F13的轧件面积 式中:---直径,=(1.011~1.015),为名义直径 ∴ =(1.011~1.015)=1.013×30=30.39 ∴ F13=π×30.392/4=725.356 mm2 k3、k5、k7、k9四个道次的轧件面积为: F9 =725.356×1.15×1.15×1.25×1.3=1558.835mm2 a9=39.197mm k7 = 3269.158mm2 a7=57.18mm ...