Well the problem in this very short video clip is a warped door on an older batch IQ furnace. As all experienced heat treaters know a gap of just a few thousands of an inch is going to cause exactly what you see here, namely flames leaking from around the door. Luckily the fix is pretty simple, remove the door, grind and ensure that almost perfect flatness is achieved.
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Chamber furnaces used for hardening and case hardening (carburisation followed by oil quenching) comprise a heating chamber and a directly adjacent oil bath. Depending on the design, a distinction is made between two groups:
- Furnaces based on the through quench principle (TQ furnaces)
- Furnaces based on the return through quench principle (RTQ furnaces)
In TQ furnaces, which operate according to the through quench principle, the components to be treated are loaded directly into the heating chamber, which operates above 750 °C, where they are heated up and, if necessary, carburised. The components are subsequently transported to the quenching chamber, where they are usually quenched in an oil bath. This also hardens the surface layer. The components are then removed from the furnace.
In RTQ furnaces, which operate according to the return through quench principle, the process is as follows: Here, the components to be treated are first placed in the relatively cold (approx. 120 °C to 140 °C) quenching chamber for a few minutes. After that the batch is loaded into the heating chamber, which operates above 750 °C, where it is heated up and, if necessary, carburised. Subsequently, the components are hardened in the quenching chamber, as in the TQ. The components are then removed from the furnace.
Even though the batch sizes are identical, the actual heat treatment program is the same in both furnaces and the results achieved vary only minimally, there are some differences that need to be taken into account when selecting the appropriate furnace system.
Required space and cost: The TQ furnace has both a loading and unloading door, so suitable loading systems must be installed both in front of and behind the furnace. Accordingly, this type of furnace requires more space than the RTQ furnace, which manages with only one combined system for loading and unloading. In terms of cost, the two furnaces themselves differ only insignificantly; however, since two charging systems are added to a TQ furnace, procurement is initially somewhat more expensive. However, if a line with at least 3 TQ furnaces is used for heat treatment, this investment is quickly amortised and the TQ method becomes cheaper than the RTQ method in the long run.
Treatment duration and throughput: The heat treatment program in the heating chamber is identical in both furnace systems. The difference can be found in the treatment time: This is somewhat longer in the RTQ furnace, as the charge is loaded via the quenching chamber and remains there for a short flushing duration (approx. 15 to 20 minutes). This gives the TQ furnace a slight advantage in terms of throughput, as the next batch can already be loaded into the heating chamber while the preceding batch is still curing in the oil bath. With the RTQ system it is possible that one batch could also be put into the quenching chamber while the previous batch is still in the oil bath (so-called double loading). But this is only possible if the quenching time in the oil bath is significantly longer than the purging time before loading the heating chamber. This means that with short quenching times, the furnace must first be completely unloaded before the next batch can be treated.
Maintenance and control: The TQ furnace scores here as well: During normal production it is possible to look into both the heating chamber and the quenching chamber during loading and unloading, for example to observe the condition of the brickwork or possible sooting. With a RTQ furnace, only the quenching chamber can be inspected during operation; inspecting the heating chamber is only possible when the furnace is taken out of production. The TQ furnace is more accessible for maintenance thanks to its two doors. However, it also creates a little extra work because two doors have to be monitored and inspected.
Heat treatment results and process flow: As mentioned at the beginning, the heat treatment results do not vary significantly between TQ and RTQ furnaces. Nevertheless, a few details should be mentioned: When loading the TQ furnace, air enters directly into the heating chamber. This means that the furnace atmosphere is disrupted and only builds up again after the door is closed. In the RTQ furnace, on the other hand, the batch initially remains in the quenching chamber for a short purging time. The negative effect of the air that has penetrated is compensated for there. When loading the heating chamber, no further air enters the heating chamber and the furnace atmosphere is restored more quickly.
In order to minimise the heating up time in the heating chamber, batches are often preheated to a temperature of 350 °C to 450 °C. In this case, the dwell time in the quenching chamber of RTQ furnaces would be rather detrimental, as the batches lose temperature during this time. This reduces the desired preheating effect.
In summary, it can be said that both furnace systems perform well in different areas and that one type should not be preferred over the other. If, for example, you only have limited space available, a TQ system is probably less suitable. If preheating is of crucial importance to you, a RTQ furnace does not necessarily fit into the concept. That makes individual customer requirements the deciding factor in the selection process.
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“ALD’s recent order for a single chamber high vacuum furnace with high pressure gas quenching was finalized in record time within six months. The project also included a separate vacuum tempering furnace with built-in nitriding capability and auxiliary equipment.
The equipment will be part of a wholly modernized facility for turbine manufacturing. With a pressing production start date, all units were pre-accepted including a hot test process run after as few as five months.
Many of us put our hearts and souls into making this happen. Special thanks go to our mechanics team around Andy Adler (3rd from the left), electrical engineering and commissioning – Rico Englert and Markus Kunkel (2nd from the left and rightmost respectively). Product Manager Natalie Roemer (1st from the left) as well as Vice President Heat Treatment Joachim Boss (4th from the left) accompanied the project from its very start back in 2013 to its conclusion today, and we couldn’t be prouder of the accomplishment.”
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“Ipsen’s North American Customer Service Team continues to conduct necessary in-person and remote appointments amid pandemic-related restrictions.
In January, Ipsen logged more than 150 field service visits, which included vacuum furnace installations, start-ups, relocations, hot zone replacements, annual preventative maintenance check-ins, temperature uniformity surveys, leak checks and other various troubleshooting and repair activities. The other 100 service calls, conducted by Ipsen’s technical support and sales teams, happened using remote tools such as desktop sharing and video conferencing. This is an uptick from January 2020 and from previous months.
Ipsen remains committed to making sure its customers achieve maximum uptime – especially those who supply essential products to medical technology, energy, aerospace and agribusiness to deliver vital goods and services – around the globe.
As vaccines are administered and the economy rebounds, Ipsen’s field teams continue to follow all necessary safety restrictions and protocols. Contact your Ipsen Representative to discuss your options.”
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ZF Friedrichshafen, the world’s 5th largest auto parts supplier just announced a major investment into their Gray Court, South Carolina, USA transmission facility. As can be read below the plan is to expand production of their eight-speed automatic transmission which leads to the obvious question-will this investment mean more heat treating capacity? In our humble opinion the answer is a resounding yes!
Like many automotive transmission manufacturers the company went down the road of vacuum carburizing (low pressure carburizing or LPC) a number of years ago. The end result is that this facility has two ALD “Modultherm” systems in place with a total of 16 carburizing cells and 2 Pusher lines for annealing supplied by Ipsen. Given that the company believes in keeping heat treatment in house our assumption would be that the company will expand upon what they have to accommodate increased production.
The plant opened in 2012 and became a hub for ZF’s work in large-scale transmission production, including eight- and nine-speed automatic transmissions. “As a result, we’ve been expanding our manufacturing footprint since our grand opening,” said Ashley Van Horn, a ZF spokeswoman.
Multiple North American customers have signed contracts with ZF for transmissions built at Gray Court. Van Horn said she could not disclose which automakers signed contracts. Beyond use in trucks and buses, PowerLine is “prepared for mild hybrid and plug-in variants” because it has a modular design, Christian Feldhaus, director of ZF’s commercial vehicle driveline technology unit in North America, said in the company’s announcement.”
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“Gasbarre Thermal Processing Systems is pleased to announce the opening of a 7,700 sq. ft. technical center in Livonia, Michigan. With locations in Pennsylvania, Rhode Island, and Michigan, the addition of the technical center completes another step in the process Gasbarre announced a little over a year ago to position themselves to better support their customers and advance their product offering.
The Livonia technical center will house sales, engineering, and service personnel achieving a core initiative of Gasbarre to have qualified personnel to support the large customer base in the Midwest region. Gasbarre is currently in the process of installing both atmosphere and vacuum processing equipment in the technical center to support product development, customer trials, and demonstrations.
For more information on how Gasbarre Thermal Processing Systems can manufacture custom-engineered heat treating equipment solutions for your specific thermal processing requirements, contact us at (734) 656-2000 via email at [email protected]. You can also visit our website at www.gasbarre.com and find us on LinkedIn (Gasbarre Products Inc.), Twitter (@gasproinc), and Facebook (Gasbarre Products Inc.).”
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On a regular basis we get asked; Who reads “The Monty Heat Treat News”, where these readers are and what they like reading-all information which we have at our fingertips. Lets answer the question “Who Reads The Monty Heat Treat News” first; the answer is overwhelmingly in house heat treaters first at 80%, followed by commercial heat treaters at 15% and industry suppliers and trade organizations filling out the remainder at 5%.
These numbers are exactly in line with what we would expect to see based upon estimates of how much heat treating is done in house and how much is outsourced to commercial heat treaters. In North America most estimates have in house heat treatment at 90% with the remainder outsourced, however at best this is an educated guess, worst case scenario is that this is just a stab in the dark. The discrepancy has to do with the fact that no clear definition of heat treating exists. For instance are foundries and steel mills included in captive heat treating? You pick.
Incidentally these ratios vary by region. The USA, Canada and most parts of Europe have a higher ratio of commercial vs; captive than regions such as Mexico, Indian and China. The reasons for this are many and varied but certainly ease of transportation has a great deal to do with it. More on this entire topic later.
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In the fourth Heat Treat Podcast we enjoy a stimulating conversation between Mr. Carlos Torres of furnace builder MATTSA and Mr. Steven Christopher of controls company SSi. During the conversation we learn about the basics of gas nitriding, its growth in the heat treat industry and where the technology is going. In these “bonus” pictures you see Carlos Torres Senior and Junior in one photo and Steven Christopher in a relaxed pose in the other.
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To the press release below we can add that Mr. Tim Josephs is a very experienced sales rep who in a previous life worked with another North American furnace manufacturer, AFC-Holcroft of Michigan so he brings a wealth of experience to this position. Gord Montgomery of “The Monty Heat Treat News” had this to say; “Because of the geographical size of North America direct sales people can be very expensive when both salary and expenses are included. Independent Sales Rep firms such as “Production Technologies International” are able to spread their expenses across a number of lines making them more cost effective. For this reason I would estimate that over 60% of furnaces sales on the continent are through Independent Sales Rep organizations“.
Said Tim Donofrio, Can-Eng’s Vice President of Sales, “With Mr. Josephs extensive heat treatment equipment and process experience, PTI is firmly positioned to support new customers with Can-Eng Products that provide lowest cost of ownership investments and competitive advantage benefits for the user. Can-Eng is pleased to have PTI on board to augment its sales network for this territory and looks forward to working with PTI in delivering state-of-the-art technologies to the Marketplace”.
Tim Josephs of PTI added “Having the chance to partner with Can-Eng is a great addition to our product line up. Their reputation and experience in the heat treating market will allow us to provide a first class, complete solution to our customers in the Upper Midwest. We are excited to be part of the Can-Eng family.”
About Production Technologies International, LLC: PTI is a full service manufacturer’s representative agency, based in the Metro Detroit area, providing standard and custom engineered equipment and process solutions for the manufacturing sector throughout the Upper Midwest U.S. PTI’s products include ovens, furnaces, metal finishing systems, industrial controls, automation, fixturing and material handling, dispensing systems and turnkey retrofit and installations.”
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