CQI-9v4 Alternative TUS Testing Methods

[jimmymustang06]

I see in the new edition there is a section that allows for alternative temperature uniformity studies (P3.4.8) . If I am getting this right, it would be awesome and allow me to stress much less over the TUS that are required.

3.4.8.1: "Property" is mentioned. Can I assume this includes "mechanical properties", for the aluminum alloys we anneal?
3.4.8.1.1.2: If I'm reading it correctly, I can tensile test material that was located in the four corners and middle of our ovens every 6 months to satisfy this requirement, correct? Other than this, our frequency of tensile testing is to the ASTM requirement of "1 sample per 1,000 lbs. produced", which for us is around 2,000 tests per month.
3.4.8.1.4: We are annealing aluminum, so the acceptable "tolerances" would be the ASTM mechanical property requirements for the alloy in O-temper we are producing, I think?

Thanks in advance for clearing any of this up for me.
Jimmy

 

[pyrometry-is-life]

Hey Jimmy, what makes the TUS stressful?

In regards to your questions about CQI-9-4, here is my best effort to provide some clarification.

I see in the new edition there is a section that allows for alternative temperature uniformity studies (P3.4.8) . If I am getting this right, it would be awesome and allow me to stress much less over the TUS that are required.

Section P3.4.8 is applicable specifically in those instances where it is either impossible or impractical to insert TUS test thermocouples through or into the oven work zone (reference Section P3.4.8, Paragraph #2, pg. 60). For example, a rotary auger type oven/furnace (not possible) or certain high-temp. sinter hardening furnace systems (not practical).

If you were able to perform a TUS on the oven prior, it might be difficult to argue that the oven is no longer possible to survey. Depending on the oven, it might be possible to argue that the data from a Property Survey would be more 'meaningful' than the data obtained from a TUS performed with test thermocouples. In either instance, it would require a strong argument.

3.4.8.1: "Property" is mentioned. Can I assume this includes "mechanical properties", for the aluminum alloys we anneal?

Be careful not to interpret the term partially. Property Survey is term defined in CQI-9-4 (reference CQI-9-4, Glossary of Terms, Property Survey, pg. 109). This Alt. TUS test method is not new; it was also included/allowed in CQI-9-3. However, in CQI-9-4, the requirements and expectations for performing a Property Survey were defined more clearly and with more detail.

The requirement you've referenced here defines the intended purpose of a Property Survey. As such, remember, it is incumbent upon the Heat Treater to provide objective evidence that the thermal processing equipment is capable of consistently yielding an acceptable product.

3.4.8.1.1.2: If I'm reading it correctly, I can tensile test material that was located in the four corners and middle of our ovens every 6 months to satisfy this requirement, correct?

Additionally, a documented procedure for performing the Property Survey must exist (ref. CQI-9-4, Section P3.4.8.1.4, pg. 61) which includes a defined reaction plan to unfavorable test results. Also, the process temperature record associated with the performance of the Property Survey must objectively show that temperature was controlled within the tolerances specified in the applicable Process Table (ref. CQI-9-4, Process Table C, Item #C2.6, pg. 79). And, all Property Survey results must be documented in accordance with the reporting requirements cited in Section P3.4.8.1.6 (pg. 61).

3.4.8.1.4: We are annealing aluminum, so the acceptable "tolerances" would be the ASTM mechanical property requirements for the alloy in O-temper we are producing, I think?

The intent is for the Heat Treater to define "appropriate" tolerances for each part characteristic. Citing a tolerence specified by an applicable industry specification would be a terrific example of an "appropriate" tolerance.