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A Design Study in Steel - ME Elecmetal Crawler Track Shoe

AISI 4320 Modified Steel Alloy 
When a test casting was made with the heat-treated standard AISI 4320 alloy, the casting was water-quenched without cracking, but it did not meet the strength and hardness requirements in the thicker sections of the casting.

The 4320 alloy chemistry was modified with additional proprietary alloying elements to improve the hardenability.   

  • The hardness plot to the left shows the Brinell hardness values through the cross-section of the prototype shoe.  The modified 4320 does meet the hardness range required (280-320 HB).

The heat-treated, quenched, and tempered test casting with the modified AISI 4320 chemistry  was crack free, and it met the hardness and strength requirements in all sections of the casting.

The heat-treated modified 4320 alloy had a uniform martensite-bainite microstructure in all the critical sections and met the requirements for tensile strength, yield strength, and hardness.  The AISI 4320 modified is the best choice.
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Copyright 2006  by the Steel Founders' Society of America   All rights reserved. 
Address comments to: blairr@sfsa.org
Last Modified:July, 2006 by STG

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In cooperation with ME Elecmetal