With the process measures including in LF refining process using 0. 004% Ti medium carbon manganese iron and 0. 012% Ti low titanium chromium iron for adjusting alloy content in steel and using amount of 0. 3%Ti silicon-car- bide ≤10 kg/heat
using high basicity refining slag (/% ) : 50 ~55CaO
5 - 8SiO
2
27 ~ 31 Al
2
O
3
7MgO
≤ 0.8( FeO + MnO) and feeding sulfur wire
the chemical composition of 4 heats steel 16MnCr5 is stable i. e. /% : 0.17 ~ 0.19C
0.12 ~0.16Si
1.15 ~ 1.16Mn
0.012 -0.016P
0.026 〜0.030S
0.93 ~0.96Cr
0.007 ~ 0.008Ti
0.0006 ~ 0.0008B
0.026 ~0.030Alt
0. 0013 ~0.0025O)
the rating of inclusions in steel is A thin series ≤2.0
A heavy series ≤1.5
other ≤l.0
the rating band structure in steel is ≤ 2.0 and the hardena
bility band width △ HRC scale ≤ 6 to meet the requirement of technical specification.