICME) tools, allowing them to accurately simulate the heat treatment of gears and predict phase transformation kinetics and distortion.

High strength, corrosion-resistant Ferrium C64 is the culmination of a rigorous design process that bypassed extensive physical experimentation—delivering a carburizable steel with unmatched capability.

Members of the Center for Heat Treating Excellence are finding creative ways to bring awareness to careers in heat treating in order to recruit and retain top-notch talent.

In this article, the authors demonstrate the use of simulation software to optimize low-pressure carburizing (LPC) processes for high-alloy steels with strong carbide-forming elements.

Integral quenching (IQ) is a widely adopted heat treatment technique known for its efficient and rapid quenching capabilities. Vertical vacuum IQ furnaces give heat treaters a larger working zone for efficient and rapid quenching. This article describes the elements of a vacuum IQ furnace line and describes its operational workflow and process control.

This article focuses on five common reasons for distortion and cracking during heat treatment and recommended remediations: (1) Nonuniform and uncontrollable heat transfer during heating and cooling; (2) Structural changes during phase transformation; (3) Residual stresses in the part that occur due to forming, welding, or machining before heat treatment; (4) Macro or micro steel structure; and (5) Fixturing and loading errors.

New methods evaluate steel hardenability in a standard gas quench test and heat transfer coefficient variation within a furnace gas quench chamber.

Heat treaters are discovering new opportunities in the rapidly expanding field of additive manufacturing. This article describes some of the opportunities and challenges for heat treaters in this technology area.

Martempering involves cooling steel from the austenitizing temperature and rapidly cooling into either specially formulated petroleum oil or a molten salt bath with a specific composition to a temperature slightly above the martensite start (Ms) transformation temperature of the steel. Martempering is performed to reduce distortion problems that may be encountered with conventional quenching methods. This article, adapted from the latest ASM Handbook on quenching and quenchants, describes suitable steels for martempering and variables that influence the process.

Boriding is performed by diffusing boron atoms into a metal surface and allowing the boron to react with elements present in the substrate to form metal-boride compounds. Upon diffusing enough boron into the surface, a metal-boride compound layer with high hardness precipitates and grows below the surface of the part. This article discusses boriding of ferrous alloys, including a new deep case boriding method that produces wear layer depths comparable to competitive processes such as carburizing, nitriding, thermal spray coatings, and hardfacing.

Laser surface modification (LSM) techniques provide new pathways to improving the performance of engineered structures and components, either by altering surface metallurgy or chemistry or by adding a functional surface layer.

Accurate and continuous dew point measurement is key to maintaining the atmosphere required to achieve high quality and consistency of sintered products in powder metallurgy processing.

News about ASM members, chapters, events, awards, conferences, affiliates, and other society activities. Topics include: ASM names 2015 award recipients; Park Metallurgical/Heatbath Corporation in Detroit is selected for a 2015 ASM Historical Landmark Award; ASM student board members for 2015-2016 announced; Stan Theobald, former ASM Managing Director, retires from ASM; author spotlight for George Krauss; volunteer profile for Steve Brubaker.