STRIP MAKE WAVY DURING MILLING

[PQE]

Hello , This is my firt post, sorry for eventually shortcoming.
I have very old problem, during milling process strip make wavy and i dont know what I should done in this case. I try everything: strip expansion, seasoning, change milling cutter and nothing, please help me

 

[eromlignod]

What is your material? If it is a cold-rolled metal, then it will definitely warp if you machine off the surface. This is because you are removing residual stresses at the surface that come from the rolling process, when the strip was made at the mill.

If this is the case, you'll have to change your material to a hot-rolled type, or have the cold-rolled material annealed.

Hope this helps.

Don
Kansas City

 

[PQE]

Hi, this is material spec:

Sn 3,50 - 4,50%
P 0,01 - 0,010%
Zn < 0,30%
this is not a stresses problem.
A few days ago i received test results for this strip from 2 independent institutes and result are correct, Problem is in a extension test. we controled 3 indexes:
Rp0,2
Rm
A50

test results:
strip without waving:
Rp0,2 - 583, 584
Rm - 633
strip with waving
Rp0,2 - 559,564
Rm - 608,615
i have also pictures surface of strip after milling but i dont know how i could attched to the post.
Regards

 

[ajack1]

Often if you are clamping on a flat plate the burr and swarf can be the problem. Try to clamp as near to where you are cutting as possible, even if it means moving clamps around. Also doing a pre cut run on the plate helps even offset by a small amount that way the burr and swarf has somewhere to go.

This will certainly help as does sharp cutters but will not totally eliminate the problem.

 

[PQE]

Yes you have right. We used a pre cut on the plate, but its only work when plasticity wasnt too big. We use pre cut for deleted rest of stresses our milling machine is really old and we dont use a clamping on a flat plate . Thank for support.