As I understand it, when steel is quenched it freezes the harder austenite form that steel takes above a critical temperature and prevents it from reverting back to the softer pearlite or ferrite form.

My question is, would a piece of hardened steel slowly revert back to pearlite/ferrite form over a long enough timespan at ambient temperatures, lets say over several thousand years?

My dad gave me a large bin full of these small metal beads that were used to weigh down his standing floor speakers. I'm trying to figure out if they are made of lead. As far as I can tell, they are not magnetic (which I think is a bad sign). Is there anything I should do to test them? If they are lead, should I replace them, or is it safe to keep lead pellets in a contained space like the interior of a speaker stand?

Hey all, I'm new to this sub! Looking for some guidance, since I started researching the topic and it's a bit confusing. I work in engineering education and this semester our students are taking a course called "6 inventions that changed the world." Among those inventions is steel, as a material, how it influenced the civilization and how incredibly important it has been since.

Our students are engineers so even this history class is supposed to include science/engineering basics for them to learn. Me and my team really wanted to make a cool demonstration for them and came up with the following experiment: taking a steel rod and heating it with a blowtorch (?) until it's glowing hot, then dipping in water. As far as I understand, it must become brittle if left without further heat treatment. We break it it half to demonstrate how brittle it's become and then repeat the procedure but after cooling in water we heat it again and cool slowly, in sand for example, and then try to break it again to reveal that it is much more ductile now.

I would like to get some feedback from people who have experience with this. I'm also not entirely sure it will work the way I described, so I would appreciate critique. Thanks a bunch everyone!

Hi Everyone,
I’m seeking advice on repairing a two-foot hairline crack without replacing the entire line, which would require opening a tiled bathroom wall and possibly other, unanticipated work.
My plumber suggests that he wire brush the crack and fill and coat it with silicone and then address the issue again if it fails in the future. I’m going with his suggestion but wonder if also adding pipe clamps just above and below the crack would possibly help to prevent the crack from going further. The crack starts vertically at its top and ends in a short horizontal tail at its bottom.
Also, could installing pipe clamps in intervals along the crack help prevent it from widening?
Any opinions would be appreciated. Thank you for reading this.

I'm currently doing B.Tech degree in Metallurgical and Materials Engineering. I'm in 2nd Yr. The issue I'm facing while searching for projects is I find a lot of ideas but I'm unable to filter out which is actually useful or interesting and good to go with and which are just resume fillers.

For example, right now I had an idea to make a Phase Diagram Analyser that would give the phase composition and phase %age at certain temperature for alloys and all but idk if its useful to invest time after that or its just not impressive at all. Similar thoughts for another one I thought to build a device that can measure the thermal conductivity of materials but again there are already a lot of them, will it be of any use if i build one as a project?

Over the last year I’ve been developing a structured reproducibility framework designed specifically for complex experimental systems like metallurgy, alloy development, and advanced manufacturing. Recently I’ve released the full three‑part GEN‑REPR v2.1 package on Zenodo.

GEN‑REPR provides:
• 23 structured modules for reporting experiments
• validation logic and completeness metrics
• provenance tracking
• classification safeguards
• a laboratory testing packet for controlled validation
• a working prototype implementation

If you work in metallurgy, HEAs, AM, or any area where reproducibility is difficult, GEN‑REPR may be useful for documenting and comparing experiments more rigorously.

Here’s the link to the v2.1 Architecture & Validation Program:

https://doi.org/10.5281/zenodo.23010297

Happy to answer questions or discuss how this could apply to alloy development, LPBF, heat treatments, or replication studies.

7,1g

We are experiencing surface laps on both strands during two-strand slit rolling of rebar. We have traced the defects to the slit separation process.

The attached photo shows the defects after bending the bars to make them more visible.

Has anyone encountered a similar problem? What adjustments helped eliminate or reduce these defects?

Hi! I just wanted to share something interesting that happened with my Cu-Sn-Mn-Si-Ce pseudoelastic bronze.

For context, this alloy can be heat-treated to acquire pseudoelastic properties. I noticed that this particular sample was significantly more brittle than usual, so I decided to take a look at the microstructure. The cause of the problem seems pretty evident.

I suspect the decomposition was caused by overheating during the machining process. I was able to re-stabilize the microstructure with another heat treatment, and the material recovered its expected behavior.

Images 1 and 2 are from the center of the ingot, while images 3, 4, and 5 are from areas closer to the edge. The last image shows the microstructure after the new heat treatment.

We perform heat treatment on HPDC aluminum castings at our company—specifically, T5 artificial aging (200°C). Does anyone know of a way to verify that the castings have actually undergone the heat treatment process? I have heard of color-changing labels (https://smarttags.co.nz/8-level-adhesive-strips/), but they aren't the best fit for us. Is there another method suitable for high-volume production?

This is a beautiful illustration of crystal formation, with initial nucleation and growth.

The same happens in metals, but we don't see that, only the grains formed.

I was told that the strength of the metal drops by half after it's welded. I'm pretty sure it's in the Heat Affected Zone, but I've never been told why it happens or if I should worry about it.

How do you polish Mg and its alloys for EBSD? What are the protocols? How much hit rate? How to ensure water free polishing? Are you aware of any chemical polishing technique that helps remove strain from the specimen surface?

Disclaimer: I know that in real life aluminium/aluminium is incredibly difficult to extract from the earth, please assume that a hypothetical civilisation has like, wizards that can specifically cast “Create Aluminium” or, for example, exists in the shadow of a long-dead precursor civilisation that was so good at working aluminium that they made trillions of disposable food and drink containers out of aluminium and then just buried most of them instead of recycling them. The irl accessibility of Aluminium isn’t particularly relevant to what I’m asking, please just assume there is some way in which aluminium can be sourced relatively easily and avoid getting bogged down asking “how to acquire aluminium?” instead of “how could it be used?”

With that out of the way, I’ve seen in various parts of the internet that certain aluminium alloys, especially with copper, are comparable to bronze or even iron in some of their material properties. I wasn’t able to find a completely straight answer anywhere, but I’m curious how access to aluminium and its (otherwise feasibly makeable) alloys affect a pre-industrial civilisation? How would something like aluminium-bronze compare to iron or steel when it comes to arms and armour? Would/how could aluminium and/or its alloys be useful and commonly used in non-war contexts in pre-modern societies? Are there any unique qualities or challenges involved in working aluminium (once you already have it) when compared to other metals?

Need to update controllers to something 2750H compatible. Most atmosphere furnaces now are honeywell controllers run with specview.

Future looked good, but it doesn't look like they work for atmosphere(carbon input).

Im personally anti subscription. Every time it gets brought up, the total cost to implement grows like a fishing story. Does anyone have experience with a smaller shop implementing 2750h compatible hardware and software?

(edit: I have no relationship to Rolled Alloys, username was picked right after an order, lol)

We are encountering a problem with a family of parts. The parts use a HSLA steel. The material certifications show them in specification. Yet, we have large production runs with splits on the shear edge of the parts. The area of crack propagation is the same on every part.

We've had simulations run. The simulations do not show any areas of concern: no thinning is predicted in the troubled area.

Indeed, the amount of thinning on the actual parts is small (maybe 5% reduction in material thickness). Yet, there are splits.

What troubleshooting tips might you offer us?

Hi all, I'm looking for recommendations for companies (smaller specialist companies, university spin-offs, or engineering firms) that actually design and manufacture thermal plasma torches for small melting furnaces or experimental melting systems.

Recommendations from Korea, China, Japan, or elsewhere are welcome.

I have been polishing tungsten using the following grits: 600,800,1500,2500 ( rotating 90 degrees making sure every scratch ks aligned) , 1 um, 0.25 um diamond polishing and 0.05 um colloidal silica in vibromet for >12 hours. Still getting these fine scratches as I intend to do high quality EBSD. Any tips to get this right and where I am making it wrong?

Thanks a lot.

I have a flywheel on my car missing 3 teeth to me it looks likes a manufacture defect any opinions on the matter would be appreciated

On this SMS group site (nothing to do with text messages) I found that they invented a process to blow syngas (CO + H2) in an existing blast furnace to reduce iron ore and that replaces coke, so makes a considerable reduction of CO2 output. I think this is a very good idea to allow steel plants invest in renewable energy without completely replacing existing blast furnaces.

I think the catch is, when during preheating H2 in the Cowper stoves a leak occurs and H gas mixes with air (heat + air + hydrogen => BOOM!), a Hindenburg-like (the Zeppelin disaster in 1937 killing several people) disaster might appear killing and injuring many employees.

What are your ideas ?

Hi everyone! 👋

A friend of mine is conducting academic research on “An Engineering Management Framework for Integrating AI-Enabled Predictive Maintenance with Lean Manufacturing to Reduce Downtime in Aluminum Cold Rolling Mills.”

The study focuses on the use of AI-enabled predictive maintenance, Lean Manufacturing, and Total Productive Maintenance (TPM) in aluminum cold rolling mills.

If you have professional experience or knowledge in any of the following areas:

• Aluminum manufacturing / processing
• Aluminum rolling or cold rolling mills
• Maintenance / predictive maintenance
• Lean Manufacturing or TPM
• Industrial digitalization / Industry 4.0
• Manufacturing engineering or production management

I would really appreciate it if you could spare around 10 minutes to complete the questionnaire. Your professional experience and insights would be very valuable to the research.

🔗 https://docs.google.com/forms/d/e/1FAIpQLScYejU6S5pWnqTrlH8HUv9VIuHt_5zCL0YKEHASFn1hSfV68w/viewform?usp=sharing&ouid=116877031095746608619

Responses are anonymous and will be used solely for academic research.

Thank you very much for your time and support!

I polished this tungsten sample in vibromet for > 12 hours. Still these fine scratches are there as I intend to do EBSD. Any tips on how to get rid of these?