The final day of Furnaces North America (FNA) began for Heat TreatToday with the presentation of a plaque to Timothy Joseph Wright (T.J. Wright), who served as a Major General in the U.S. Army, as well as a critical player in the history of heat treating, specifically as a past president of Wirco.
Two of his sons, Matthew Wright, vice president of marketing at pyrometry software company C3 Data, and Nathan Wright, CEO of C3 Data, joined T.J. at their booth for the presentation, as did his nephew, Chad Wright, current president of Wirco.
Heat TreatToday wishes to thank T. J., for his life of service to the country and to others and to the whole Wright family for their kindness and partnerships with us.
The day ended with the Metal Treating Institute’s (MTI) final event where MTI Yes Management Training graduates were recognized, awards were given to individuals and companies who have uniquely served the industry and MTI, and the 2025 MTI officers and board of trustees were announced.
Look for upcoming articles highlighting MTI news from the event!
Main image (left to right): Matthew Wright, T.J. Wright, Nathan Wright, Chad Wright
Achieving the elimination of oxidation during thermal treatment has driven heat treaters for decades and resulted in a wide variety of approaches. The obvious method is to flow an inert gas such as nitrogen into the furnace in order to drive out both air and moisture. By itself, however, this technique is inadequate.
The zirconia carbon sensor has been used for nearly three decades to control the carbon potential in many carburizing applications. Today’s best of the web article examines the use of the zirconia carbon sensor in a variety of annealing and special treatment applications and considers how the sensor millivolt output is preferred because it relates directly (not empirically) to the free oxygen concentration in the surrounding environment.
An Excerpt:
“While it is desirable to avoid oxidation during thermal treatment, the achievement of adequate control using one of the ‘getter’ gases requires that the sensor millivolts achieved be established at some value higher than the vee formed by the iron reaction at temperatures below 1375ºF and the carbon reaction above that temperature. The vee will demonstrate the lower limit, but the practical level should be established by evaluation of product quality, getter cost and possible sooting. The appropriate level will be limited by such things as furnace leaks, atmosphere agitation, work porosity, time of treatment, etc.”
In this installment of the Controls Corner, we are addressing load configurations in a furnace. An industrial furnace is made up of multiple zones for the heating of the load. These zones are strategically placed to minimize heat losses and to give the best heat profile for the application (minimize hot and cold spots in the vessel). In this Technical Tuesday installment, guest columnist Stanley Rutkowski III, senior applications engineer at RoMan Manufacturing, Inc., highlights the differences between power controls based on voltage and current.
This informative piece was first released inHeat Treat Today’sSeptember 2024 People of Heat Treat print edition.
The utility company transmits power to the electrical grid in terms of “voltage” and “current.” Voltage is the pressure to push the current through the wires. The amount of voltage required is a function of the losses in the system (resistance, reactance, and impedance). Utility companies transmit this via the highest voltage available to minimize the current. By minimizing the current, the cross section of the conductors to transmit gets smaller and less costly to run over long distances. At an industrial facility, a step down transformer (distribution type) is used to change the high voltage from the utility company to plant voltage (and by the same ratio increase the current from low to high).
In the operations of a furnace, the term commonly used is power, which is a multiplication of two variables, voltage and current.
In the operations of a furnace, the term commonly used is power, which is a multiplication of two variables, voltage and current. The utility company transmits power in a three-phase configuration with 120 degrees difference between phases (typically labeled A-B, B-C, and C-A). Let’s take a brief look at four major load configurations.
Single-Phase Load
A single-phase load uses one of the three legs of the system in operation. This type of system is best used in three zone applications to try to balance the power of each zone to the utility. A single-phase load allows for the most control of a zone in a furnace as it is individually controlled, but potentially causes the most disturbances to the utility company.
Two-Phase Load (Scott-T)
A Scott-T system is a way to balance load a three-phase system but allow for two loads in operation. In a five zone furnace, you could configure a three-phase system for the middle three zones and a Scott-T system for the first and last zones (front and back). A Scott-T system has a single point of control for the two zones to have the least disturbances to the utility company.
Three-Phase Load
A three-phase load can be in different configurations, the most common being Delta and Wye. The differences between them are the vectors of the voltage and current. A Wye system has less voltage and more current while a Delta system has less current and higher voltage. Care needs to be taken to minimize potential circulating currents that can be created by the vectors of three-phase systems. The three-phase system is a single point of control for the loads and causes less disturbances to the utility company. Mixing of three-phase systems inside a furnace (Delta and Wye) can help further minimize disturbances to the utility company.
IGBT (Insulated-Gate Bipolar Transistor)
An IGBT (Insulated-Gate Bipolar Transistor) system is a hybrid system that uses a three-phase primary to create a single-phase load. This allows for the highest level of control while minimizing the disturbances to the utility company. This system also allows the usage of higher frequencies to shrink the footprint of the transformers, allowing the use of rectification to minimize inductance and minimize the high current runs to the load(s).
About the Author:
Stanley F. Rutkowski III Senior Applications Engineer RoMan Manufacturing, Inc.
Stanley F. Rutkowski III is the senior applications engineer at RoMan Manufacturing, Inc., working on electrical energy savings in resistance heating applications. Stanley has worked at the company for 33 years with experience in welding, glass and furnace industries from R&D, design, and application standpoints. For more than 15 years, his focus has been on energy savings applications in industrial heating applications.
A car radiator manufacturer has expanded its heat treatment capacity with an EV/CAB line adapted for the production of oversized battery coolers. The aluminum brazing furnace facilitates the ability to make quick modifications and switch from gas to electric heating in order to meet climate change challenges.
Piotr Skarbiński Vice President of Aluminum and CAB Products Segment SECO/WARWICK Source: LinkedIn
SECO/WARWICK designed the CAB line with temperature uniformity across the entire belt width in order to accommodate the size specifications of the battery coolers.
“This order is for an aluminum brazing furnace adapted to the production of oversized battery coolers,” said Piotr Skarbiński, vice president of the aluminum and CAB product segment at SECO/WARWICK. “The EV/CAB line with a belt width of 2100 mm (6.89 ft) is designed to produce oversized battery coolers. It consists of a preheating and main heating chamber, a radiation brazing furnace, an air jacket cooling chamber, a final cooling chamber and a control system.”
The press release is available in its original form here.
Furnaces North America(FNA) 2024 begins Monday, October 14, and runs through Wednesday, October 16. If you haven’t registered yet, you can still do so onsite, and one look at the technical sessions planned over the two days of training says all you need to know about the caliber of instruction at the event.
All of the sessions will be worth your time! Presenters are highly qualified to speak on the topics, which range from processes and equipment to technology to security:
Emerging Technologies
Furnace Maintenance & Equipment
Heat Treat Business & Digital Transformation
Energy & Gases
Operational Efficiencies
Quality, Compliance & Materials
Process Advancements
If you want to do a little prereading to prepare for the sessions, Heat TreatToday is pleased to direct your attention to technical session presenters who have contributed to our radio, print, and digital resources during this year:
On Tuesday at 8:50 a.m., Bryan Stern, product development manager at Gasbarre Thermal Processing Systems, will be speaking on “The Impact of Oil Quenching – A Look at the Carbon Footprint and Cost of Vacuum vs. Atmosphere Processing.” On June 20, 2024, Bryan was our guest on Heat TreatRadio, episode #110, “Isolated Heat, the Future of Vacuum Furnaces,” which you can listen to here.
Later that morning, at 9:40, Peter Sherwin, global business development manager of Heat Treatmentat Watlow, will focus on “Smart Heat Treatment: Industry 4.0 Innovations for Environmental & Energy Efficiency.” Peter co-authored “Thermal Loop Solutions: A Path to a Sustainable Future in Heat Treatment,” a two-part series published in both the magazine and on our website. You can read the first part here and the second part here.
During that same time slot, Brian Turner, sales application engineer at RoMan Manufacturing, is scheduled to speak on “Efficient Furnace Power Solutions”. Brian joined fellow RoMan employees who have contributed technical content to an ongoing series on controls. You can read that article, “Basic Definitions: Power Pathways in Vacuum Furnaces,” originally published July 16, 2024, here.
On Wednesday at 8 a.m., Sefi Grossman, founder and CEO of CombustionOS, is scheduled to present a session on “Maximizing Heat Treat Operational Efficiency: Digitize Your Data for Automation.” Sefi wrote a piece for our August Automotive print edition on “A New Era: Tracking Quality Digitally,” which was later republished at the website. You can read the digital version here.
At 8:50, Joe Coleman, cybersecurity officer at Bluestreak Compliance, will address “CMMC’s Impending Impact On The Metal Treating Industry.” Just last month, he joined Heat TreatRadio in an interview about “NIST and CMMC: What Heat Treaters Need To Know,” which you can listen to here.
Chad Beamer, senior applications engineer at Quintus Technologies, will speak on “Quintus Purus: Development of Clean HIP Processing” at 9:40 on Wednesday morning. Earlier this year, he collaborated with fellow Quintus employees on an article, “HIP Innovation Maximizes AM Medical Potential,” which you can read here.
Bryan Stern Product Development Manager Gasbarre Thermal Processing SystemsPeter Sherwin Global Business Development Manager Heat TreatmentBrian Turner Sales Applications Engineer RoMan Manufacturing, Inc. Source: RoManSefi Grossman Founder & CEO CombustionOS Source: AuthorJoe Coleman Cyber Security Officer Bluestreak ConsultingChad Beamer Senior Applications Engineer Quintus TechnologiesHeat Treat Today contributors leading technical sessions at FNA 2024
Stop by Heat TreatToday‘s booth (424/426) to let us know how the sessions went and if you did your homework beforehand!
Plibrico, a manufacturer and installer of superior aluminosilicate and high alumina monolithic refractories, has expanded its footprint with the grand opening and dedication of its new state-of-the-art production facility in Oak Hill, Ohio. The company’s refractories are used in a variety of heat treating applications, and the new plant will enhance technology and production capacity.
Brad Taylor President & CEO Plibrico
Plibrico celebrated the occasion with a two-day GO LIVE Showcase, which included in attendance Shane Wilkin, Ohio State Senator; Samuel Brady, president and CEO of Economic Development Partnership of Jackson County; and Paul McNeal, mayor of Oak Hill. In addition to the dedication ceremony and training sessions, attendees received a behind-the-scenes tour of the company’s new refractory production facility. The event also featured discussions on innovation, growth, and development in the refractory industry.
“This facility represents more than just bricks and mortar,” said Brad Taylor, president and CEO of Plibrico, in his welcome address. “It symbolizes our dedication to innovation, growth, and a higher standard of excellence that we bring to our industry every day.”
Main photo: Brad Taylor, President and CEO of Plibrico, ribbon cutting to celebrate opening of new refractory production facility in Oak Hill, Ohio/ Source: Plibrico
The press release is available in its original form here.
The four heat treat industry-specific economic indicators have been gathered by Heat Treat Today each month since June 2023. Last month, suppliers were split between anticipated growth and no change or contraction. This month, the four economic indicators are all reflecting anticipated contraction.
The numbers, which were compiled in the first week of October, show that responding parties expect the economy to experience contraction in all the four indices. In three of the four, the numbers change by more than 5 points from growth or no change to contraction. For anticipated health of the manufacturing economy, suppliers anticipate contraction, although in an improved range.
The results from this month’s survey (October) are as follows; numbers above 50 indicate growth, numbers below 50 indicate contraction, and the number 50 indicates no change:
Anticipated change in Number of Inquiries from September to October: 44.6
Anticipated change in Value of Bookings from September to October: 44.8
Anticipated change in Size of Backlog from September to October: 42.9
Anticipated change in Health of the Manufacturing Economy from September to October: 43.8
Data for October 2024
The four index numbers are reported monthly by Heat Treat Today and made available on the website.
Heat TreatToday’sEconomic Indicatorsmeasure and report on four heat treat industry indices. Each month, approximately 800 individuals who classify themselves as suppliers to the North American heat treat industry receive the survey. Above are the results. Data started being collected in June 2023. If you would like to participate in the monthly survey, please click here to subscribe.
The Heat Treat Doctor® has returned to offer sage advice to Heat Treat Today readers and to answer your questions about heat treating, brazing, sintering, and other types of thermal treatments as well as questions on metallurgy, equipment, and process-related issues.
The Heat Treat Doctor® ha vuelto para ofrecer sabios consejos a los lectores de Heat Treat Today y para responder a suspreguntas sobre el tratamiento térmico, brazing, sinterizado y otros tipos de procesamiento térmico, así como preguntassobre metalurgia, equipos y problemasrelacionados con los procesos.
This article was originally published inHeat Treat Today‘sSeptember 2024 People of Heat Treat print edition.
Quenching is a critical step in the heat treating process. And while there are often several choices available to the heat treater, a delicate balance exists between what is available to us and how we can optimize its performance characteristics to meet our client’s requirements/specifications. Material, part design (geometry), pre-and post-manufacturing requirements, loading, allowable dimensional change (i.e., distortion), and the process itself must be taken into careful consideration. Let’s learn more.
Quenchants — A Brief Overview
Today’s quenchants offer a broad and, in some instances, overlapping range of capabilities. But at a fundamental level, the role of a quenchant is to extract heat from the part surface to meet a specified critical cooling rate and achieve the desired microstructure in the component part necessary to achieve the required mechanical and physical properties. In hardening of steels, for example, one must miss the “nose” of the time-temperature transformation (TTT) curve if the desired end-result is a martensitic (or bainitic) microstructure. By contrast, the cooling rate for a normalizing process requires cooling in “still air” — a term that is often misunderstood and which we will cover in a future discussion.
Figure 1. Common types of quenchants and their effect on distortion (See Reference 1)
However, a quenchant (Figure 1) is more than just its cooling rate. Quenchants should be stable over their service life, especially with respect to degradation (e.g., oxidation), be safe, be easy to service and maintain, have a high vaporization point, ideally not interact with the part surface, be used within their optimum performance range, have long life, be easily removed by cleaning after quenching, and be cost effective.
As a very broad-based characterization, quenchants can be divided into the following general categories:
Mixed media quenchants (e.g., mist or fog quenching, fluidized beds)
Figure 2. Ishikawa (aka fishbone) diagram of quenching variables (See Reference 1)
Selection of the Optimal Quench Medium
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Various factors must be taken into consideration when selecting the best quench medium. The following are some of the important considerations when selecting the proper quench medium (Figure 2):
Material — chemistry, hardenability, form (e.g., bar, plate, forging, casting), type (e.g., wrought, powder metal), and cleanliness to name a few
Part geometry/design — shape, size, weight, complexity
Mill or preheat treatment condition — annealed, normalized, pre-hardened, stress-relieved
Stress state — the cumulative effect of both mill operations and customer manufacturing operations prior to heat treatment
Process parameters — temperature, time, preheating
Equipment selection — is it optimal or simply adequate for the job?
Quench medium(s) available — their limitations as well as their advantages
It is important to talk briefly here about two aspects of the quench medium selection process. First, note the difference between hardness and hardenability (which we will discuss in more detail in the future). Heat treaters tend to focus on hardness (since we can easily measure it in our shops), but hardenability is a critical consideration in quench medium selection. Hardenability is a material property independent of cooling rate and dependent on chemical composition and grain size. When evaluated by hardness testing, hardenability is defined as the capacity of the material under a given set of heat treatment conditions to harden “in-depth.” In other words, hardenability is concerned with the “depth of hardening,” or the hardness profile obtained, not the ability to achieve a particular hardness value. When evaluated by microstructural techniques, hardenability is defined (for steels) as the capacity of the steel to transform partially or completely from austenite to a defined percentage of martensite.
Table 1. Average and instantaneous values of the heat transfer coefficient (See Reference 3)
Second, one must be aware of both the average and instantaneous value of the heat transfer coefficient alpha of the quench medium. Although the maximum quenching “power” may be described by the instantaneous heat transfer coefficient, the average heat transfer coefficient (Table 1) provides a better relative comparison of the various quenching media since it represents the value of the heat transfer coefficient over the entire range of cooling (from the start to the end of quenching). It is important to remember that the ability to manage (not control) distortion is a delicate balancing act between uniform heat extraction and proper transformation.
A Common Example — Quench Oil Selection
Important factors to consider when selecting a quench oil, which hold true in a slightly modified form for most liquid quenchants, are: the type of quenchant (i.e., quench characteristics, cooling curve data — new and over time); quench speed (see Table 2); usage temperature; effective quench tank volume (i.e., the one gallon per pound of steel [8.4 L/kg] rule); and the client’s requirements.
Table 2. Classification of quench oils (See Reference 1)
Quench tank design factors also play an important role and involve the following:
Volume of oil in the quench tank
Number of agitators or pumps
Location of agitators
Type of agitators (fixed or variable speed)
Internal tank baffle arrangement (draft tubes, directional flow vanes, etc.)
Quench elevator design (i.e., flow restrictions)
Quenchant flow direction (up or down through the load)
Propeller size (diameter, clearance in draft tube)
Maximum (design) temperature rise of the oil after quenching
Finally, consideration must be given to factors such as: part mass; part geometry (e.g., thin and thick sections, sharp corners and holes, gear tooth profile/modulus, thread profile, etc.); part spacing in the load; effective flow velocity through the quench area (empty and with a load); stress state from prior (manufacturing) operations; post heat treat operations to be performed (if any); loading including the grids, baskets, and fixture (material and design); and the material (chemistry and hardenability).
Final Thoughts
Quenching, considered by many to be a complex and multi-faceted subject, is one heat treaters must constantly monitor and control. In future installments we will be discussing many of the individual aspects of quenching. What is important here is to recognize that done correctly, quenching (in whatever form) will optimize a given heat treatment and help produce the highest quality parts demanded by the industries we serve.
References
Daniel Herring, Atmosphere Heat Treatment, Volume II: Atmospheres | Quenching | Testing (BNP Media Group, 2015).
Božidar Liščić et al., Quenching Theory and Technology, Second Edition (CRC Press, Taylor Francis Group, 2010).
Daniel Herring, “A Review of Gas Quenching from the Perspective of the Heat Transfer Coefficient,” Industrial Heating, February 2006.
About the Author
Dan Herring “The Heat Treat Doctor” The HERRING GROUP, Inc.
Dan Herring has been in the industry for over 50 years and has gained vast experience in fields that include materials science, engineering, metallurgy, new product research, and many other areas. He is the author of six books and over 700 technical articles.
The Heat Treat Doctor® ha vuelto para ofrecer sabios consejos a los lectores de Heat Treat Today y para responder a suspreguntas sobre el tratamiento térmico, brazing, sinterizado y otros tipos de procesamiento térmico, así como preguntassobre metalurgia, equipos y problemas relacionados con los procesos.
The Heat Treat Doctor® has returned to offer sage advice to Heat Treat Today readers and to answer your questions about heat treating, brazing, sintering, and other types of thermal treatments as well as questions on metallurgy, equipment, and process-related issues.
This article was originally published inHeat Treat Today‘sSeptember 2024 People of Heat Treat print edition.
El temple es un paso fundamental en el proceso de tratamiento térmico. Y si bien el especialista en tratamiento térmico suele tener varias opciones disponibles, existe un delicado equilibrio entre lo que está disponible para nosotros y cómo podemos optimizar sus características de rendimiento para cumplir con los requisitos/especificaciones de nuestros clientes. Se deben tener en cuenta cuidadosamente el material, el diseño de la pieza (geometría), los requisitos previos y posteriores de manufactura, la carga, el cambio dimensional permitido (es decir, la distorsión) y el proceso como tal. Conozcamos más.
Medios de temple: una breve Descripción
Los medios de temple actuales ofrecen una amplia gama de capacidades que, en algunos casos, se traslapan. Sin embargo, en un nivel fundamental, la función de un medio de temple es extraer calor de la superficie de la pieza para cumplir con una velocidad crítica de enfriamiento especificada y con ello lograr la microestructura necesaria para lograr las propiedades mecánicas y físicas requeridas. En el temple de aceros, por ejemplo, se debe evitar pasar por la “nariz” de la curva de transformación-tiempo-temperatura (TTT) si el resultado final deseado es una microestructura martensítica (o bainítica). Por el contrario, la velocidad de enfriamiento para un proceso de normalización requiere enfriamiento “al aire”, un término que a menudo se malinterpreta y que abordaremos en una discusión futura.
Figura 1. Medios de Temple comunes y su efecto en la distorsión (1)
Sin embargo, un medio de temple (Figura 1) es más que solo su velocidad de enfriamiento. Los medios de temple deben ser estables durante su vida útil, especialmente con respecto a la degradación (por ejemplo, oxidación), ser seguros, ser fáciles de arreglar y mantener, tener un alto punto de vaporización, idealmente no interactuar con la superficie de la pieza, usarse dentro de su rango de rendimiento óptimo, tener una larga vida útil, eliminarse fácilmente mediante limpieza después del temple y ser rentables.
A manera de una caracterización muy amplia, los medios de temple se pueden dividir en las siguientes categorías generales:
Medios de temple líquidos (p. ej., a base de agua, aceites, polímeros, sales fundidas y metales fundidos)
Medios de temple gaseosos (p. ej., aire, nitrógeno, argón, hidrógeno, vapor, dióxido de carbono, dióxido de azufre, gases reductores, atmósferas protectoras sintéticas o generadas, gases a alta presión)
Medios de temple sólidos (p. ej., dados de prensa enfriados, placas y polvos)
Medios de medios mixtos (p. ej., temple por aspersión, lechos fluidizados)
Figura 2. Diagrama de Ishikawa (también conocido como de pescado) de las variables de temples (1)
Selección del medio de temple óptimo
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Se deben tener en cuenta varios factores al seleccionar el mejor medio de temple. A continuación, se enumeran algunos de los aspectos importantes a tener en cuenta al seleccionar el medio adecuado (Figura 2):
Material: composición química, templabilidad, forma (p. ej., barra, placa, forja, fundición), tipo (p. ej., forjado, sinterizado) y limpieza, por nombrar algunos
Geometría/diseño de la pieza: forma, tamaño, peso, complejidad
Estado de laminación o tratamiento térmico previo: recocido, normalizado, preendurecido, relevado de esfuerzos
Estado de tensión: el efecto acumulativo de las operaciones de laminación y las operaciones de fabricación del cliente antes del tratamiento térmico
Carga: canastillas (aleación, compuesto C/C, placas de grafito, etc.)
Parámetros del proceso: temperatura, tiempo, precalentamiento
Selección del equipo: ¿es óptimo o simplemente adecuado para el trabajo?
Medio(s) de temple disponibles: sus limitaciones y ventajas
Es importante hablar brevemente aquí sobre dos aspectos del proceso de selección del medio de temple. Primero, observar la diferencia entre dureza y templabilidad (que analizaremos con más detalle en el futuro). Los tratadores térmicos tienden a centrarse en la dureza (ya que podemos medirla fácilmente en nuestro taller), pero la templabilidad es una consideración crítica en la selección del medio de temple. La templabilidad es una propiedad del material independiente de la velocidad de enfriamiento y dependiente de la composición química y el tamaño del grano. Cuando se evalúa mediante pruebas de dureza, la templabilidad se define como la capacidad del material bajo un conjunto dado de condiciones de tratamiento térmico para endurecerse “en profundidad”. En otras palabras, la templabilidad se relaciona con la “profundidad de endurecimiento”, o el perfil de dureza obtenido, no con la capacidad de alcanzar un valor de dureza particular. Cuando se evalúa mediante técnicas microestructurales, la templabilidad se define (para aceros) como la capacidad del acero para transformarse parcial o completamente de austenita a un porcentaje definido de martensita.
Tabla 1. Valores medios e instantáneos del coeficiente de transferencia de calor (3)
En segundo lugar, se debe tener en cuenta tanto el valor medio como el instantáneo del coeficiente de transferencia de calor alfa (α) del medio de temple. Aunque la “potencia” máxima de temple se puede describir mediante el coeficiente de transferencia de calor instantáneo, el coeficiente de transferencia de calor promedio (Tabla 1) proporciona una mejor comparación relativa de los diversos medios de temple, ya que representa el valor del coeficiente de transferencia de calor en todo el rango de enfriamiento (desde el inicio hasta el final del temple). Es importante recordar que la capacidad de gestionar (no controlar) la distorsión es un delicado acto de equilibrio entre la extracción uniforme del calor y la transformación adecuada.
Tabla 2. Clasificación de los aceites de temple (1)
Un ejemplo común: selección de aceite de temple
Los factores importantes a tener en cuenta al seleccionar un aceite de temple, que son válidos en una forma ligeramente modificada para la mayoría de los medios líquidos, son: el tipo de medio (es decir, características del temple, datos de la curva de enfriamiento, nuevo y a lo largo del tiempo); velocidad de temple (consulte a Tabla 2); temperatura de uso; volumen efectivo del tanque de enfriamiento [es decir, la regla de un galón por libra de acero (8,4 L/kg)]; y los requisitos del cliente.
Los factores de diseño del tanque de temple también juegan un papel importante e involucran lo siguiente:
Volumen de aceite en el tanque de temple
Número de recirculadores o bombas
Ubicación de los recirculadores
Tipo de recirculadores (velocidad fija ovariable)
Disposición de los deflectores internos del tanque (tubos de aspiración, álabes de flujo direccional, etc.)
Diseño del elevador de temple (es decir, restricciones de flujo)
Dirección del flujo del temple (hacia arriba o hacia abajo a través de la carga)
Tamaño de la propela (diámetro, espacio libre en el tubo de aspiración)
Máximo incremento dela temperatura (diseño) delaceite después del temple
Altura del aceite sobre la carga
Intercambiador de calor: tipo, tamaño, tasa de extracción de calor (BTU instantáneos/minuto)
Tiempo de recuperación del aceite hasta el set point
Por último, se deben tener en cuenta factores como: la masa de la pieza; la geometría de la pieza (por ejemplo, secciones delgadas y gruesas, esquinas y barrenos afilados, perfil de los dientes del engrane, perfil de la rosca, etc.); espaciamiento de la pieza en la carga; velocidad de flujo efectiva a través del área de temple (vacía y con carga); estado de tensión de operaciones anteriores (de manufactura); operaciones de tratamiento térmico posteriores a realizar (si las hay); carga, incluidas las charolas, las canastillas y el herramental (material y diseño); y el material (composición química y templabilidad).
Reflexiones finales
El temple, considerado por muchos como un tema complejo y multifacético, es un asunto que los especialistas en tratamiento térmico deben supervisar y controlar constantemente. En futuras entregas, analizaremos muchos de los aspectos individuales del temple. Lo importante aquí es reconocer que, si se realiza correctamente, el temple (en cualquier forma) optimizará un tratamiento térmico determinado y ayudará a producir las piezas de la más alta calidad que exigen las industrias a las que prestamos nuestros servicios.
Referencias
Daniel Herring, Atmosphere Heat Treatment, Volume II: Atmospheres | Quenching | Testing (BNP Media Group, 2015).
Bozidar Liscic et al., Quenching Theory and Technology, Second Edition (CRC Press, Taylor Francis Group, 2010).
Daniel Herring, “A Review of Gas Quenching from the Perspective of the Heat Transfer Coefficient,” Industrial Heating, February 2006.
Sobre el autor
Dan Herring “The Heat Treat Doctor” The HERRING GROUP, Inc.
Dan Herring ha trabajado en la industria durante más de 50 años y ha adquirido una vasta experiencia en campos que incluyen ciencia de materiales, ingeniería, metalurgia, investigación de nuevos productos y muchas otras áreas. Dan es autor de seis libros y más de 700 artículos técnicos.
Para más información: Comuníquese con Dan en dherring@heat-treat-doctor.com.
For more information about Dan’s books: see his page at the Heat Treat Store.
Find Heat Treating Products And Services When You Search On Heat Treat Buyers Guide.Com
A manufacturer of components for the aviation and energy sectors is expanding its production capabilities with the acquisition of a horizontal vacuum heat treatment furnace. Huake Casting Control (Shanghai) Technology Co., Ltd., will use the equipment to manufacture precision gas turbine components and aircraft parts.
A Vector® horizontal vacuum heat treatment furnace Source: SECO/WARWICK Group
The solution, a member of the Vector® family of furnaces provided by SECO/WARWICK Group, comes with a graphite heating chamber and a 15-bar absolute gas quenching system, can operate at temperatures up to 2550°F (1400°C), and has a maximum gross load weight of 1767 lb (800 kg).
“We were convinced to choose the Vector furnace because of its wide range of heat treatment processes and applications, fast cycles with high pressure gas quenching and low consumption of energy, process gases and other media. Another undoubted advantage is that Vector is environmentally friendly and has low process gas emissions,” said Li Naixu, chairman of Huake Casting Control (Shanghai) Technology Co., Ltd.
“Huake Casting Control Technology has become our customer as the result of the SECO/WARWICK Group’s increasing reputation in Asia. . . . We want to provide partners with solutions which will allow them to grow and achieve their intended goals related to production, quality and profitability,” said Liu Yedong, managing director of SECO/WARWICK China.
The press release is available in its original form here.
