I have some (relatively cheap) stainless steel saucepans that have a
separate "skin" in contact with the hob that is attached to the base of
the main deep pressed stainless steel body by what appears to be some
sort of crude alloy "braze". It does not look to be copper based. One of
these skins has come off. Does anyone have ideas as to what the now
exposed material might contain? Because of Covid I don't have access to
my normal pool of tame (and very smart) metallurgists with their
EDAX-SEM as a last resort.

On Monday, 21 September 2020 22:35:41 UTC+1, newshound wrote:
I have some (relatively cheap) stainless steel saucepans that have a
separate "skin" in contact with the hob that is attached to the base of
the main deep pressed stainless steel body by what appears to be some
sort of crude alloy "braze". It does not look to be copper based. One of
these skins has come off. Does anyone have ideas as to what the now
exposed material might contain? Because of Covid I don't have access to
my normal pool of tame (and very smart) metallurgists with their
EDAX-SEM as a last resort.

If I have understood your description properly, it is very likely to be an aluminium alloy. Possibly with another layer sandwiching it.

This sounds like an awfully complex design for a pan to me, why would anyone
go to all that trouble in the first place?
Brian

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"polygonum_on_google" wrote in message
...
On Monday, 21 September 2020 22:35:41 UTC+1, newshound wrote:
I have some (relatively cheap) stainless steel saucepans that have a
separate "skin" in contact with the hob that is attached to the base of
the main deep pressed stainless steel body by what appears to be some
sort of crude alloy "braze". It does not look to be copper based. One of
these skins has come off. Does anyone have ideas as to what the now
exposed material might contain? Because of Covid I don't have access to
my normal pool of tame (and very smart) metallurgists with their
EDAX-SEM as a last resort.

If I have understood your description properly, it is very likely to be an
aluminium alloy. Possibly with another layer sandwiching it.

"Brian Gaff (Sofa)" wrote in message
...
This sounds like an awfully complex design for a pan to me, why would anyone go to all
that trouble in the first place?
Brian

It allows them to use thinner gauge steel basically. All pans are
shaped/drawn from single blanks and to have a heatproof base would
mean having to use thicker gauge steel for the whole pan
which would also make them considerably heavier. Instead a
heatproof base is added.

michael adams

heatproof - not subject to distortion or heat damage

On Tuesday, 22 September 2020 08:41:03 UTC+1, michael adams wrote:
"Brian Gaff (Sofa)" wrote in message
...
This sounds like an awfully complex design for a pan to me, why would anyone go to all
that trouble in the first place?
Brian

It allows them to use thinner gauge steel basically. All pans are
shaped/drawn from single blanks and to have a heatproof base would
mean having to use thicker gauge steel for the whole pan
which would also make them considerably heavier. Instead a
heatproof base is added.

michael adams

heatproof - not subject to distortion or heat damage

Some pan makers claim that the aluminium layer helps to ensure even heating and good heat transmission.

The other direction to look at this is the stainless steel protects the soft and corrosion-prone aluminium (alloy) from the food being cooked.

There are also a few pans, all of which are expensive, which use a layer of copper.

On 22/09/2020 08:59, polygonum_on_google wrote:
On Tuesday, 22 September 2020 08:41:03 UTC+1, michael adams wrote:
"Brian Gaff (Sofa)" wrote in message
...
This sounds like an awfully complex design for a pan to me, why would anyone go to all
that trouble in the first place?
Brian

It allows them to use thinner gauge steel basically. All pans are
shaped/drawn from single blanks and to have a heatproof base would
mean having to use thicker gauge steel for the whole pan
which would also make them considerably heavier. Instead a
heatproof base is added.

michael adams

heatproof - not subject to distortion or heat damage

Some pan makers claim that the aluminium layer helps to ensure even heating and good heat transmission.

The other direction to look at this is the stainless steel protects the soft and corrosion-prone aluminium (alloy) from the food being cooked.

There are also a few pans, all of which are expensive, which use a layer of copper.

As usual adams is completely wrong.

Its all about non-gas hobs - induction or radiant or plain hotplates.

Aluminium is, bar expensive copper, the best material to put in contact
for heat conduction out of a flat plate.

But it's easily damaged, so a billet is encased in stainless steel.

Pans of course are not drawn, they are spun.

--
€œThe urge to save humanity is almost always only a false face for the
urge to rule it.€�
€“ H. L. Mencken

"michael adams" wrote in message
...

"Brian Gaff (Sofa)" wrote in message
...
This sounds like an awfully complex design for a pan to me, why would anyone go to all
that trouble in the first place?
Brian

It allows them to use thinner gauge steel basically. All pans are
shaped/drawn from single blanks and to have a heatproof base would
mean having to use thicker gauge steel for the whole pan
which would also make them considerably heavier. Instead a
heatproof base is added.

Which is all ******** apparently.

Its to aid heat conductivity.


michael adams

....

On 22 Sep 2020 at 09:07:27 BST, ""michael adams""
wrote:


"michael adams" wrote in message
...

"Brian Gaff (Sofa)" wrote in message
...
This sounds like an awfully complex design for a pan to me, why would
anyone go to all
that trouble in the first place?
Brian

It allows them to use thinner gauge steel basically. All pans are
shaped/drawn from single blanks and to have a heatproof base would
mean having to use thicker gauge steel for the whole pan
which would also make them considerably heavier. Instead a
heatproof base is added.

Which is all ******** apparently.

Its to aid heat conductivity.


michael adams

...

The two purposes are not mutually exclusive. It isn't aiding heat
conductivity vertically, putting in a new layer, even highly conductive, is
not going to reduce thermal resistance vertically. It is aiding heat
conduction laterally. Partly to deliver more heat to the inside of the pan
but equally to even out the temperature across the base and reduce the
"doming" that thin saucepans rapidly develop due to non-uniform expansion.

--
Roger Hayter

newshound wrote:
I have some (relatively cheap) stainless steel saucepans that have a
separate "skin" in contact with the hob that is attached to the base of
the main deep pressed stainless steel body by what appears to be some
sort of crude alloy "braze". It does not look to be copper based. One of
these skins has come off. Does anyone have ideas as to what the now
exposed material might contain? Because of Covid I don't have access to
my normal pool of tame (and very smart) metallurgists with their
EDAX-SEM as a last resort.


Pans often have layers of metal to either spread the heat or make them
induction compatible.

Some stainless steal is induction compatible.