thyssenkrupp Steel Europe (tkSE) has given a parent company of a North American combustion company in Ohio an order to retrofit a FBA 8 combustion system.
Within the scope of a larger modernization project, thyssenkrupp Steel Europe AG (tkSE) will upgrade the combustion system of the FBA 8 galvanizing line, which is located at the Dortmund plant. The newly implemented heating system will provide drastically lower emissions.
The purchase order for delivery, assembly and commissioning of 195 modernized self-recuperative burners has recently been placed with WS Wärmeprozesstechnik GmbH. The heating system will achieve exceptionally low NOx emissions due to proven double P-tube design and the patented FLOX® combustion process. The retrofit is to be completed by mid 2022. Detailed planning will keep line down time to a minimum for the duration of the retrofit.
Dr.-Ing. Joachim G. Wünning President WS Wärmeprozesstechnik GmbH
In the future, the tkSE plant in Dortmund will operate three vertical strip lines, positioning it as an advanced and modern site for annealing and surface treating of steel strip globally. Up to 2.000.00 tons of steel can be processed annually, once all three lines are in full operation. tkSE employs and fully relies on proven and environmentally friendly heating technology. A technology that even today is suitable for a future with green combustion gases. After the conversion, approximately 800 low emissions burners will be in operation at the Dortmund facility.
WS can rely on decades of experience with the FLOX® combustion technology. Experience gained from tens of thousands of burners successfully in operation worldwide. FLOX® enables highly efficient burners to operate while simultaneously maintaining very low NOx emissions. "It is our ambition at WS," states Dr.-Ing. Joachim G. Wünning, president of WS Wärmeprozesstechnik GmbH, "to provide solutions for all continuously operated strip lines which can reliably attain NOx emissions well below 100 mg/Nm³, with simultaneously high combustion efficiency over 80% and which are, already today, suited for a future with green combustion gases."
Sometimes our editors find items that are not exactly “heat treat” but do deal with interesting developments in one of our key markets: aerospace, automotive, medical, energy, or general manufacturing. To celebrate getting to the “fringe” of the weekend, Heat TreatToday presents a Heat TreatFringe Friday with this press release which speaks to the ever evolving trends for heat treat consumers. Specifically, we are looking at a new Electric Vehicle (EV) Workgroup, but what are your thoughts? Email editor@heattreattoday.com to share your thoughts!
A new in-house working group named the Electric Vehicle (EV) Workgroup draws from Anchor Harvey’stechnological leadership and century-long experience in forging components for the automobile and motorsports industries. "We [the EV Workgroup] believe delivering high-strength, lightweight electric vehicle components," says Kerry Kubatzke, industry veteran with 35 years of experience in engineering and precision forge manufacturing at Anchor Harvey, "are core to growing our business and creating value for our customers as we work to deliver high-strength lightweight parts for the next generation of transportation."
The announcement comes as the United States, China, and European countries encourage automakers to produce more all-electric vehicles. By creating high-strength, lightweight forged aluminum components—such as steering knuckles, control arms, suspension components, structural nodes, and more—the EV Workgroup makes vehicle parts built for increased range, not range anxiety, in support of manufacturers creating the next generation of transportation.
Anchor Harvey is identifying what it takes to manufacture electric vehicles including sedans, trucks, bicycles, motorcycles, and more, to make a meaningful impact toward building a zero-emissions future. They've made investments over the past several years to incorporate cutting-edge data acquisition systems, digital monitoring processes, and preventative and predictive maintenance services, preparing them for changes in EV.
"With the introduction of our EV Workgroup," said Tom Lefaivre, president of Anchor Harvey, "we are working to push the boundaries of electric vehicle technology, manufacturing, and performance to new levels with stronger, lighter, quality aluminum components."
In a special Heat Treat Radio series, 40 Under 40 winners from the class of 2020 respond with their stories and insights of their life and work in the heat treat industry. This episode features the stories of Kelly Peters, Bryan Stern, and Andy Muto.
Below, you can listen to the podcast by clicking on the audio play button and read a few excerpts from this episode.
“I thought that this gig would buy me some time to figure out what I wanted to do when I grew up. Turns out, I grew up here in the plant, and here I am today.”
“There is so much uncertainty and less opportunity in our business at the moment. Major consumers of heat treat are at crossroads: Will the automotive industry go electric, hybrid, stay with engines, or what, and when?...So how do I run a business and plan for the future in so much uncertainty?... Just like any family, will face the challenges together and be better for them.”
“Give those favors time to mature and develop. You never know where they’ll lead unless you give them a chance.”
“Working at Solar Manufacturing [it’s been] very fulfilling; with the vacuum equipment there’s pressure vessel design, fluids, the design of the water systems, thermodynamics going into that, heat transfer, structural analysis… There’s just a lot of depth and really because it’s, in many cases, a fairly homegrown movement, there’s a lot of room for improvement.”
“From what I’ve seen with almost the disconnect between a customer and what a piece of equipment could do for them if it was applied correctly: There’s a lot of room to bring value to a customer for their process in ways that haven’t really been imagined before.”
“I originally was planning on doing my own thing after college in logistics, and did so for a number of years, but in 2014 I decided to move back home and work for Paulo.”
“What really intrigues me in the heat treatment industry is how many different applications require some form of heat treating in order for parts to perform to the necessary level that they need to in the field.”
GKN Driveline Bruneck AG (GKN) is modernizing its hardening shop with two low pressure carburizing plants, gearing up for the future as a key location for the development and production of E-powertrains in the GKN group.
For the last three years, the GKN group has been concentrating the development and European production of E-powertrains at the Bruneck site in South Tyrol, Italy. Through an extensive investment program, the site was equipped with modern production technology, placing it at the core of GKN’s E-mobility strategy. Dating back to the 1960’s, the hardening shop consists of several conventional pusher furnace systems and will now be modernized with ALD Vacuum Technologies GmbH's vacuum furnaces.
"This state-of-the-art heat treatment technology puts GKN in a position to meet the unique challenges of E-powertrain production," states Matthias John, sales engineer at ALD.
ModulTherm plant installed at GKN
In comparison with conventional combustion engine transmissions, the transmissions installed in modern electric cars are exposed to significantly higher speeds and torques. Therefore, the mechanical and metallurgical properties, as well as the dimensional accuracy of the highly stressed parts have to meet particularly high requirements. In the future, GKN intends to meet this challenge with a multi-chamber plant-type ModulTherm, and for special applications, a SyncroTherm plant. Both plants were started up in the second half of 2020.
"ALD convinced us with both, the very good results regarding metallurgical properties and low distortion of the parts. Their excellent and competent consulting reinforced us in our decision in favor of the state-of-the-art technology," explains Gianni Del Favero, value stream manager Machining and Heat Treatment at GKN. "The process combination of low-pressure carburizing (LPC) and subsequent high-pressure gas quenching (HPGQ) allows GKN to optimally adjust the parts’ properties – flexibly and component-specifically," adds John.
During the first expansion phase, in addition to the ModulTherm plant consisting of a mobile quenching module and five treatment chambers, ALD delivered fully integrated peripheral tempering and preheating furnaces, a cleaning plant, a batch buffer, and an external charge transport system.
SyncroTherm plant installed at GKN
The plant can be expanded up to 10 treatment chambers, depending on demand over the following years. Consequently, GKN will be able to gradually replace the aging protective gas furnaces.
The SnycroTherm plant will mainly be used for parts which are especially susceptible to distortion. The small batch size allows for a more targeted and finely tuned quench, resulting in little change in the dimensions of the parts.
Additionally, heat treatment of small batches enables a more flexible and faster throughput of smaller load sizes throughout the overall production.
Do you need a better system for ensuring a successful audit? Discover how a full spectrum audit of your company’s heat treat or manufacturing processing can ensure consistency, compliance, better efficiency, and cost reductions.
Today’s Technical Tuesday is an original content piece written by Bluestreak | Bright AM™ for Heat TreatToday’sAerospace Edition 2021.
Many heat treaters operate on razor-thin margins. Therefore, every part of your end-to-end process must undergo a thorough inspection for streamlining and consistency. As critical data increasingly becomes an integral part of heat treat or service-based manufacturing processing, it could be time for you to audit your end-to-end pipeline to ensure the greatest efficiency and reduce costs.
Before you get started, however, you need a robust process audit checklist to ensure consistency and compliance. Here’s what you need to know.
The Benefits of a Checklist
It’s possible to operate without a checklist at all or with a generic one designed with no particular company in mind. However, can you be sure that your audits are consistent and proactive? If you operate without a checklist, you risk consistency and compliance.
Checklists provide the following:
Consistency: Everyone evaluates the same way.
Recordkeeping: You never question when or if an audit happened.
Comprehensive reviews: You’ll never miss a detail again.
Proactive feedback: Identify issues before they become catastrophic.
Preventive maintenance: Based on feedback, you can accomplish one of the biggest success determinants in processing.
A checklist not only improves the process but also helps heat treaters make the shift to valuable proactive operations. Not many years ago, downtime due to unplanned maintenance was part and parcel of the overall process, but now it can be reduced significantly with better processing software tools, effective data capture, and statistical process control (to look for negative processing trends before they become a part-processing problem).
Building a Robust Checklist
When you shift to a checklist-based audit, it can be tempting to copy and use something generic. But that’s just too risky. Instead, think through a customized checklist that gathers the data you need and ensures a comprehensive yet efficient internal audit every single time, no matter who conducts it.
Set your schedule. Checklists only work with regular upkeep. Make sure everyone is on the same page about audit schedules.
Create your accountability line. Who reports to whom? What happens to records? Who is responsible for initiating and following up? These details matter for follow-ups and accountability.
Customize your checklist for your process. Your unique production processes aren’t exactly like anyone else’s. You can view other examples for reference, but your checklist must follow your own processes and each of the operating steps that make up each process.
Edit for length and clarity. You want a comprehensive audit, but you don’t want to exhaust your auditors. Make it easier for them to maintain audit schedules by streamlining and cutting unnecessary repetition.
Ensure that there’s room for auditor judgment. The checklist isn’t the end-all, be-all. It’s designed to guide your auditors, not erase their expertise. Make sure there’s room for this expert assessment to complement the data analytics.
The “right” checklist is highly intuitive to your production facility processes. Even one from a company in the same industry may miss crucial details from your competitive standpoint/differentiation. With a customized checklist, you assess your various processes as they stand and ensure that you’ve considered your production facility part-processing steps as the unique operation that it is.
The Process: Set benchmarks for post-audit strategies with time deadlines
Without a deadline, nothing gets done. All your benchmarks and follow-ups should have actionable deadlines. These include having proactive and preventive measures, reducing unplanned downtime, and ensuring compliance with the latest regulatory standards or part-processing specifications.
You’ll also need a plan if a timetable isn’t met. This should be part of the checklist record, so everyone involved (no matter what level) is on the same page.
Noncompliance: Ensure complete documentation and follow-through
When you have an issue of noncompliance or another failing, it’s essential to document these fully. Follow up and use that information for future improvements. This data becomes your information trail and your path forward towards continuous improvement.
It can be tempting to gloss over the recordkeeping of past failures once everything has been brought back into compliance. However, you rob your organization of the chance to streamline its process(es) and provide a roadmap for improvement in the future.
Transforming Your Heat Treating Process
A process audit checklist tailored to your specific needs is the only way to ensure that you get the data and the results you seek. You have probably gotten by in the past without it, but in a world of data-driven decision making and razor-thin margins, can you afford to now?
Think of your checklist as your process auditor’s toolbox. The checklist enhances, reminds, and ensures consistency while allowing their expertise to shine through. Once you have a customized heat treat production process audit checklist, you can reduce your risk and widen those narrow margins of success. Your business depends on it.
About the Author:Bluestreak | Bright AM™ is a Manufacturing Execution (MES) and Quality Management System (QMS) software solution to manage and control production processes and operations from front office to shipping and delivery. Ensure compliance with NIST, ISO, AIAG, API, AMS, Nadcap, SAE, TS, etc., plus any internal and Prime’s specifications. They also provide additive manufacturing solutions with Bright AM™ software.
Vacuum pumps. What are they used for? Specifically, rotary vane oil sealed vacuum pumps. What goes on inside these machines? Where did they come from? If you know what we mean by the “slap-slap” or “clack-clack” noise, can you also list the pros and cons of this feature?
In the words of today’s best of the web, “This article discusses one and two-stage ‘medium vacuum’ oil sealed rotary vane vacuum pumps that can produce a catalog ultimate vacuum of about 1 x 10-2 Torr (0.01 Torr or 10 microns) for a one stage model and about 1 x 10-3 Torr (0.001 Torr or 1 micron) for a two-stage model.”
An excerpt:
[blockquote author=”VAC AERO International” style=”1″]The last improvement that the direct drive pump has over the VBD pumps is the ability to use the oil pressure to open and close a valve at the inlet of the pump. In VBD pumps the problem of oil ‘suck back’ into the vacuum system…[/blockquote]
Maciej Korecki Vice President of the Vacuum Furnace Segment SECO/WARWICK (source: SECO/WARWICK)
An international arms and military equipment manufacturer in Brazil needed to quickly expand and was recently able to receive a new vacuum furnace to meet their manufacturing demands.
The solution was provided by the parent company to North American SECO/VACUUM, SECO/WARWICK. Their furnace, the VECTOR®, is a single-chamber vacuum furnace that uses gas quenching and can be used for multiple metal heat treatment applications and processes. In this configuration, equipped with a round graphite heating chamber, it may be used for most standard processes including hardening, tempering, annealing, solutionizing, brazing and sintering.
"A situation where we have a product almost ready to be collected is rare. This time, the customer was indeed looking for a standard solution," said Maciej Korecki, vice president of the Vacuum Furnace Segment at the SECO/WARWICK Group.
Gregg Bixler Assistant Plant Manager Elmira Heat Treating, Inc.
The scope of a heat treat controls upgrade at Elmira Heat Treating, Inc. included a new control system for a vacuum furnace. This upgrade will help the company continue their vacuum services alongside their different process offerings, including carburizing, hardening, and nitriding.
The 9220 from Super Systems, Inc. (SSI) is a robust vacuum furnace recipe based controller which is the command center for control, I/O, and redundant data logging for the processes performed on the equipment. The instrument was integrated into their existing plant-wide SuperDATA SCADA package for plant wide visibility, historical load tracking and recipe selection based on shop order part numbers.
Jim Oakes President Super Systems, Inc.
Gregg Bixler, assistant plant manager at Elmira, is familiar with SSI products in their batch IQ, temper, car bottom, and nitriding furnaces, as well as the company's SuperDATA and Load Entry software. “SSI has been great to work with, from installation and training to ongoing support. We have been using their equipment for years and the reliability, traceability and efficiency that it has given us has really streamlined our operation,” says Bixler
"We have been working with Elmira for years," says Jim Oakes, president of SSI. "Thanks to that ongoing relationship, SSI has an in-depth understanding of their needs. We look forward to continuing to provide Elmira with products that allow them to be a top-tier heat treat provider for their customers."
Canada’s Burloak Technologies will use hot isostatic press (HIP) technologies to push the limits of additive manufacturing (AM) to deliver new levels of mechanical performance and strength properties in parts for mission-critical applications. Providing rapid cooling under pressure will minimize thermal distortion and non-uniform grain growth in components, producing finished parts with optimal material properties and allowing Burloak to significantly increase production.
Peter Adams Founder and Chief Innovation Officer Burloak
As a full-service additive manufacturer, Burloak works with innovative companies in the space, aerospace, automotive, and industrial markets to rapidly transition their most challenging part designs to be additively manufactured at scale. The High Pressure Heat Treatment™ (HPHT™) capability of the new QIH 60 M URC™ HIP from Quintus Technologies facilitates this rapid transition. Combining high pressure, heat treatment, and cooling in a single process makes it possible to remove several operations from the AM production line, generating significant savings in both cost and time. Additionally, the press’s highly customizable cooling cycle can be programmed to stop at a specific temperature while maintaining the desired pressure set point.
The press's capability to rapidly cool under pressure, "is critical for Burloak as a full-service supplier for all customers, and, in particular, for the development of high-strength flight components," comments Peter Adams, founder and Chief Innovation Officer at Burloak. "Without this in-house capability, outsourcing this process would slow down our project timelines, add complexity to our processes, and risk damaging critical customer components as they would need to be shipped internationally."
The model QIH 60 press features a hot zone of 16.14 x 39.37 inches (410 x 1,000 mm), an area large enough to process any component printed on most powder bed machines, Mr. Adams notes. It operates at a maximum temperature of 2,552°F (1,400°C) and maximum pressure of 207 MPa (30,000 psi).
"We are very pleased to be chosen as their strategic partner in furthering the development of additive manufacturing," says Jan Söderström, CEO of Quintus Technologies, "and we look forward to sharing our applications expertise through our Quintus Care program."
AMS2750F? What are the new changes? How do you implement them? This informative article from Heat TreatToday's Aerospace 2021 issue will help you navigate through the uncertainty of these changes to ensure successful compliance.
This Technical Tuesday is an original content contribution from Jason Schulze, the director of technical services at Conrad Kacsik Instrument Systems, Inc. Check out other technical articles here.
Jason Schulze Director of Technical Services Conrad Kacsik Instrument Systems, Inc.
Introduction
AMS2750F has been released for approximately 7 months now. This specification applies to manufacturers and suppliers who heat treat aerospace material. AMS2750F is typically communicated via industry standards such as SAE/AMS specifications as well as customer purchase orders and part prints. This specification gets even more complex when you apply Nadcap heat treat accreditation to the equation as Nadcap has a checklist dedicated to AMS2750, which, as of January 2021, has yet to be released.
In this article we will examine some of the changes within AMS2750F as well as discuss the implementation process for suppliers.
AMS2750F Changes
General Changes
AMS2750F now has 25 tables, where there were previously 11. These tables are no longer at the end of the specification (like most SAE/AMS specifications); they are now placed throughout the specification adjacent to paragraphs to which the rewrite team thought they applied. The challenge with this is that all aspects of AMS2750 are interconnected. For example, one change in the qualified operating range of a furnace will directly affect other areas, such as instrument calibration and the temperature at which an SAT is performed.
Previously, temperature values were expressed in whole numbers. They are now expressed to the tenth of a degree (X.X°F). With this change, I would recommend suppliers follow suit in their own pyrometry procedures and associated documents: think of it as comparing apples to apples.
Scope and Definitions
The definitions section is important, especially to those who are new to AMS2750F who may be working to interpret some of the verbiage within the specification. The specification has increased the number of definitions from 79 to 87. A good example of these definition changes is the comparison of expendable thermocouples versus nonexpendable thermocouples.
EXPENDABLE SENSOR: Sensors where any portion of the thermal elements are exposed to the thermal process equipment environment.
NONEXPENDABLE SENSOR: Sensors having no portion of the thermal elements exposed to the thermal process equipment environment.
This example is especially important because it is such a major change from the previous revision of AMS2750. The definitions section within AMS2750F should be utilized often by suppliers to ensure comprehension and conformance.
Thermocouples
As simple as thermocouple technology is, there are many requirements within AMS2750F governing thermocouple usage, error, replacement, etc. Previously, AMS2750 did not address resistance temperature devices (RTDs). It now requires RTDs be nonexpendable, noble metal, and ASTM E1137 or IEC60751 (Grade A).
I do not see this next change as anything major, because what I’m witnessing in my consulting all around the US and Mexico are that suppliers already conform. Thermocouple hot junctions (the tips of the thermocouple measuring temperature) are made by either twisting, welding, or a combination of both.
In my experience, it is rare to see a thermocouple supplier/manufacturer issue a thermocouple certification that is nonconforming. Whenever there are issues with thermocouples, it is typically because the supplier did not communicate the correct information. With that, thermocouple error should be considered and communicated correctly.
Thermocouple permitted error has changed to the following:
Type R & S: ±1.0°F or ±0.1%
Type B: ±1.0°F or ±0.25%
Base metal: ±2.0°F or ±0.4%
AMS2750E permitted ±4.0°F or 0.75% for TUS, load and furnace thermocouples.
Exceptions:
Note 11: For temperatures <32°F or <0°C for Types E and T only, calibration accuracy shall meet the following:
Type E: -328 to 32°F, ±3.0°F or ±1.0 % for either, whichever is greater
Type T: -328 to 32°F, ±1.8°F or ±1.5 % for either, whichever is greater
Note 13: When correction factors are used, type B load sensors shall meet calibration accuracy of ±2.7°F or ±0.5% and types R and S load sensors shall meet calibration accuracy of ±2.7°F or ±0.25%
AMS2750 has always required that the results of an SAT and TUS must reflect corrected temperatures. This would mean when expressing the final ± readings of a TUS, those readings must be identified as corrected values. The challenge may come when you need a correction factor from a thermocouple certification where there is not a temperature value for the test. AMS2750F now addresses this situation:
PARA 3.1.4.8 - Interpolation of correction factors between two known calibration points is permitted using the linear method.
PARA 3.1.4.9 - Alternatively, the correction factor of the nearest calibration point shall be used.
PARA 3.1.4.10 - Whichever method is used shall be defined and applied consistently.
Each supplier must decide what method they will utilize and document this. Know your customer requirements; some customers may not permit certain methods.
Sensor usage has changed dramatically, especially for expendable test sensors. These thermocouples are now limited to a single use above 1200°F regardless of the type. Between 500°F and 1200°F, Type K may be used five times or three months, whichever occurs first and for Type N, 10 times or three months, whichever comes first. Below 500°F, Type K may be used for three months with no limit to the number of uses, and Type N may be used for six months, with no limit to the number of uses. I can understand how this may seem like a lot to understand and filter through, but I can assure you, we will get used to it as we did with AMS2750E.
Thermocouple certification requirements have also changed. I do not foresee any issue with this as what is listed is, for the most part, already on existing thermocouple certifications. I would advise suppliers to check the requirement in bullet point “E.” (Figure 1)
Figure 1
Instrumentation
There were several major changes within the instrumentation section. The first one is readability of furnace recording and field test instruments. Previously, readability for all furnace and field test instruments was 1.0°F; it is now 0.1°F, or to the tenth of a degree. Suppliers may find this challenging to meet as not all field test instruments on the market are capable of this. An easy way to test yours is to either source or read the value on your field test instrument at 999°F. Then, increase the temperature to 1000°F.
On some units, when a temperature is reading/sourced below 1000°F, it will show to the tenth of a degree, but when increased above a tenth of a degree, the value in the tenths place will be removed and only whole numbers will be shown. If this is the case, you will need to purchase a new field test instrument which displays values to the tenth of a degree regardless of whether values go above 1000°F.
The second major change is timers or digital clocks on recording devices. This change makes sense, as most thermal cycles used to achieve metallurgical transformation are time-dependent and have specific tolerances that apply. AMS2750F now requires that these timing devices must be accurate to within ±1 minute per hour. There is a caveat which states that as an alternative, suppliers may have a synchronized system linked to NIST via internet system which is verified monthly and will support the ±1 minute per hour requirement. With that, a new paragraph, regarding stopwatch calibration and accuracy requirements, has been inserted adjacent to the recording device timing calibration requirements.
The third change, simple and straight forward, is that the instrument number or furnace number must be stated on the calibration sticker.
Additionally, changes have been made to what is required on an instrument calibration report. (Figure 2)
Figure 2
System Accuracy Testing (SAT)
There are several changes within the SAT section that should get attention. One which may continue to be overlooked is whenever an SAT cannot be performed (not that one fails), but if no product was run and the furnace was locked out, the SAT could be performed with the first production run (AMS2750E, para 3.4.2.4). This is no longer an option. AMS2750F now states that, in this situation, the SAT must be performed prior to putting the furnace back into service (or prior to production).
Furnaces that have multiple qualified operating ranges (i.e., CL2 from 1000°F to 1600°F and CL5 from 1601°F to 2000°F) must have the SAT performed in each range, at least annually. This means that if you typically run production at 1550°F and SATs are run at the same time, at least annually, an SAT must be processed above 1600°F to catch the CL5 range.
The alternate SAT process was the source of much confusion when revision E was released. Previously, single use thermocouples (i.e., load thermocouples) did not require an SAT per AMS2750D, para 3.4.1.2. When AMS2750E introduced the alternate SAT, the wording was so poor it caused suppliers to misunderstand the requirement, and subsequent audits yielded quite a few related findings. I have written previous articles explaining the alternate SAT process in detail, so I will not be going into this topic too deeply. For information, please visit www.heattreattoday.com and search Jason Schulze.
The changes within the alternate SAT section primarily amount to clarification and incorporation of what was previously in Nadcap’s pyrometry reference guide. That being said, there really isn’t much to speak of in this section for existing Nadcap suppliers, but one item to point out is how the wording has changed. Previously, it applied to single use sensors or sensors which were replaced more frequently than the SAT frequency requirement. This has been changed to state that the alternate SAT applies to load sensors used only once. Nadcap heat treat auditor advisory HT-20-010 has clarified this further. If load sensors are used more than once, the alternate SAT does not apply, and the comparison SAT must be used.
There were some minor changes to what is required on the comparison SAT report. (Figure 3)
Figure 3
Documentation related to the alternate SAT as well as the SAT waiver have been introduced. These should be examined closely by those suppliers to whom it may apply.
Temperature Uniformity Surveys (TUS)
Among many of the changes in this section, there is one that is not stated outright but is based on verbiage changes within Tables 18 and 19 of revision F regarding frequency. In AMS2750E, Tables 8 and 9, the statement reads “Initial TUS Interval” and “Extended Periodic TUS Interval.” Due to the wording, it was assumed that if four passing consecutive TUSs were needed before going to a reduced frequency, the initial TUS would count as part of the four needed. The modified wording in Tables 18 and 19 of AMS2750F now reads “Normal Periodic Test Interval” and “Extended Periodic Test Interval.” With this change in verbiage, the initial TUS does not count toward the needed consecutive tests to reduce TUS frequencies.
If a supplier uses vacuum furnaces for thermal processes and both partial pressure and low vacuum is used, a TUS must be performed annually in the partial pressure range using the gas applied during production. This is a rather simple change, although it is important to recognize that partial pressure gases, depending on certain variables, can affect the uniformity in the area in which the gas enters the furnace.
Thermocouple location for work zone volumes less than three cubic feet has changed. AMS2750E/Nadcap previously required that the five TUS thermocouples be placed on a single plane. AMS2750F has revised this to require each test thermocouple be placed diagonally opposite of each other. Using Figure 4, this could mean suppliers may choose locations 1, 4, 5, 7, and 8 or 2, 3, 5, 6, and 9.
Suppliers familiar with GE’s P10TF3 specification will recognize this next change as it was a GE requirement long before SAE/AMS introduced it into AMS2750F. Previously, data collection during TUSs needed to start prior to the first furnace or test thermocouple reaches the lower end of the tolerance (AMS2750E, para 3.5.13.3.1). This has changed and now requires data collection to begin when the furnace and TUS thermocouples are no fewer than 100°F below the survey temperature.
The documentation or TUS certification requirements have also changed. Considering that there are so many changes within this section, I will merely point out the letter annotations that apply to changes within Para 3.5.16.1: B, D, F, G, H, J, L, O, R, S, and Y. Some of these items contain simple verbiage changes, although most of them are solid changes and should be incorporated into suppliers’ procedures and forms.
Figure 4
Rounding Requirements
Previously, AMS2750E permitted rounding in accordance with ASTM E29. To the delight of many users, I am sure, this has changed. AMS2750F now permits rounding in accordance with the following options:
All rounding must be applied in accordance with a documented procedure and used in a consistent manner.
Rounding to the number of significant digits imposed by the requirement is permitted in accordance with ASTM E29 using the absolute method or other equivalent international standards. (Previously, the only method permitted was the rounding method.)
The rounding method built into commercial spreadsheet programs is also acceptable.
All specified limits in this specification are absolute and out of tolerance test data cannot be rounded into tolerance.
Rounding must only be applied to the final calibration or test result.
Quality Provisions
The only change in this section is in regard to pyrometry service providers. The requirement now states, “Beginning 2 years after the release of this specification, third-party pyrometry service provider companies shall have a quality system accredited to ISO/IEC 17025 from an ILAC (International Laboratory Accreditation Cooperation) recognized regional cooperation body. The scope of accreditation shall include the laboratory standards and/or field service as applicable.” It is important to keep in mind that, when verifying conformance to this, the supplier’s scope of accreditation should include reference to AMS2750 with regards to instrument calibration, SAT, or TUS or all three if that is what is performed at your facility by an outside service provider.
Implementation of AMS2750F
he implementation of AMS2750F with suppliers’ systems should be two-fold: not only what is implemented but when it is implemented. Right now, AC7102/8 Rev A, as it applies to AMS2750F, is in the review stage. Its projected release date is April 2021. Regardless, once the new revision of AC7102/8 is released, suppliers will have 90 days to implement AMS2750F.
Implementing AMS2750F must be done in its entirety, not partially. This means internal procedures, forms, purchase orders, etc. should be revised in the background in conjunction with training. Once your team is familiar with the new changes, then all the revised documents should be released at one time. This ensures the whole of AMS2750F is implemented at once and not in stages.
Nadcap heat treat auditor advisory HT-20-007 requires that all thermocouples issued on or after Jan. 1, 2021 must be certified in accordance with AMS2750F. By this time, suppliers should have already revised purchase orders to require this and may have thermocouple certifications reflecting AMS2750F.
About the Author: Jason Schulze is the director of technical services at Conrad Kacsik Instrument Systems, Inc. As a metallurgical engineer with over 20 years in aerospace, he assists potential and existing Nadcap suppliers in conformance as well as metallurgical consulting. He is contracted by eQualearn to teach multiple PRI courses, including pyrometry, RCCA, and Checklists Review for heat treat.
thyssenkrupp Steel Europe (tkSE) has given a parent company of a North American combustion company in Ohio an order to retrofit a FBA 8 combustion system.
