BW10 vs 7% Cr Martensitic

[andysf]

Can anyone tell me what the main advantages would be of having a 7%Cr martensitic material instead of BW10?
I am aware they both have reasonable wear resistance, and suspect 7%Cr is more expensive.
Is 7%Cr a more 'castable' material?
Is there a big difference when it comes to having them in high temperature service?

 

[EdStainless]

The 7Cr alloy will have some corrosion resistance.
The natural passive film will be much stronger.
These alloys have shown good resistance to flow accelerated corrosion, corrosion/wear mechanisms, and they have better resistance to scaling at elevated temperatures.

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Plymouth Tube

 

[andysf]

Thanks kindly Ed.
Muchly appreciated.

 

[EdStainless]

It isn't really stainless, but it will not become as rough as carbon steel would.
They use a lot of 3% and 5% Cr grades in ore handling where they need material to slide against it.
So some wear resistance and corrosion resistance to the acidic run off from the ore.

7% Cr should give you decent scaling resistance to about 1200F.

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Plymouth Tube

 

[metengr]

The BW10 is a high carbon (1% by mass), manganese steel casting that would easily handle abrasive wear conditions because this material can be work hardened, and can handle impact load conditions. You really need to know the actual environment and service temperature to make a good comparison.

 

[EdStainless]

If wear is the biggest issue then stay with the BW10.
If corrosion and/or oxidation are factors then the 7% Cr will give increased performance.

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Plymouth Tube

 

[weldstan]

Expect BW10 to have superior "castability" properties.