ASTM Brass Versus JIS Brass

[TMCal]

I'm running into an issue where I have a supplier telling me that they meet my ASTM B16(H02) brass but they
are using a JIS H3250 C3604. They are very similar but the JIS brass won't anneal the same as the ASTM. The differences are as follows.

ASTM Brass
Copper - 60-63 %
Lead - 2.5-3.7%
Iron MAX .35%
Zinc - Remainder

JIS Brass
Copper - 57-61%
Lead - 1.8-3.7 %
Iron+Tin - Less than 1.2%
Iron - Less than .5%
Zinc - Remainder

So my question is, given the formula of the brass, why would the JIS brass be more difficult to anneal ?

Thanks !

 

[TVP]

Since these two standards describe hot-rolled rod, then the difference must be in the thermomechanical processing at the original mill. Have you evaluated the hot-rolled microstructure for grain size, grain size distribution, etc.?

 

[TMCal]

That's a good point. No , I have not checked the microstructure. Let me evaluate.

 

[metengr]

In addition to the above,

Iron+Tin - Less than 1.2%

This could be the key as well. Some suggested reading below

http://www.key-to-nonferrous.com/default.aspx?ID=CheckArticle&NM=98

 

[btrueblood]

Both materials have such high Zn content that they should be considered forging or hot-forming alloys (beta alloys), and so will have relatively poor cold-work capability. How are you evaluating the annealing, and why is annealing important for you?

 

[TMCal]

Everyone - Thanks.

My application will require 2 machined components to be pressed together and then rolled over to captivate one of the components. The main component must be annealed otherwise cracking of the rollover will occur. My main test is that there is no cracking so the part is functional. If there is any question then the part is tested either by a crush test or through a Rockwell hardness test.

The ASTM Brass anneals per my spec. (900 deg for 15 minutes)The JIS Brass requires that I go to 1300 deg for 25-30 minutes to get the same soft properties.