Wednesday, September 1, 2010

[MW:6826] CuproNickel Tubes Heat Treatment -MATERIAL CUPRONICKLE 7030

Hi All

we have a situation where manufacturer of CuproNickel 7030 recommended
the below heat treat ment (ideally we should have followed word by
word)

FURNACE USED; BRIGHT ANNELING FURNACE UNDER ATMOSPHERE
TO AVOID OXIDATION
we r using crack ammonia to create NITROGEN atmosphere.

1. LOADING OF MATERIAL.
2.VACCUM THE FURNACE.
3.GAS SUPPLY on on mode AND FILL UP TO REQUIRED PRESSURE.
4.FURNACE ON.
5.RATE OF HEATING 100 DEGREE PER HOUR.
6.SOAKING TIME 400 DEGREE FOR TWO HOUR.
7.COOLING THE MATERIAL IN FURNACE UPTO 50 DEGREE.


However , we have limited facilities and our engineers suggested

1. Raise the temp of furnace to 100 deg C in empty condition to
avoid oxidation.

2. Loading of material in a "Cage" at 100 deg C . Nitrogen will
be continuously purge in "cage" to create inert atmosphere.

3. Rising of temp upto 400 deg C at the rate of 100 deg C per hour.

4. Soaking temp 400 deg C and time half hour in furnace.

5. Rate of cooling up to 100 deg C per hour upto 100 deg C.

6. After than atmosphere cooling.


My question

Is the suggested alternative viable/ close ?
what is the effect when Nitrogen is suddenly sent in a cage with 100 deg C?
can we cool the tubes from 100 deg C or we have to cool it down to 50
Deg C as suggested by the Manufacturer

I know the HT should be in reducing atmosphere , is neutral atmosphere ok ??
what are all the other available reducing media to this nonferrous job?


Thanks in advance

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No comments:

[MW:34820] RE: 34813] Clarification in Rate of heating and cooling.

Hello,   Please see the response below.   Regards.   P. Goswami, P. Eng, IWE.   From: materials-welding@googlegroups.com <materials-weld...