woodburner steel

[cornish wood burner]

The steel or cast debate has reminded me that I need to source some steel plate to repair our large chip wood burner. The problem is the plate that supports the cast grates is corroded and buckled.

Would the plate from a good quality stove manufacturer survive and would they sell me a piece assuming it would be good enough. It would run cooler than the cast grate but Im sure it needs to be better than mild steel.

[arboriculturist]

The steel or cast debate has reminded me that I need to source some steel plate to repair our large chip wood burner. The problem is the plate that supports the cast grates is corroded and buckled.

Would the plate from a good quality stove manufacturer survive and would they sell me a piece assuming it would be good enough. It would run cooler than the cast grate but Im sure it needs to be better than mild steel.

 

Buy from a Steel Stock-holder, as will be 1/2 the price.

 

Many offer a cutting service.

 

Buy double the steel thickness you have now.

 

They will advise , which grade appropriate. Good luck:001_smile:

[agg221]

If Lloyd at stainlessandaluminium.co.uk can get you some 441 or 444 grade then this would be what I would use.

 

Alec

[cornish wood burner]

Buy from a Steel Stock-holder, as will be 1/2 the price.

 

Many offer a cutting service.

 

Buy double the steel thickness you have now.

 

They will advise , which grade appropriate. Good luck:001_smile:

My special steel supplier has now been taken over and head office didn't offer any suggestions. I don't think Bristol offices are very interested in Cornwall. Probably 8x4 sheets would be the only option for boiler plate.

 

Thickness is limited by the slot in the grates unfortunately.

[cornish wood burner]

If Lloyd at stainlessandaluminium.co.uk can get you some 441 or 444 grade then this would be what I would use.

 

Alec

Thanks Alec

I was tempted with stainless. Possibly overkill but do it once and all that. The only thing that I am hesitant on is the coefficient of expansion. It will be part of a retort and quite severely constrained so if it expands more than the original then might give a distortion problem. I don't carry the figures in my head but I seem to remember from long ago that some stainless can expand quicker than lesser steels. I will need to research this.

[arboriculturist]

My special steel supplier has now been taken over and head office didn't offer any suggestions. I don't think Bristol offices are very interested in Cornwall. Probably 8x4 sheets would be the only option for boiler plate.

 

Thickness is limited by the slot in the grates unfortunately.

 

There are several online - we even get Hardox profiles cut.

[cornish wood burner]

There are several online - we even get Hardox profiles cut.

 

Thanks I will do a bit of searching. Problem is I don't know what the boiler manufacturer used originally. Would be good to upgrade slightly. Might bite the bullet and try a bit of 441 as Alec suggested

[arboriculturist]

Thanks I will do a bit of searching. Problem is I don't know what the boiler manufacturer used originally. Would be good to upgrade slightly. Might bite the bullet and try a bit of 441 as Alec suggested

 

They know their products and give good advice.

[agg221]

Thanks Alec

I was tempted with stainless. Possibly overkill but do it once and all that. The only thing that I am hesitant on is the coefficient of expansion. It will be part of a retort and quite severely constrained so if it expands more than the original then might give a distortion problem. I don't carry the figures in my head but I seem to remember from long ago that some stainless can expand quicker than lesser steels. I will need to research this.

 

441 and 444 are ferritic grades. These have much lower expansion than the more 'normal' 304 or 316 (A2 or A4) austenitic grades. Expansion is comparable to mild steel. Specifically, coefficients of thermal expansion are (approximately, as they are non-linear):

 

Grey cast iron: 11-15

Mild steel (and other carbon steels): 12-14

Ferritic stainless (400 series): 9-12

Austenitic stainless (300 series): 16-18

 

This is why I suggested the ferritic grades. Note, they are also usually a lot cheaper than the austenitics as they don't contain nickel. There are large quantities of them used in steam pipes and boiler parts in power stations (although these are usually 9-Cr, but I haven't previously been able to find a stockholder who carries this). The chromium gives corrosion resistance and good high temperature strength, niobium and titanium give creep resistance.

 

Alec

[cornish wood burner]

Hi Alec

I did a spend a little time researching this afternoon and having two grades to look at really helped. Very relieved about the expansion on the ferritics and the cost can do no harm either. Absolutely top notch advice and information, thank you very much.