Customer Questions: The difference between steel plate and forgings
Our company produces a class of products, one of which is S22253III (standard NB//T47010-2017 ) material, and the finished product is obtained after machining.
However, this disadvantage is that the metal material cost is very high, and many materials will be cut off during the machining process. By querying the GB / T24511-2017 standard, the steel plate of material S22253 can be found. The comparison table of chemical elements and mechanical properties in the two standards is as follows:
| C | Si | Mn | Cr | Ni | Mo | N | P | S | Forgings |
| 0.3 | 1 | 2 | 21-23 | 4.5-6.5 | 2.5-3.5 | 0.08-0.20 | 0.03 | 0.015 |
| C | Si | Mn | Cr | Ni | Mo | N | P | S | Steel Plates |
| 0.03 | 1 | 2 | 21-23 | 4.5-6.5 | 2.5-3.5 | 0.08-0.20 | 0.03 | 0.015 |
| Rm | Rp0.2 | A | HBW | HRC |
| 620 | 450 | 25 | / | / |
| 620 | 450 | 25 | 293 | 31 |
By comparing the chemical elements and mechanical properties, the forgings are basically the same as the steel plate, and the steel plate has more hardness requirements. Other requirements in the standard basically do not affect the performance. Then, can the steel plate be used instead of forgings?
A certain thickness of steel plate is used for machining, which will be much lower in terms of raw material cost. Secondly, the steel plate can also be cold-worked before machining so that its shape is more conducive to processing, thereby reducing the amount of machining, which can save a part of the cost.
However, in theory, forging can eliminate defects such as as-cast porosity produced by the metal in the smelting process and optimize the microstructure. At the same time, because the complete metal streamline is preserved, the forging should have better mechanical properties. However, from the standard requirements, it needs to reflect the superior performance of the forging.
Please also provide high guidance; thank you!
Viewpoint 1:
The fiber flow direction inside the forging is similar to the final shape, which will have an enhancement effect.
For gaining forging shape, the processing allowance should be manageable. On the contrary, with the steel plate, the place where the material is removed needs to be processed and removed, and the processing margin will be much larger.
As for the mechanical properties that cannot meet the requirements of use, light theory does not work directly to do a small batch, 5 pieces, 10 pieces, direct test is still ongoing.
Viewpoint 2:
Boeing aircraft beam ribs and other traditional are forgings, later changed into thick plate carvings. The structure is lighter, the riveting parts are greatly reduced, and the static strength is improved. The cost is particularly reduced.
The only reason is that the fatigue life is reduced, so now 737 and that year, the life is reduced.
