A (forged) 340 Crank is Not a (forged) 273/318 Crank?

rustyswinger said

I don't think that's quite true. Look at the link Jadaharabi posted. Casting is still done with Steel. I am not a metallurgist, but iron alone does not have the strength or harness that a crankshaft requires. I believe a crankshaft needs to be steel alloy of some kind.

Click to expand...

maybe not......

Since the invention of nodular cast iron in 1947,through the efforts of long time,the tensile strength increased to 600 ~ 900 mpa, approach or exceed the level of carbon steel.Compared with forging steel materials,nodular cast iron crankshaft not only has the characteristics of simple manufacture simple and low cost,but also shock absorption,abrasion resistance and is not sensitive to surface crack.

For high grade materials like QT800,QT900 for cast crankshaft,many cast crankshaft manufacturers also have done a lot of research experiments including alloying research is not all,often need to combine the size of the crankshaft and using iron mould coated sand,shell mold casting process such as filling pill to achieve together,and the molding process in the production of QT600, QT700 brand of the crankshaft and camshaft has a large number of applications,and become a development trend.