Difference between hammer and press forging?

[fiddler30]

Hi to all,
Could someone explain the difference between hammer forging and press forging.
I understand the process of both methods but I need to understand more in depth the difference in structure, grain flow, hardness etc if any.
We have been successfully machining 42crmo4 Hammer forged square bar for 4 years.
Now we have to machine 42crm04 Press forged round bar, it is virtually un-machineable.
So we have the same material spec but it behaves very differently.

Can anyone help??
Many thanks

 

[jsgruszynski]

Hi to all,
Could someone explain the difference between hammer forging and press forging.
I understand the process of both methods but I need to understand more in depth the difference in structure, grain flow, hardness etc if any.
We have been successfully machining 42crmo4 Hammer forged square bar for 4 years.
Now we have to machine 42crm04 Press forged round bar, it is virtually un-machineable.
So we have the same material spec but it behaves very differently.

Can anyone help??
Many thanks

Most likely gets down to something related to http://en.wikipedia.org/wiki/Work_hardening" differences between hammer and press, and the forging temperature.

 

[mrajm]

Hi..
We have both roots for the crankshaft assembly that we manufacture.
The stock removal is lesser in case of press forged component as they more accurate in dimension but as far as machining is concerned there is a little difference between the two.
There can be something wrong with the heatreatment oe material of the components.
We will have to check that.

 

[beatricezhu]

hello,

we can machine the 42CrMo4 forged round bars.

We are a leading forged carbon, alloy and tool steel bars manufacturer from China. Now I take the opportunity to introduce our company to you.
(1) Our company profile.
We are Shijiazhuang city Qilu Special Steel Sales Co., Ltd, the sub-company of Qilu Special Steel Co., Ltd, which is a steel manufacturer founded in 1986 and located in North of Jiuguan Fly-over Bridge, Yanzhou city, Shandong province. By now, it has been one of the largest forged bars producing base in China.
We specialize in producing forged metals in different shapes and specifications. Our product quality has passed ISO9001:2008, shipping register of China, South Korea, Japan, Italy, France and so on. Being famous for its preferable quality and competitive price, our products enjoy great reputation both at home and abroad. More than 50% of our products are exported to overseas.
(2) The type of steel we can supply--- forged round bars, forged square bars, forged flat bars.
300 kinds of steel forging products in 13 series, such as alloy structural steel, alloy tool steel, carbon structural steel, carbon tool steel, bearing steel, stainless steel. Shapes---forged round bars, forged flat bars, forged square bars, forged blocks, etc.(AISI 4140, AISI 1045, AISI 4340, AISI 52100, AISI 8620, AISI 8620H, AISI4130, 34CrNiMo6, S355J2G3, 39CrNiMo3, H13, P20, 17CrNiMo6...etc.)
(3) The sizes in which we can supply above forgings.
Forged Round Bars--- Φ 80-1000mm;
Forged Square Bars--- 80-1200mm;
Forged Flat Bars-------thickness not less than 120mm.
(4) Surface---forged raw surface, peeled surface and rough machined surface

If you want to know more information about our company and products please contact me.

Contact: Alice Chuh(Ms.)
Company: Qilu Special Steel Co., Ltd
Tel: 0086 311 85373048
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Mobile: 0086 15230171102
E-mail: steel.group@hotmail.com
Skype: alicechuh

 

[alphy]

I can explain the difference between hammer forging and press forging in terms of their respective processes and resulting material properties.

Hammer forging, also known as drop forging, involves using a hammer or a mechanical press to shape a piece of metal into the desired form. This method has been used for centuries and is known for producing strong and durable parts with good structural integrity. The force of the hammer or press compresses and stretches the metal, causing it to flow and conform to the shape of the die. This results in a directional grain flow, where the metal is stronger along the direction of the flow.

On the other hand, press forging involves using a hydraulic or mechanical press to apply gradual and continuous pressure to shape the metal. This method allows for more precise control over the shaping process and can produce more intricate shapes. However, the resulting parts may have a less directional grain flow compared to hammer forging, which can affect their strength and structural integrity.

In terms of material properties, hammer forging tends to produce parts with a higher hardness and strength due to the directional grain flow. Press forging, on the other hand, may result in a more uniform hardness throughout the part. This difference in material properties may explain why the 42crm04 press forged round bar is more difficult to machine compared to the hammer forged square bar.

In conclusion, while both hammer forging and press forging are effective methods for shaping metal, they do have differences in their processes and resulting material properties. These differences can impact the machinability and overall performance of the final product. It is important to carefully consider these factors when selecting a forging method for a specific application.