Where can "casting instead of forging and iron instead of steel" be applied? explain

1, "replacing steel with iron and forging with casting" was the slogan of the Great Leap Forward (1958).

Now let me say, I will say, "You can forge but not cast, you can be steel but not iron".

3. Of course, some parts can't be forged, such as engine cylinder block and cylinder head, which must be produced by casting, and some large workpieces without batch must also be cast.

4. The most reasonable method is the lowest cost method to meet the performance requirements!