Drawability AISI 304 vs AISI 304L

[neesta]

Hi,

Type 304L is an extra low-carbon variation of Type 304 with a 0.03% maximum carbon content that eliminates carbide precipitation due to welding. As a result, this alloy can be used in the “as welded” condition, even in severe corrosive conditions. In many cases it eliminates the necessity of annealing weldments except for applications specifying stress relief. Type 304L has slightly lower mechanical properties than Type 304...

Regarding the last sentence... it could be said that AISI304 has better drawability vs AISI 304L due its slightly lower mechanical properties? I've heard (from comercial departmen of some stainless steel dealers) just the opposite. What do you think?

The consequences of such little differences on nominal mechanical properties (Yield strength, UTS, elongation) for each material, could be minimized in front others uncontrolled variables regarding the deep drawing processes... so, in my opinion is too hard to hold that AISI 304 drawability is better than AISI 304L drawability.

Any comments? Thanks in adance!

 

[dgallup]

If you look at the composition of 305, it has .12 carbon but I've seen it deep drawn just as well as 304L. With any of these materials I think the condition of the material is more important than the chemistry. Deep drawing quality material will have very refined grain size.

 

[neesta]

Here you've the results of Erichsen's Test extracted from stainless steeel dealer THYSSEN KROUP's technical info.

ERICHSEN TEST VALUES [mm]
Thickness 0,5 mm 1,0 mm 1,5 mm
AISI304 12 13 14
AISI304L 11,5 12 13

From where it can bee seen that for such nominal test the values are slightly higher for AISI 304 i.e. best (slighlty) drawability...

But the differences are very low so, as you say, more over chemistry, there are some other controlled and uncontrolled variables of the deep drawing processes that call in question that drawability (in a real deep drawing process) of one of them is better.

Thanks for your answer.

 

[EdStainless]

Grain size, thoroughness of anneal, and nitrogen level will have an impact as well.
I can't see a basis for making a blanket statement either way.

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[EdStainless]

In some cases high carbon 304 wild cold draw better. The carbon is an austenite stabilizer and less martensite will be formed during draw. The result will be lower strength in the as drawn condition and the ability to make heavier reductions.

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