blacksmith37
  • Member for 4 years, 9 months
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  • Huntsville, TX, United States
Is "stainless" a bulk or a surface property of stainless steel?
11 votes

"Stainless" is not a specific definition. The stainless steel with the least alloy is $5\% \; \ce{Cr}$ ( grade 501) according to AISI (It can't be cut with an oxygen/acetylene torch-like regular steel)...

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Why do we use coke instead of coal in order to reduce FeO as basic reaction in ironmaking process?
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8 votes

The single most important factor is strength ( mechanical compressive ); coal is heated to make coke, the resulting coke is stronger than the original coal. Also, coke helps to make the charge of iron ...

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Why is sea salt coarse?
7 votes

Because it is not ground as fine , unless a customer wants finely ground sea salt. It is passed over screens to separate it into sizes after grinding, just like table salt. Fun fact ; table salt that ...

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Does cold bluing steel prevent rust?
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6 votes

It provides limited corrosion protection. I would suggest just putting oil on it; more corrosion protection and it will not obscure the surface pattern which is most all that separates Damascus steel ...

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Thermal properties of 301 stainless steel
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5 votes

301 is the lowest alloy content of the "18-8" family. The slightly lower nickel ( compared to 304) makes the austenite less stable so when cold rolled it work hardens more than 304. It is ...

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Weathering steel
5 votes

To accelerate "weathering" , give it more weather - spray it with water each day . You could add a little salt ( NaCl) initially but then let the water spray remove it over time. The steel also has ...

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Why is petrol also called octane?
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5 votes

Octane is a specific molecule with 8 carbons normally found among the many different molecules in gasoline. Pure iso-octane (2,2,4-trimethyl pentane) was chosen as the reference fuel standard for ...

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Do electronic balance weighings still need to be corrected for buoyancy error?
5 votes

I think they must as the density of the material being weighed will change the correction. eg. The buoyancy of lead is much different from that of feathers.

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What replaced lead-based pigments?
4 votes

Into the 70's the better white paints were tri-metal; lead, zinc and tin (oxides). Titanium oxide (rutile) replaced the lead and the zinc and tin adjusted. The titanium has excellent hiding power so ...

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Are those magnetic iron filings in the dirt pure iron?
4 votes

More likely they were iron oxides. In moist soil ,iron/steel filings would not last more than a few weeks before turning to oxides. Now the "oxides" are not simply Fe O, Fe 2 O 3, Fe 3 O 4 , ...

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Dissolving 304 Stainless Steel
4 votes

You are not going to dissolve 304 and leave the concrete. Use sandpaper to remove the surface rust as needed : Or mechanically ( cut/grind) the 304 to remove it.

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What materials are resistant to hot chlorine?
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4 votes

Short answer — none. Hastelloy C276 or C22 are the best alloys, also considering availability, presumably cost is no object. At that high temperature there is no readily available data. At 500 °C for ...

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What exactly is the parasitic white layer that forms after iron parts are treated with ammonia?
4 votes

Steels are nitrided in ammonia gas at 900 to 1050 F ; It forms a very hard , very thin ( < 0.01 ") hard layer of iron nitride . An addition of aluminum alloy to the steel ( 0.5 to 1.0 % ) enhances ...

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Forcing a steel pipe to rust completely
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3 votes

As we in the trade say "rust never sleeps". Rust develops on the surface , rust is somewhat protective in some "weathering" steels such as Corten. Small additions of Cu ,Cr, and P ,...

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Thermal properties of aluminium alloy 6063
3 votes

American Society for Metals has many publications. Temperatures below ambient are no problem for any aluminum alloys. They are commonly used for natural gas separation liquefaction exchangers and ...

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Indicator for H2S
3 votes

Oil production areas use a personal badge; lead acetate , it darkens if H2S is present ( Draeger was a brand for detection equipment).

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Which side of an aluminum foil should I put in contact with food?
3 votes

It makes no difference; but, if the food is wet and has salt or is acidic it will corrode through in a matter of hours (at ambient temperature, not if immediately frozen). The different appearance is ...

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Is there a way to "electroplate" wood with copper?
3 votes

Using Marble's Reagent to etch stainless steel, the wood stirrer got coated with copper. Marble's is $\ce{CuSO4}$, $\ce{HCl}$ and water, but I think I added extra $\ce{CuSO4}$. This isn't ...

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Can one turn a nickel blue?
3 votes

As noted : An old nickle or new one ? Old nickles are nickle , new ones are cupronickel ( I think more like 30 % Ni , bal Cu).Quarters are clad with monel ( 70% Ni, 30 Cu). Cu has several blue ...

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What materials for a boiler, if any, do not require a deaerator?
3 votes

There are many more common alloys in the Inconel , Hastelloy , and Incoloy families. And some odd balls like MP35N, 5o:5o Cr- Ni, Vitallium , and others. Titanum won't take the heat. For all of these ...

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What metal is under the stainless layer when it wears of?
Accepted answer
3 votes

1 =no , 2= no, 3 Likely brass , 4= no. The buckle is likely a brass although the bottom edge where you polished it is copper color . That could result if you used some cleaning agent. It could be made ...

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Are coke (solid fuel from coal) and charcoal same thing obtained from different sources?
2 votes

The density and strength of coke is much higher than charcoal. Even among coals , anthracite coal makes a stronger coke necessary or very desirable for steel/iron making. Generally called "...

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What can happen to overheated aluminum cookware?
2 votes

If it did not melt or distort, then not much happens. 1100 series is more or less pure aluminum, different designations will permit different levels of tramp elements like silicon, iron, copper, etc. ...

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How to dissolve brass surrounded by aluminium?
2 votes

Not likely. Ammonium hydroxide will attack brass, but at high concentrations and not very fast. And worse, I don't easily find data for aluminium in concentrated $\ce{NH4OH}$, probably because it has ...

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Helium container
2 votes

Partial answer , helium will not diffuse through steel . Long ago I did stress rupture tests of low alloy steel at 800 F . Tests were done to evaluate if hydrogen had an affect on rupture strength. ...

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Will a titanium piercing tarnish if submerged in sulfur water (hot spring)?
2 votes

Neither Hydrogen sulfide nor sulfur dioxide will corrode titanium at ambient temperatures.

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Can iron oxide in well-point water be removed by electrolysis?
2 votes

If the plastic tank has access to air ,you do not need to do anything . Ferrous ( +2 ) is soluble in water . Ferric (+ 3) is not . So any ferric particles will settle out as oxides/hydroxides ,etc . ...

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What explains the case hardening color effect?
2 votes

Case hardening (carburizing or induction or flame) does not color steel. You are seeing “temper” colors which are unrelated to case hardening. It is caused by different thickness of very thin layers ...

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Home foundry — melting aluminum, mitigating undesirables
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2 votes

I never encountered S or C as problems in Al. The problem with hydrogen is that it can cause porosity as it is dissolved in the molten Al and comes out as a gas during freezing. Engine blocks and ...

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What can create black stains on metal after putting HCl on a tap full of limestale?
2 votes

The red is copper; the knob is likely brass , possibly bronze depending on age. Your knob is not zinc or aluminum or the HCl would have done more damage. Difficult to determine what is black and what ...

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