TOOL STEEL
TECHNICAL LIBRARY
SERIES I: Introducing the Concept of Tool Steel Microstructure
SERIES II: Typical Failure Modes for Cold Work Tooling and Their Association with Microstructure
SERIES III: Basics of Heat Treatment • Part 1
SERIES III: Basics of Heat Treatment • Part 2
SERIES III: Basics of Heat Treatment • Part 3
SERIES III: Basics of Heat Treatment • Part 4
SERIES III: Basics of Heat Treatment • Part 5
SERIES III: Basics of Heat Treatment • Part 6
ZAPP HIGH-PERFORMANCE
STEEL GRADES:
TOOL STEELS
Z-TUFF PM
Z-WEAR PM
Z-A11 PM
Z-A11LV PM
Z-420 PM
HIGH SPEED STEELS
Z-M4 PM
Z-T15 PM
Z-M48 PM
Z-MAX PM
Z-M2
ZAPP PERFORMANCE PRODUCTS:
ZDM BLANKS
Effectively managing the heat treat function requires a high level of involvement with the process. Simply calling out a Rockwell hardness and sending the parts out in the first truck to arrive at the dock is not generally a recipe for success. Granted that heat treat is an inconvenient, but vital process, that occurs in the middle of the often complex steps involved in the manufacture of tooling. It is amazing, from the tool steel supplier's perspective, how often the focus becomes logistics, turnaround time, and cost with little regard for the actual metallurgy necessary for a sound heat treatment process. While one might get away with this in the case of simple components and basic commodity tool steels, it is a sure fire recipe for downstream problems for tough applications involving highly alloy, high performance grades such as powder metals. A more involved, proactive approach will result not only in more consistent results, but can also differentiate the performance of your tooling relative to competitors who may be less concerned with the heat treatment process.
The first step to ensure quality heat treatment involves careful selection of a capable heat treat source. We would offer the following five questions to ask as one attempts to qualify a vendor to provide this service.
Given the appropriate choice of a well-qualified heat treat vendor, the following list of five suggestions can be offered as steps toward maintaining close control of quality as parts go through the process.
Final comments are in fact an impassioned defense for tool steel heat treaters who take this work seriously. The first would be to allow them the time to do perform the process correctly. A typical hardening cycle in a vacuum furnace can take 4 to 6 hours, and a triple temper cycle with a thorough cool down between each can take upwards of 12 hours or more. If your expectation is the heat treater should pick up your parts up in the afternoon and return them first thing the following day, you are indicating it is acceptable for some corners to be cut in the process. Proper heat treatment takes time. Along similar lines the matter of cost needs careful consideration. Heat treat expense in most cases is a relatively small percentage of the overall cost of tooling manufacture and given the importance for tool performance, it is not an area to cut corners in order to shave a few cents off the bill. In some cases, heat treat services are where one gets what they pay for. Finally, heat treaters who have invested in new equipment and technology need a fair return on their investment and deserve the support of customers who value good, quality heat treatment.
Hopefully this has provided some food for thought for toolmakers working with outside heat treat sources. Quality heat treatment is a valuable asset for your business.
We hope you find this heat treatment series informative. Should you have any questions or comments, please send them directly to gmaddock@zapp.com.