Switching from SS304L 1

[rwelk]

I have been looking into switching from 304L to a cheaper alternative. I noticed in MetalMickey's thread, that it was suggested to switch to SS201, SS439, or SS430Ti.

What type of applications would these materials work for? I am looking to use it on a conveyor used to move ash. The application is high temperature. We currently use SS304L, but like everyone else i'm sure, we would like to find a cheaper alternative.

 

[mcguire]

rwelk
439 has better oxidation resistance than 304 because the scale doesn't spall as much during thermal cycling. It is used for exhaust manifolds for that reason. It would have 1/3 less scale formation. 201 could be substituted, but its lower chromium level would reduce the maximum operating temperature by about 60F.
From an oxidation point of view 439 would be your best bet. You also have to consider strength, but at any temerature where 304 could be used, 439 has better strength.
The only drawback may be forming a material with 30% elongation versus one with 50%.

 

[rwelk]

mcguire,

any idea on costs of 439?

 

[mcguire]

The biggest users of 439 in the US are auto companies for exhaust systems. They get special pricing. Service centers don't carry it. It should be priced as it is in Europe at 304 price less $0.50/lb for not having 8% nickel at $6+/lb. Try a European producer such as Krupp/Thyssen or Arcelor.

 

[rmw]

edstainless can answer the question if he looks in on this thread. If he doesn't catch it by sometime late tomorrow, I will e mail it to him for him to respond to. He has answered this question privately for me before, but it was some time back, and I don't have any faith in the numbers at this time.

rmw

 

[mcguire]

It would be areal service to consumers everywhere if people shared their costs for various alloys. This is legal and ethical and would help to counter the commercial situation in which mills and service centers use prectices which give different customers different prices and generally deal in a non-transparent manner. I think many would be surprised at the under-the-table rebate deals that I have seen going on when I was with a producing mill.
If anyone is concerned with anonymity, I will be glad to act as a clearing house at mfm304@aol.com. I will pass along all information given me.

 

[EdStainless]

These are mesh belts, is the material used in the cold worked condtion for higher strength? If so this may preclude the use of 439.

439 has about the same general corrosion and pitting resistance as 304. It has better oxidation resistance and it is imune to chloride stress cracking. (though this doesn't matter to you)

Price: The base prices for 439 are slightly less than for 304, and the surcharge is a lot less. These days that would add up to a saving of ~30-40% on the material.
Now if the cost of the belts is 1/3 raw material that would save you about 10%.
In the tubing business 439 is about the same price as 304, before the surcharges are added.

= = = = = = = = = = = = = = = = = = = =
Corrosion never sleeps, but it can be managed.

http://www.trenttube.com/Trent/tech_form.htm