need help shearing blade material selection

[sai1980]

dear all,
i am working on design & mfg. of TMT bar Cutting machine. I have problem in the material selection of shearing blade and its appropriate hardness. i have used S1 ( K455 ) material and hardness is 56 to 58 HRC. But i found failure like blade breaking and edge damages while cutting.The TMT bar Is of 60 to 80 Kg/mm2.
Can anybody will help me regarding the balde material selection and the hardness process?
Matter is too urgent. Please....

Thanks & regards,
Sainath Pohnerkar

 

[btrueblood]

TMT = ??? Thin Metal Tubing?

...and 60-80 kg/mm2 is a shear strength or lineal mass density?

...if a shear strength, is it comparable to ~85,000 psi?

How thick is the "tmt", how thick is the blade?

Shearing 85 ksi material sounds like a tough job for any tool steel...

 

[TVP]

I suggest investigating a powder metallurgy high-speed steel (PM HSS) grade such as M4 (HS6-5-4, 1.3351, SKH54) or M42 (HS2-9-1-8, 1.3247, SKH59). Contact producers like Uddeholm, Carpenter, Daido, or Hitachi. Hardness would be much higher, more like 62-66 HRC. If fracture toughness is more important than wear resistance (hardness), then perhaps look at PM cold work tool steels-- there are a number of proprietary grades from the companies that I mentioned above.

 

[arunmrao]

TMT = thermo mechanically treated. A jargon used by many steel producers in India.

 

[hydtools]

Are you sure it is a material problem and not a blade design problem?

Ted

 

[MiketheEngineer]

There are a number of shear blade mfg's out there. Just google "shear blades" and these guys can tell you exactly what you need.

Cowles and ASKO come to mind