Gray cast iron has () A: high compressive strength B: excellent machinability C: good casting characteristic D: all of these

To improve the machinability of low carbon steel, the heat treatment process usually used is ( ) . A: quenching B: tempering C: annealing D: normalizing

The properties of cast irons are as follows except . A: good castability B: poor mechanical properties C: good abrasion resistance D: poor machinability