D2 Tool Steel v ALZ H13 Steel 1

[Milkboy]

I have been with a company for 5 weeks now and I have to order some Bending Tools. Bar is heated by induction and then bent around a radius.

The drawing I have for these radiused tools state the material is D2 Tool Steel but other drawings state ALZ H13
Both sets of drawings request Hardening to 54-56 Rockwell C.

As many engineers have left and Im now the main man I cannot find any records of why some were ordered in D2 and some ordered (at a later date) in ALZ.

Im guessing ALZ was offered, and taken, as an alternative to D2 but I hoping for some advice / URLs regarding the 2 materials (price comp. / use comp. etc)

TIA



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Milkboy

 

[NickE]

both are tool steels. the D2 is an air hardening grade that has minimal dimensional change on hardening and is highly wear resistant due to the high chrome content (~12%). H13 is a "hot work" tool steel also air hardening. both can be hardened to 54-56 HRc

Nick
I love materials science!

 

[TVP]

The H13 will resist softening above 540 C better than D2. If your application works at or above this temperature, then this may be important.

 

[Milkboy]

I believe it will be above 540°C

At the risk of sounding naive, the material the tools will bend is SAE15B 35H, heated by induction to glowing red, so Im pretty sure thats well over 540°

When you say 'important' Im reading between the lines here in thinking the ALZ is better at 540 and above than D2

TIA

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Milkboy

 

[TVP]

It sounds like this application would benefit from a hot-work tool steel like H13. The resistance to thermal fatigue will also be higher for H13 than D2. Perhaps you should investigate the temperature distribution in the tool during the bending operation. This would give you a better idea of just what type of performance you need. I also realize that the company has likely "been doing it this way forever", so this may not happen, but it seems worth it to try.

 

[richardbuss]

Hi Milkboy,

the actual temperature of the material being formed/bent is usually not so important. What is important is the temperature that the tool itself is going to reach. Some tools that cut high temperature materials are cooled and have minimal contact time with the material being cut. The hardness levels you are talking about are low for D2 type material and from memory about average for H13. My guess would be your company will have used both D2 and H13 for this application. Out of interest what is the reason for failure on the tooling ?

Regards
Richard

 

[Milkboy]

Thanks Richardbuss

The tooling has not failed as such we just require
more tooling and tool holders to reduce time in changing
tools and building cetain width.

My confusion comes from the drawings which call D2 and ALZ
and the fact the guy who did this last time has left !

I have actually started a thread about the TOOL HOLDER
material in Eng Tips. This is called up as FORK STEEL on the drawing and ex-employee probably knew what it actually was.

Any suggestion as to a good tool holder material ??


TIA

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Milkboy

 

[richardbuss]

Hi Milkboy,

ALZ H13 is just a brand name from a tool steel stockist in the UK it is standard H13 material.

As already mentioned D2 is a cold work steel whereas H13 is a standard hot work steel. In some markets D2 is more expensive in others H13.

Not much help im afraid. If youd like our data sheets on H13/WNR. 1.2344 or D2/WNR. 1.2379 I could mail these to you.

Regards
Richard

 

[Milkboy]

I have found the previous material on a drawing
literally seconds ago

In the past EN24T has been used as a tool holder

It think Ill go with this (??)

Thanks



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Milkboy