Welcome to ThermTech Marquenching Services

At ThermTech, we specialize in Marquenching—a cutting-edge heat treatment process designed to reduce distortion and enhance the properties of alloy-grade steel components. Our Marquenching services are ideal for a wide range of steel grades, including but not limited to Marquench 4340, Marquench 4140, Marquench 4150, Marquench 5160, Marquench 52100, Marquench 1095, and Marquench 1070 steel.

Why Marquenching?

Marquenching is the answer to a common problem encountered with certain steel alloys: excessive distortion and cracking during heat treatment. This unique process involves quenching components in hot molten salt instead of traditional oil or polymer quenching. The result? Reduced distortion and cracking, while still achieving an equivalent microstructure—a win-win for precision and performance.

Our Marquenching Capabilities

Atmosphere Furnace-to-Salt: Our state-of-the-art batch atmosphere furnace can handle components up to 36 inches in width, 72 inches in length, 54 inches in height, with a maximum weight of 7000 lbs. Parts are heated (austenitized) at temperatures ranging from 1500-1700°F before automatic transfer to the molten salt quench, maintained between 375°F to 500°F, depending on your specific steel grade. Finally, the parts are tempered to meet your desired hardness range.

Applications of Marquenching

Our Marquenching process finds its place in various applications:

Thin-Walled Materials: Marquenching is the preferred choice for materials with thin walls, effectively preventing distortion during the heat treatment process.

High Carbon and High Alloy Forgings: It’s the go-to solution for forgings made from high carbon and high alloy steel grades that are prone to cracking in traditional liquid quenching processes.

Minimizing Distortion: For components with heavier sections requiring specific core properties, alternative methods like oil quench hardening or polymer quench hardening may be recommended to meet specifications with minimal distortion.

Custom Solutions: At ThermTech, we are committed to helping you develop a process that meets all your part requirements while minimizing distortion. Contact us for personalized assistance tailored to your unique needs.

Austempering: For components extremely prone to distortion or cracking, consider our austempering process, which can also produce superior ductility properties in parts of all geometries.

Choose ThermTech for Marquenching Excellence

When precision and performance are paramount, choose ThermTech for Marquenching services. With our expertise, cutting-edge equipment, and commitment to quality, we ensure your alloy-grade steel components meet and exceed your expectations. Minimize distortion, reduce cracking, and elevate your components to their full potential with ThermTech Marquenching.

Contact us today to discuss your specific needs and discover how Marquenching can benefit your projects.

The Benefits of Marquenching Steel

In the world of metallurgy, different heat treatment processes are applied to modify the properties of metals. One such process is marquenching, also known as interrupted quenching. Marquenching is a heat treatment procedure used predominantly for steels to enhance various mechanical properties. This webpage delves into the benefits of marquenching steel, providing a comprehensive understanding of its advantages.

What is Marquenching?

Marquenching is a process where steel is austenitized (heated to a temperature where the steel transforms to the austenite phase) and then quenched in a medium (usually a molten salt bath) at a temperature just above the martensite start (Ms) temperature. After some time, the steel is removed from the quenching medium and cooled in air to ambient temperature, resulting in the transformation to martensite.

Benefits of Marquenching Steel

Reduced Distortion: One of the most notable benefits of marquenching is the reduction in dimensional changes and distortion compared to conventional quenching methods. This is due to the fact that the transformation from austenite to martensite happens at a relatively uniform rate and at a higher temperature than in traditional oil or water quenching.

Improved Toughness: Marquenching can enhance the toughness of steel. This is achieved by minimizing the formation of undesirable phases and reducing internal stresses that can initiate cracks.

Better Hardness Distribution: The uniform cooling and transformation associated with marquenching provide a more consistent hardness distribution throughout the steel component.

Less Risk of Cracking: Because of the slower cooling rate and less severe temperature gradient, there is a reduced risk of quench cracking when compared to more aggressive quenching methods.

Enhanced Wear Resistance: Certain steel compositions, when marquenched, can achieve enhanced wear resistance due to the resultant microstructure.

Environmentally Friendly: The quenching mediums used in marquenching, especially molten salt baths, are often more environmentally friendly than traditional quenchants like oil, which can produce smoke and other pollutants.


Economical: Given that marquenching can produce components with reduced distortion, there’s often less need for post-heat treatment machining or correction, leading to cost savings.


Marquenching offers numerous advantages for steel components, especially when dimensional stability, toughness, and wear resistance are crucial. With its ability to produce parts that require minimal post-treatment work and its environmentally friendly nature, marquenching stands out as a preferred heat treatment method for many steel applications.

ThermTech—Experts in Austempering Stampings, Machined Parts, and Investment Castings

ThermTech, Inc. offers both small and large batch capabilities for austempering steel and iron investment castings. Between our neutral salt bath furnaces and our larger austempering furnaces, we have the capabilities to austemper a wide variety of stamping, machined components, and investment castings. We have run austempering on alloys from 1060 through 4340 to ductile iron machined parts.

Our dedicated team works with you to ensure we meet your specifications. Count on our decades of experience with hardening, tempering, surface heat treatments, vacuum treatments, and annealing. To learn more about our services, please contact us today.

Learn more about austempering and how ThermTech can serve you by watching these videos.

Request a free quote online or call us at 800-752-6917. You can also contact us online for all your austempering and heat treating needs.

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ThermTech’s quality policy is ZERO DEFECTS for all customer products and in all quality management system activities. Through our efforts to continually improve the quality of the work we offer, we’ve been recognized as being able to meet the rigorous quality standards required by several of our major customers. ThermTech is certified for ISO 9001 and AS9100 in both Metal Heat Treat and Metal Finishing.