Glass

Decimator · 2013-09-13 11:00:42

GW Johnson wrote:

No idea what a code tag is. I'll try the periods.
Thanx,
GW

Hit quote on my previous post and look what I did. I wrapped the table in bbcode tags.

GW Johnson · 2013-09-15 16:06:33

Decimator:

Didn't you and I and Josh pal around at the recent convention?

GW

Decimator · 2013-09-15 19:13:57

GW Johnson wrote:

Decimator:
Didn't you and I and Josh pal around at the recent convention?
GW

Yep!

JoshNH4H · 2013-09-15 20:53:44

Caught red-handed making one of your infrequent posts on the Fora

But at least this shows that you're serious about your lurking

SpaceNut · 2018-02-19 20:56:37

Here is another construction material needed for the biosphere that we would want to create.
This one talks about the manufacturing process.
http://newmars.com/forums/viewtopic.php?id=225

elderflower · 2018-02-20 09:58:46

Electrolysis is used to produce high purity soft iron. The product is malleable and quite a good electrical conductor. Not good for structural work, of course.
Regular steel will be subject to brittle fracture at Mars temperatures. This phenomenon has sunk many ships on earth at temperatures a bit above freezing. Addition of alloying elements like nickel will ameliorate it. Others may make it worse. Inappropriate welding procedures have often resulted in failures, as have unsatisfactory design elements. The performance of Martian steel will depend on what alloying elements you can get your hands on.

RobertDyck · 2018-02-21 00:25:02

We'll get off-topic again. I'm not sure where to post this, so I'll just reply here.
Steels for Cryogenic and Low-Temperature Service

Carbon and alloy grades for low-temperature service are required to provide the high strength, ductility, and toughness in vehicles, vessels, and structures that must serve at –45°C and lower. Because a number of steels are engineered specifically for service at low temperature (about –100°C), selecting the optimum material calls for thorough understanding of the application and knowledge of the mechanical properties that each grade provides.
Carbon and alloy grades for low-temperature service are required to provide the high strength, ductility, and toughness in vehicles, vessels, and structures that must serve at -45°C and lower. Because a number of steels are engineered specifically for service at low temperature (about -100°C), selecting the optimum material calls for thorough understanding of the application and knowledge of the mechanical properties that each grade provides.
At temperature below ambient, a metals behavior is characterized somewhat by crystalline structure. The yield and tensile strengths of metals that crystallize in the body-centered cubic from iron, molybdenum, vanadium and chromium depend greatly on temperature. These metals display a loss of ductility in a narrow temperature region below room temperature.
The tensile strength of metals with face-centered cubic structures - aluminum, copper, nickel and austenitic stainless steel - is more temperature dependent than their yield strength, and the metals often increase in ductility as temperature decrease.
Transformation occurring in compositions that are normally stable at room temperature, but metastable at cryogenic temperatures, can greatly alter their behavior. For example, the combination of gross plastic deformation and cryogenic temperatures can cause a normally ductile and tough stainless steel, such as 301, 302, 304, 321, to partially transform to bcc structure, resulting in an impairment of ductility and toughness. A fully stable stainless steel 310 cannot be transformed at cryogenic temperatures.
The 300 series steels offer a fine combination of toughness and weldability for service to the lowest temperatures. In the annealed condition, their strength properties are adequate for ground-based equipment but inadequate for lightweight structures. For aerospace applications, fabricators can take advantage of the alloys strain-hardening characteristics and use them in highly cold-worked condition. The principal shortcomings of cold-worked materials are: low weld-joint efficiencies caused by annealing during welding and the transformation to martensite that occurs during cryogenic exposure. Selection of fully stable grade type 310, overcomes the transformation problem. Precipitation-hardening A286 stainless has even higher strength when cold worked before aging.
The only alloy steel recommended for cryogenic service is 9% nickel steel. It is satisfactory for service down to -195°C and is used for transport and storage of cryogenics because of its low cost and ease of fabrication. Other alloy steels are suitable for service in the low-temperature range. The steels A201 and T-1 can suffice to -45°C, nickel steels with 2.25% Ni can suffice to -59°C, and nickel steels with 3.5% Ni to -101°C.

Viking 2 lander recorded a low of -111°C, measuring temperature over more than a Martian year. But that's at one site. Record low recorded by Curiosity at Gale Crater was -127°C. The low I saw during the primary mission of MGS was -140°C. However, I see references that the Mars low is -153°C at the poles during winter. You wouldn't build a human base at the poles, but this does mean we don't need cryogenic steel. However, we do need steel that can withstand extreme cold. Type 310 appears to be called for.

Steel 310: I find slightly different chemical composition from different suppliers. Content as percent by weight:

Supplier          Cr        Ni      C    Mn   P     S     Si   Mo   Cu   Fe
Sandmeyer      24.0-26.0 19.0-22.0 0.25 2.00 0.045 0.030 1.50  -    -  balance
Penn Stainless 24.0-26.0 19.0-22.0 0.25 2.0  0.045 0.030 0.75 0.75 0.5 balance
AZO Materials    24-26     19-22  <0.25 <2  <0.45 <0.30 <1.5   -    -  balance

The last supplier appears to have slipped a decimal point with Phosphorus and Sulphur. However, critical alloying materials appear to be Cr, Ni, Mn. I could post properties each material give to steel, from a book I have "The Complete Bladesmith". Of course that book is from a bladesmith perspective.

Last edited by RobertDyck (2018-02-21 02:47:56)

SpaceNut · 2019-01-14 20:05:40

How to make window glass
Things that will be needed:
Glassmaker's furnace
Limestone
Silica sand
Soda
Tin

Mix the ingredients thoroughly. The exact recipe varies somewhat by application but a typical formula for soda-lime glass is 63 percent silica sand, 22 percent soda and 15 percent limestone. A typical production run might involve 1,200 tons of glass.
Pour the molten glass. Heat the mixture to 1,200 degrees and pour it through a delivery canal into a furnace that contains molten tin, so that the glass floats on top of the tin. The container of tin may be close to 50 meters long.
Let the molten glass form a smooth, even surface. The float process is so-named because the glass floats on top of the tin. Enclose the tin bath in an atmosphere of hydrogen and nitrogen to prevent gaseous oxygen from reacting with the molten glass.
Allow the molten glass to gradually cool to about 600 degrees Celsius. The glass will now be hard enough to be lifted off the molten tin and onto a conveyor belt. The speed of the conveyor belt will determine the thickness of the glass, since a faster speed will cause the glass sheets to be thinner.
Cool the glass down to room temperature. The kiln will gradually cool the glass on the conveyor belt over the course of about 100 meters. This will prevent the glass from breaking due to a sudden temperature change. The glass sheets may then be cut to any desired size.

Glass history and recipies

http://www.historyofglass.com/glass-mak … gredients/

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#26 2013-09-13 11:00:42

Re: Glass

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Re: Glass

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Re: Glass

#30 2018-02-19 20:56:37

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#32 2018-02-21 00:25:02

Re: Glass

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