What caused both ring dies to crack?
Could everyone help me take a look at why these two ring dies of mine cracked?
The machine is a Zhengchang 508. The ring die that has a piece blown out from the middle is made of alloy steel, and it lasted less than a month. No iron was found during inspection. The one with the crack is stainless steel, used 3 times, and no iron was found either. The compression ratio of both is 1:5. Attachments: You need to log in to download or view attachments. No account? Register
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I feel the quality is not good!
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What year was the 508 produced? The angle you took the photos from isn't good, and there's still a photo missing from the inside out, so it's hard to comment
DLG added the following content on 2009-9-7 13:32
Also, why has a large part of your carbon steel die turned black?
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Which manufacturer made the ring die?
It's better to use ring dies from big manufacturers.
For example: Zhengchang, Muyang, Shende
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The forging may have cracks,
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Is it a widened-type ring die?
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I saw this once before. Around the first crack, material blockage was severe, and the ring die would not discharge material. The pressure concentrated at the fallen-off area. If the material, heat treatment, and other aspects at the fallen-off area are not good, then force will gather at some weak point of the ring die, causing local falling-off!
Shunxi added the following content on 2009-9-7 21:01
There are many reasons for the second one, so I won't list them one by one
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I've encountered this before. A piece even fell out from the middle of a stainless steel one. I estimate there are two reasons: one is a problem with the forging, and the other is that the ring die is too thin
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The equipment is Zhengchang's. Is the die also Zhengchang's?
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Could it be that the smoothness of one plane is insufficient, causing material blockage? And that increases the pressure in the blocked area, causing the ring die to burst?
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I learned something. I still don't know much about production equipment!
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May I ask whether your model is 508 or 508D?
Our 508D also had this situation
Zhengchang's explanation was that we did not use original dies (too expensive, we can't afford them!)
---------------------
I feel the quality is not good!
---------------------
What year was the 508 produced? The angle you took the photos from isn't good, and there's still a photo missing from the inside out, so it's hard to comment
DLG added the following content on 2009-9-7 13:32
Also, why has a large part of your carbon steel die turned black?
---------------------
Which manufacturer made the ring die?
It's better to use ring dies from big manufacturers.
For example: Zhengchang, Muyang, Shende
---------------------
The forging may have cracks,
---------------------
Is it a widened-type ring die?
---------------------
I saw this once before. Around the first crack, material blockage was severe, and the ring die would not discharge material. The pressure concentrated at the fallen-off area. If the material, heat treatment, and other aspects at the fallen-off area are not good, then force will gather at some weak point of the ring die, causing local falling-off!
Shunxi added the following content on 2009-9-7 21:01
There are many reasons for the second one, so I won't list them one by one
---------------------
I've encountered this before. A piece even fell out from the middle of a stainless steel one. I estimate there are two reasons: one is a problem with the forging, and the other is that the ring die is too thin
---------------------
The equipment is Zhengchang's. Is the die also Zhengchang's?
---------------------
Could it be that the smoothness of one plane is insufficient, causing material blockage? And that increases the pressure in the blocked area, causing the ring die to burst?
---------------------
I learned something. I still don't know much about production equipment!
---------------------
May I ask whether your model is 508 or 508D?
Our 508D also had this situation
Zhengchang's explanation was that we did not use original dies (too expensive, we can't afford them!)