Things you always wanted to know the answer to [Vol. 2]
Discussion
FiF said:
Willy Nilly said:
Does metal made from ore get used for different things to metal made from recycled scrap?
Well yes it does. This is because the processes lend themselves to different quantities and alloying additions. The smelting of ore into cast iron or the production of molten iron into mild steel is a very high volume process. You can also make alloying additions to produce other alloyed steel specifications but again because of the economy of scale and the massive quantities produced this means that the steel is used for products where large tonnages of the steel grade are needed, eg car body panels.
The processes which start from scrap are more expensive and are thus used for more highly alloyed steels which are not required in such vast tonnages. Even though the furnaces may be hundred tonnes per melt and more is to most of us a lot of steel it's really small stuff in the overall scheme of things.
This makes it more expensive but it is more flexible in terms of different compositional changes from heat to heat within reason. For example you don't follow a medium alloy engineering steel say a 1% Cr 0.5% Mo steel with an austenitic stainless but you could follow it with a 2-1/4Cr Moly for example.
Such steels are generally used for different applications from the high volume low alloyed steels from ore melting.
Willy Nilly said:
FiF said:
Willy Nilly said:
Does metal made from ore get used for different things to metal made from recycled scrap?
Well yes it does. This is because the processes lend themselves to different quantities and alloying additions. The smelting of ore into cast iron or the production of molten iron into mild steel is a very high volume process. You can also make alloying additions to produce other alloyed steel specifications but again because of the economy of scale and the massive quantities produced this means that the steel is used for products where large tonnages of the steel grade are needed, eg car body panels.
The processes which start from scrap are more expensive and are thus used for more highly alloyed steels which are not required in such vast tonnages. Even though the furnaces may be hundred tonnes per melt and more is to most of us a lot of steel it's really small stuff in the overall scheme of things.
This makes it more expensive but it is more flexible in terms of different compositional changes from heat to heat within reason. For example you don't follow a medium alloy engineering steel say a 1% Cr 0.5% Mo steel with an austenitic stainless but you could follow it with a 2-1/4Cr Moly for example.
Such steels are generally used for different applications from the high volume low alloyed steels from ore melting.
The electric arc furnace could if starting with the right scrap produce mild steel in theory but it wouldn't be economical to do so.
Thus in practice the two processes both make steel as in metals with an iron base but they make different compositions with different alloying additions.
These two products are used for different things.
They both might go into a car to keep the PH connection but different parts. So the first may go into the body or cast iron engine block. The more complicated engineering steel into engine and suspension components. Stainless steel might go into the exhaust or wiper blades.
It's all steel just different sorts and depending upon the analysis and the quantity and shapes you require it made by the most appropriate process.
Edited by FiF on Monday 5th May 08:08
monthefish said:
CraigyMc said:
monthefish said:
Is it illegal to sell a pint of shandy or lager-tops as a full pint, as does 'weights and measures' not dictate the minimum quantities of alcohol served?
If you bought a shandy it could be 99% lemonade and 1% beer or vice versa, as long as it added up to 568ml.The pub will have supplied exactly what you asked for.
98elise said:
monthefish said:
CraigyMc said:
monthefish said:
Is it illegal to sell a pint of shandy or lager-tops as a full pint, as does 'weights and measures' not dictate the minimum quantities of alcohol served?
If you bought a shandy it could be 99% lemonade and 1% beer or vice versa, as long as it added up to 568ml.The pub will have supplied exactly what you asked for.
I was outside having a smoke yesterday and looking at next doors front garden.
The previous tenants covered the soil with a membrane and then covered that in red whin chips.
Wherever there is a break in the membrane plants are starting to shoot.
How do plants know where to break through the surface and even which way up the surface is?
The previous tenants covered the soil with a membrane and then covered that in red whin chips.
Wherever there is a break in the membrane plants are starting to shoot.
How do plants know where to break through the surface and even which way up the surface is?
Willy Nilly said:
Does metal made from ore get used for different things to metal made from recycled scrap?
Recycled contains more copper which leads the metal to crack when its worked at lower temps. Virgin steel is easier to work at lower temps. We recycle in Cardiff and it goes I to sections and flats angle, rebar etc basically finished stuff where as port Talbot make virgin so make rolled steel for cars and the like.You can tell a higher copper rate as when the billets are hot rolled they come out with scabs and cracked edges.
We did roll stainless last year for the first time however its expensive and you have to be really selective. It doesn't take much to contaminate a pot.
neelyp said:
I was outside having a smoke yesterday and looking at next doors front garden.
The previous tenants covered the soil with a membrane and then covered that in red whin chips.
Wherever there is a break in the membrane plants are starting to shoot.
How do plants know where to break through the surface and even which way up the surface is?
Plants are programmed to seek out light and head towards itThe previous tenants covered the soil with a membrane and then covered that in red whin chips.
Wherever there is a break in the membrane plants are starting to shoot.
How do plants know where to break through the surface and even which way up the surface is?
neelyp said:
I was outside having a smoke yesterday and looking at next doors front garden.
The previous tenants covered the soil with a membrane and then covered that in red whin chips.
Wherever there is a break in the membrane plants are starting to shoot.
How do plants know where to break through the surface and even which way up the surface is?
Plants can sense the direction of gravity and so grow in the opposite direction to it. Odds are the people putting the membrane down cut holes over where they had planted the seeds but some plants are capable of growing through some pretty hard substances, bamboo for example.The previous tenants covered the soil with a membrane and then covered that in red whin chips.
Wherever there is a break in the membrane plants are starting to shoot.
How do plants know where to break through the surface and even which way up the surface is?
Carthage said:
For horse drugs (even simple wormers), we calculate the amount per kg body weight.
Why do we not do that for all human drugs, given human body weight varies as much?
Speed/safety from error, mostly. 1g paracetamol covers most of the adult population pretty well, without taking anyone unacceptably close to a possible overdose. Why do we not do that for all human drugs, given human body weight varies as much?
For kids drugs they almost always do - my daughter's on 0.4mg/kg for one of her meds, 0.1mg/kg for another.
Gassing Station | The Lounge | Top of Page | What's New | My Stuff