Welding Heat and Refractory Materials

Precaution 1: will the refractory bricks stay attached to the plate while the welding is underway?

Almost by definition, "refractory bricks" are designed to withstand high heat, thermal shock, etc.

I am a ceramic Engineer. Do you know what type of refractory you are dealing with on the welding plate? What temperature do you expect to reach during the welding process?

If you do not know, that's ok as most refractories will take very high temps in excess of twice the melting temp of the metal. remember, steel is refined in refractory lined furnaces at temps of 4000-5000 F. Most welding is concentrated heat and is quickly dissipated as the metal is a heat sink. I know it still feels very hot, but that is surface temp. The refractory can stand extremes.

The only thing that can cause a problem for you is water cooling. DO NOT cool your welds with water and get your refractory wet.

This can cause some very undesireable results. Unless it is fiber blanket, then you may be safe. Castable refractories can reimulsifie in water. Precast refractories when wet can explode when exposed to sudden extreme temperatures due to the water going from the liquid phase to the gas phase instantly and the gas is trapped with nowhere to go. I am sure you get the picture.

You may need to wait between welds or change the welding equipment. if you provide the specifics of what you are doing I may be able to provide further assistance.

Hope this helps and answers all your questions

Godspeed and have a super day, joe

Sorry, I missed the brick. the rest still applies. the type of brick can still be a factor as they are not all created equal. Do not get them wet. i should never post before my second CUP

Dear W3ig,

Thanx for a detailed reply. Your reply carries weight since you are a ceramic engineer.

The other side of carbon steel plate on which I am welding has a 50 mm thick ceramic fibre blanket of density 95 kg/cum, followed by three layers of refractory bricks of thickness 65mm,75mm and 234 mm. That is refractory bricks having dimensions 75X65X234 used in different orientations. There are no castable refractories any where near the place of welding.

Thanx once again.

Cdrgar

You are quite welcome.

I cannot imagine you having any issues welding on carbon steel with that amount of refractory on the back side of your plating. The Blanket will insulate and hold the heat of the weld which should make it easier to avoid pores from forming.

I would be astounded if you damaged the refractory in any way. I would still avoid quenching with large amounts of water. Small amounts that will vaporize on contact will not harm anything and is not likely to come in contact with the bricks in the first place. Go slow at first until you feel confident, then pour it on.

If you have any concerns, call the manufacturer of the refractory and their tech dept will advise. Wise to ask the question before proceeding. Others would have just gone ahead without giving it a second thought. At least you know what to expect now.

I spent 4 years supplying tech support as a Sales Engineer for CE Minerals to refractory companies all over North America and eastern Europe in the early 80's as my first job out of Rutgers. I really miss that business. It sure was fun.

Happy Welding, be safe, wear your gloves and goggles and have a great weekend

What will happen if refractory materials like bricks will get wet and exposed to sun then used in furnace?