r/metallurgy

I am working on a small constructtion project and I was wondering if 316 grade stainless steel pipes is the standard that I should be looking for when wanting to purchase pipes? From what I know 316 stainless steel has added molybdenum which helps to resist corrosion and rust much better, especially in moist and humid enviornments. But my pipes will not be used for water or plumbing but for a factory conveyer system.

I am wondering if I need to source these quality of pipes for a project that I am working on even if I don't live in a humid climate. It does rain but its not humid or moist so I am a little confuses. When I go online on sites like alibaba or amazon business there are a lot of different qualtiies of pipes but a lot of them are labelled at 316 grade stainless steel pipes.

Hi everyone,

I have a unique (hopefully) corrosion issue that I am looking for some input. I recently ran some corrosion tests on a very simply organic solvent (very common) + aqueous HCl system ( HCl is about 2wt% and lower, total mass basis). I tested metal coupons (316L SS, HC-22, HC-276, and Ultimet Cobalt 6B). All of the coupons corroded at 50C (1-30days) and the microscope images show what could be intergranular corrosion (like I can see the grain boundaries). I want to test if there is any other metals and alloys that can withstand this solution. I have Titanium Gr 2, 5, 7 and Inconel 625, 600, Monel 400, that I have not tested but from what I can find maybe only Titanium has good corrosion resistance out of these.

All responses appreciated. Thanks in advance.

I [F17] posted on here last time if I should do a CNC machinist or welding apprenticeship, I finally got my offers this week. I mentioned that I was interested in metallurgy to one of the companies that happened to have a metallurgist.

They extended a apprenticeship position specific to metallurgy just for me!! I’M SO EXCITED YAY!!!

Im designing and making my own Hex, Torx and Penta Bits to be made into custom socket sets, maybe potentially into my own small brand.

I want to do some materials science and break some batches of different potentially exotic metals.

Ill have them EDM cut to get the best accuracy and after selecting the strongest alloy ill do selections for coatings/surface protection if necessary.

I’ve been working as a materials engineer for the past 3 years at a testing lab, and I’ve gotten to work with our failure analyst a few times on projects. Now I’m really interested in pursuing FA, but I don’t know where to start. Any advice?

So I know copper itself has glomming issues But do you know if tin or aluminum bronzes have the same issue? I am doing a long process of making a very special pen and I have to thread it so I just wanna know what I'm getting into

If immersion ultrasonic testing is calibrated using a 0.2 mm flat bottom hole reference, and the tested steel sample shows a reflection amplitude "echo " 50% ,does that mean the defect size is 0.1 mm?

I don't think the reflected amplitude percentage directly gives the defect size, because the defect could be a pore or non metallic inclusion, which would produce different reflection amplitude even if they have the same size. The orientation also influences the amplitude.

So, what reliable information does the reflection percentage actually provide??

I am currently designing a new blasting station for a company that manufactures agricultural seed hoppers/trailers made mainly from SAE 1020 steel.

The objective of the process is only surface preparation before painting (rust/scale removal and good paint adhesion). The company currently uses conventional sand blasting, but we are evaluating switching to a reusable abrasive system with abrasive recovery and recycling.

We are considering steel grit as the abrasive, mainly because of its reusability and because it seems suitable for generating a good anchor profile for paint. We also want to move away from traditional sand blasting because of the ventilation and dust problems it generates.

Does steel grit sound like the right choice for this application, or would you recommend another abrasive/media instead? Also, what grit size would you recommend for this type of paint-preparation work on SAE 1020 steel?

We're a well drilling company that uses custom-built downhole casing cutters to cut off steel pipe below grade. The steel being cut is typically mild pipe steel, but can be stainless 304, or High Strength Low Alloy (HSLA) steel pipe.

The tools we're using were all built by machinists that have long passed away, and we find ourselves in the position of needing to get new blades built. These blades look like most pipe cutting blades (Reed MFG Products for example), but we don't know what metal was used to make them or how it was hardened.

We've taken the spare blades we have to a machine shop and they are recommending either H900 17-4 stainless for 42 HRC, heat treated tool steel for 50 HRC+, or destructive lab testing to verify.

I'm looking for input here for what steel product might be best used to build these blades. We could send in for destructive testing, but I'm thinking this is overkill - someone out there must know what a typical cutting blade would be made from.

Anyone?

I am installing a 3.5 kW solar system on the rooftop of a 4-floor building in a Hot semi-arid monsoon climate

I have been given the option between a welded structure and a nut-bolt structure. Hot-dip GI 100x50x2mm welded structure OR hot-dip GI structures with 80x40x2mm Nutbolt structure both of 80 micron.

Based on pnline, I found that nut-bolt structures are considered superior, however most local vendors are strongly suggesting the welded structure, claiming that nut-bolt structures vibrate and need re-fastening every 5 years or so.

Which one would be preferred based on your real-world experience?

Someone also suggested using pure SS 304 fasteners with Nylock nuts and spring washers for the nut-bolt structure (is this good or is their a better combination?)
There is also Nord-Lock which is known for superior vibration resistance would Nord-Lock actually be beneficial for a 3.5 kW structure or would it be overkill?

(extra info: The vendor will be installing M20 cement blocks on each pillar as the base foundation )

Please also suggest any other factors I should consider or precautions I should take for this type of installation.

I need to cut samples from a tube with a colmonoy overlay that is 17% tungsten. I'm wondering what would be the best way to go about cutting this material cleanly for mounting in a 1.5" press and polishing. Sorry if this isn't the place to be asking, I'm running out of options.

Hi all, my advisor wants me to look into ways I can change our manual grinder-polisher (Buehler EcoMat30) to a semi automatic.

The samples I'm polishing are 10 mm in diameter and have strict perpendicularity requirements. The have already been properly machined to these requirements , I just need better surface quality now. There is a worry that by hand polishing I'll introduce like edge rounding or uneven pressure so the surface doesn't remain truly flat.

I am looking for like a mount or holder system that I can use with my manual polisher to keep the surface flat. Do y'all have a suggestion? Has anyone made a rig themselves for this type of application?

It should also be noted that I cannot permanently mount the specimens in carbon/graphite/resin and both sides of the specimen needs to be polished

Hi

is anybody here whos into extractive metallurgy like pyrometallurgy, hydrometallurgy, biohydrometallurgy, metallurgical assaying or metallurgical accounting, typicaly in gold in ores