C844 Brass with too much Phosphorus

[AndrewTT]

UNS-C84400 Red Brass should contain .02% Maximum according to many sources online.

We have received cast parts that contain too much P (.030%-.040%). What problem(s) might this cause? I am having difficulty finding specific info. on this on the internet and we do not have an expert in-house.

The only thing I have found so far is that the extra P could cause pin holes in the castings.

Any help is appreciated.

Thank you!

 

[metengr]

Excerpts on the effects related to excess Phosphorus;

The existence of impurities and all common alloying elements, except for silver, will decrease the electrical and thermal conductivity of copper. As the amount of the second element increases, the electrical conductivity of the alloy decreases. Cadmium has the smallest effect on resulting alloy's electrical conductivity, followed by increasing effects from zinc, tin, nickel, aluminum, manganese, silicon, then phosphorus..

Phosphorus is often used to deoxidize copper, which can increase the hardness and strength, but severely affect the conductivity.

 

[WKTaylor]

Andrew TT...

Was Your casting alloy C84400 specified in the contract to meet ASTM B584? IF SO, was it CERTIFIED as having met ASTMB584 by chemical and physical testing?

IF NOT, then WHAT casting alloy specification XXX was listed in Your contract? IF SO, was it CERTIFIED as having met spec XXX by chemical and physical testing?

IF NO casting alloy spec was listed... then as TheTick once stated... "You don't get what you want... You get what you ask for. Ask carefully!” You may have gotten

Regards, Wil Taylor

o Trust - But Verify!
o We believe to be true what we prefer to be true. [Unknown]
o For those who believe, no proof is required; for those who cannot believe, no proof is possible. [variation,Stuart Chase]
o Unfortunately, in science what You 'believe' is irrelevant. ["Orion", Homebuiltairplanes.com forum]

 

[WKTaylor]

Quick NOTE.

Per MIL-HDBK-698 Copper and Copper Alloys [1971]...

Table VII QQ-C-390**- CHEMICAL COMPOSITION AND MECHANICAL PROPERTIES OF CASTING

B2(844) P is listed as high as 0.05

xxxxxx
**QQ-C-390 Canc Notice 2... QQ-C-390 was canceled and replaced by a host of specs, thus...
Refer to: ASTM B148
Refer to: ASTM B176
Refer to: ASTM B22/B22M
Refer to: ASTM B271/B271M
Refer to: ASTM B30
Refer to: ASTM B369
Refer to: ASTM B427
Refer to: ASTM B505/B505M
Refer to: ASTM B584
Refer to: ASTM B61
Refer to: ASTM B62
Refer to: ASTM B66
Refer to: ASTM B67
Refer to: ASTM B763/B763M
Refer to: ASTM B770
Refer to: ASTM B806
Refer to: SAE AMS4842E
Refer to: SAE AMS4845J
Refer to: SAE AMS4855G
Refer to: SAE AMS4860F
Refer to: SAE AMS4862F
Refer to: SAE AMS4890C


Regards, Wil Taylor

o Trust - But Verify!
o We believe to be true what we prefer to be true. [Unknown]
o For those who believe, no proof is required; for those who cannot believe, no proof is possible. [variation,Stuart Chase]
o Unfortunately, in science what You 'believe' is irrelevant. ["Orion", Homebuiltairplanes.com forum]

 

[dshore]

That Phos level is on the high side and could lead to castings with porosity or micro porosity. It will also lead to a casting defect called a misrun.

PM me if you wish to discuss in further detail.

Thanks

David Shore

 

[AndrewTT]

Thanks for the replies. Update on this situation .....the P measurement was incorrect. The parts are actually in spec. Lots of wasted energy on this end.

 

[WKTaylor]

Ahhh... "measure twice, cut once..."

Regards, Wil Taylor

o Trust - But Verify!
o We believe to be true what we prefer to be true. [Unknown]
o For those who believe, no proof is required; for those who cannot believe, no proof is possible. [variation,Stuart Chase]
o Unfortunately, in science what You 'believe' is irrelevant. ["Orion", Homebuiltairplanes.com forum]