Alloy developers worldwide have struggled to create creep-resistant alumina-forming, iron-based austenitic stainless steels for use as high-temperature structural alloys, but with limited success in balancing alloy cost, oxidation, and creep resistance. This article describes the research and development of a novel cast alumina-forming austenitic stainless steel. This work won the prestigious Engineering Materials Achievement Award presented at IMAT 2023 in Detroit.

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 reviews steps to improve the cost and efficiency of electrical heating methods for vacuum furnaces based on recent technology developments. Topics addressed include improvements in durability and efficiency of industrial power supplies and digital power supply diagnostics.

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

Temperature measurement, unvented cavities, loose powder, and direct contact of certain metals must be considered during process development for vacuum heat treatment of additively manufactured parts.

Proper specification, measurement, and control of annealing furnace atmospheres are critical to reduce sooting, oxidation, sticking, and distortion. This article describes how to effectively design and utilize a nitrogen-hydrogen annealing atmosphere.

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.

Professor Induction answers a wide variety of questions regarding induction heating and heat treating. This article addresses differences between auto-tempering and self-tempering.

As a regular contributor to the HTPro eNewsletter, Professor Induction answers a wide variety of questions regarding induction heating and heat treating. Included here are three recent challenges and solutions.

Induction heating is used to produce high quality, reliable aerospace components as well as unique combinations of engineering characteristics.

A novel hot zone design featuring new graphite boards reduces heat loss and improves overall hot zone power requirements.

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.

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.

Understanding detrimental alpha case formation during heat treatment of titanium parts is increasingly important as titanium use in aerospace and medical applications continues to grow.

Residual gas analysis shows that vacuum furnaces with graphite hot zones are more economical than all-metal designs and are capable of producing contamination-free surfaces.

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.

Successful part brazing relies on proper joint design, part cleanliness, and correct fixturing of part assemblies. Routine furnace maintenance allows repeatable, quality brazing results over time. This article describes aluminum brazing processes and process control considerations.

Early consideration of scale-up requirements can help circumvent downstream problems when implementing thermal processes for the production of new materials and product forms. Examples are given showing how success is achieved when scaling opportunities and challenges are identified early in the development process.