Maxmum amount of tin (Sn) in a H11 Steel Mold 4

[stanislasdz]

Hi

I would like to know what is the maxmum amount of tin (Sn) ca we accept in a H11 Steel mold ?

Thanks

 

[micalbrch]

I say none.

http://www.premium-stahl.de/H11.pdf

 

[stanislasdz]

Yes according to internationals standards there is no limitation but tin is very harmful. I don't know what it's the limit : 100 ppm, 200 ppm .......

Anyone have any experience on this

 

[EdStainless]

What is your limit of detection? I would want to stay low. Any Sn in the grain boundaries and you will have issues. I don't recall solubility values off hand.

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[stanislasdz]

We have a block of H11 tool steel with 350 ppm of Tin what is the risk for the customer (hot working) ?

 

[TVP]

350 ppm is an extremely high amount of Sn for a steel that will be quenched and tempered. Hot working is one concern, due to problems with hot shortness (poor hot ductility, especially in the transverse direction). A bigger concern is the poor fracture toughness and susceptibility to intergranular cracking that the final product will have. A typical limit of 100-150 ppm is used for tramp elements like Sn, Sb, and As, when using scrap-based steelmaking practices, but the highest quality steels would be specified even less than this, probably in the 10-50 ppm.

 

[stanislasdz]

Thanks TVP

As a metallurgist i would to say this block is not appropriate for our costumer but our production manager says : the product is correct because there is not a standrad for residual elments in the AISI H11 steel and the costumer dont request any maximum level of residual elements like Tin.

What the right choice ?

 

[unclesyd]

We have a lot of components made from H-11 Tool Steel that operate at 600°F and operate in a thermal cycle of RT-650°F-600°F-RT-900°F-RT. We have over a million H-11 fasteners that operate with this cycle and our spec on tramp metals especially the low volatility ones, like Sn, Pb, Zn, and Cd be essentially 0. I don't have the current spec but the old spec said non-detectable

here is some general information on tramp metals. I haven't been through it, it's hard to read on a small monitor, but it may give you some information to make decision.

http://www.jernkontoret.se/ladda_hem_och_bestall/publikationer/stalforskning/rapporter/d819.pdf

I was told long ago that if it wasn't listed there should be none. But with scrap remelting and new instrumentation there is always some of everything.

If this material was made as it should have been the vacuum processing should have gotten the Sn out.

 

[metengr]

stanislasdz;
Unfortunately, unless there is specific requirements in the purchase specification from the customer related to tramp elements, your boss is technically correct.

 

[EdStainless]

Well you boss is right until the part fails and customer shoves it back at you.
I have seen specs that list a group of such metals with a total allowed of 100ppm.

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[stanislasdz]

I am between the choice of METENGER and the choice of Ed Stainless

What the right one ?

 

[ornerynorsk]

I would reject the blank of tool steel and send it back to the vendor. Making a purse out of a sow's ear, as they say. Your material is generally the most inexpensive portion of a project, even in Eastern Europe (am I correct?) if you factor in the cost of lost customer good-will and the cost of having to do it right the second time.

 

[EdStainless]

If you send it and it fails he may never buy anything from you again. What will that cost. This stuff will probably not survive a hot working.

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