Performance of a Furnace with Kanthal A1 Heating Elements

I don't see why not....

https://www.kanthal.com/globalassets/kanthal-global/downloads/materials-in-wire-and-strip-form/resistance-heating-wire-and-strip/home-appliance_s-ka026-b-eng_lr.pdf

I'm not so sure. The link SE provided states the maximum temperature for Kanthral A1 as 1400°C. Using this for a heating element means you can have no more than a 100° temperature differential between heating element and furnace temperature.

Well I think knowing that means that the control system should be designed in such a way that it guards against overheating...maybe a slow ramp up to max temp, with redundant feedback and safety hi-temp cutout...

As regards safety arrangement a second Temperature controller is there set at just 5'C above 1300'C with the expectation that if the main temp. controller fails for any reason second controller will cut off element current .

I would go with an SCR controller...

https://www.advancedenergy.com/globalassets/resources-root/white-papers/what-you-need-to-know-about-scr-power-controllers.pdf

https://www.mtixtl.com/mtc-a5scrprecisiontemperaturecontrolunitwith30segmentsprogrammable1-5kw.aspx

Thank you for your suggestion. I shall use PID temp. controller with SCR power relay where I can use the facility of current limiter, where I can set the safe current of the heating element which will never be exceeded. I think the heating element will be amply protected by this and hope the maximum temp. of 1300'c will be reached after limiting the current.

The furnace is not a big one .It is 600mm x 600mm 900 mm . So I think 100'C temp. differential should bring uniformity of inside temperature at 1300'C after some time .I am worried if the element temperature of 1400'C for prolonged use will affect the life of the element drastically ?

Well the melting point is 1500°C, so 1400 should be ok...but you could always go with

molybdenum disilicide elements, which have a higher temperature limit...

https://www.schupp-ceramics.com/en/electric-heating.html

Among other things, you need to specify the atmosphere inside the oven. There is a big difference between running any heating element in air vs. vacuum or argon, etc.

Atmosphere is Normal air .

Only if the temperature of the elements doesn’t exceed their maximum rated temperature.

Since you are pushing near the material limits, you need some care over hot-spots and lags of the temperature sensor [location - is it in workpiece, will introduction of low emissivity workpiece raise temperature?].

Using an unsheathed (fast response) thermocouple initially is suggested, till you understand the dynamics.

Certainly precise SCR controller & estimate of thermal mass of element versus watts/current input limiter.