High-Pressure Forming Details (TDX Coated)
TDX treatment results in a slightly under-hardened substrate in most air-hardening tool steels, e.g. AISI-D2 at Rockwell “C” 54–58. The result is increased substrate toughness, which in some cases is highly desirable. However, in applications where substrate hardness is critical, post-hardening is recommended to increase the substrate hardness of TDX-treated tool steels. This provides a stronger support for the Vanadium Carbide layer (TDX treatment) which improves performance and extends tool life.
Post-hardening is especially recommended when high forming pressures are encountered. Examples include forming or drawing of heavy gauge high strength/low alloy steel and all types of heavy gauge stainless steel, roll forming of high strength/low alloy steel, most grades of stainless steels, and heavy gauge carbon steel.
The hardness of AISI-A2 or DC53 (modified D2) can be increased to Rockwell “C” 58/60 by post-hardening. High speed steels such as AISI-M2 and M4, or other powdered-metal steels can be raised in hardness to above Rockwell “C” 60 by the post-hardening service.
Post-hardening is quoted as a separate operation when it is recommended by Tool Dynamics and the TD Center. It also requires one or two additional working days on top of the normal TDX processing time. If you have any questions concerning this bulletin or would like to discuss pre-TDX machining recommendations, call us at (812) 379-4243.