Jason Schulze, Conrad Kacsik Instruments, Inc.
Introduction
Within the aerospace heat treating field, Nadcap heat treat audits are a necessary part of doing business. The requirement to obtain Nadcap approval is “flowed down” from primes like Boeing and Airbus to sub-tier suppliers and these approvals must be maintained. Nadcap heat treat audits are typically more difficult than other audits and this is due primarily to the inclusion of pyrometry.
My name is Jason Schulze. I’m a metallurgical engineer with over 20 years in the aerospace industry. I’ve been exposed to Nadcap in multiple commodities, although often focused in heat treat. I work with companies to insource and improve special processes, perform gap-analysis and internal audits as well as gain Nadcap approval. I am also contracted by PRI as an eQualern Instructor and teach multiple courses including pyrometry.
In the upcoming series of Heat Treat Today articles, I’ll present specific subjects related to Nadcap heat treat audits and pyrometry. In subsequent articles, I hope to be answering your questions – questions submitted by our readers.
In this initial article, I’ll focus on AMS2750E comprehension as well as offering a Quality based perspective with regards to accounting for each requirement within the specification.
Understanding AMS2750E
As with any specification, it must be read carefully. It would do no good to read the specification and attempt to implement it if you do not understand the material. On a scale of 1-10, with 1being zero knowledge of pyrometry, someone reading AMS2750E for the first time would need to be at least a 5 in order to properly comprehend and implement the AMS2750E Specification.
Most quality engineers are familiar with the term “bubbling” as it relates to blue prints. Bubbling a print is a practice in which each requirement is assigned a sequential number. Once this is done on the print, it is then logged onto a form which contains the designated number, its associated requirements, the subsequent result, and an accept/reject notice. Typically, this is done on machined parts that may have an intermediate process (such as heat treat) involved in their manufacture. When an intermediate process is performed, the specification is simply listed as the requirement and an accept designation is applied. The specification itself is not bubbled, but read by an engineer, and the applicable requirements flowed down.
My method is to bubble the specification itself. Take each requirement out of the specification and assign it a sequential number. Let’s call them “Characteristic Requirements”. Some paragraphs may have several requirements within a single paragraph; each would be separated and assigned its own sequential number. Let’s look at an example of this:
AMS2750E PG 19, PARA 3.4.5.1:
“The displayed temperature indication and/or recording of the sensor being tested as used in production, with appropriate offsets or correction factors, at any operating temperature, shall be compared with the corrected temperature indication of the test sensor on a test instrument”
It may seem that a single requirement is being put forward; but there are actually 7 contained within this one paragraph.
- The displayed temperature indication…
- and/or recording of the sensor being tested…
- as used in production…
- with appropriate offsets or correction factors [option for either]
- at any operating temperature…
- shall be compared with the corrected temperature indication of the test sensor…
- on a test instrument.
I have performed this task on both AMS2750D and AMS2750E. Revision E ended with 513 characteristic requirements, including tables and figures. Once bubbled, each requirement must be accounted for as they apply to your operations. For example, any requirement regarding a retort furnace would be designated “N/A” if your operation employed only vacuum furnaces. Of course, the continuing issue of comprehension arises at each step of this process. If you have a poor understanding of pyrometry it will be difficult to bubble AMS2750E, and nearly impossible to successfully complete the process of showing conformance.
AMS2750E Training
By training, I’m referring to comprehension of AMS2750E itself. Instruction on how to properly calibrate an instrument, perform an SAT or wire up a rack to perform a TUS will be much easier once AMS2750E is understood.
Several courses are offered through multiple companies. Choosing one where you will obtain practical and sound advice concerning your specific operation as it relates to AMS2750E is the key. Get pyrometry training from an engineer who not only has performed the work in accordance with AMS2750E, but more importantly, has been involved in the actual manufacturing of heat treated hardware and has been through a live Nadcap audit. Knowledge in pyrometry may be one thing; its real-time application within an actual production environment is entirely different – and invaluable.
Conclusion
Ensure your comprehension of AMS2750E is in line with Nadcap’s expectations; training will be the key. This will expedite your success in implementing AMS2750E as it applies to Nadcap.
Submit Your Questions
Please feel free to submit your questions and I will answer appropriately in future articles. Email your questions to Doug@HeatTreatToday.com.
Source: Dental Materials – 