研究了连铸38CrMoAl钢(/%:0.35~0.42C、0.20~0.45Si、0.30~0.60Mn、1.35~1.65Cr、0.15~0.25Mo、0.70~1.10Al)夹杂物类型和形成原因。通过优化脱氧制度:提高60 t EAF终点[C
]
≥0.010%
保持高碱度渣(R≥2.5)
出钢前2~3 min向熔池喷吹碳粉
控制(FeO)
出钢过程减少Si-Fe加入量;LF喂铝线并用铝粒扩散脱氧
采用(/%)50~60CaO、10~15SiO
2
、15~20Al
2
O
3
、≤0.7(FeO+MnO)、≤5MgO高碱度渣;做好VD后保护浇铸
有效地降低钢中Al
2
O
3
类型非金属夹杂物。结果表明
优化工艺后38CrMoAl钢连浇炉数达到9炉
夹杂物废品率≤1%。
Abstract
The types and formation cause of inclusions in casting steel 38CrMoAl (/%: 0. 35 ~ 0. 42C
0. 20 ~0. 45Si
0. 30 - 0. 60Mn
1. 35 〜1.65Cr
0. 15 ~ 0. 25Mo
0. 70 - 1. 10A1) are studied. By optimizing deoxidation technique including increasing 60 t EAF end [C
]
≥ 0. 010% and maintaining high basicity slag (R≥2. 5)
injecting carbon powder in bath before tapping for 2 - 3 min and controlling (FeO)
decreasing adding Si-Fe amount during tapping; in LF refining process feeding aluminium wire and using aluminium shot for diffusion deoxidation
using high basicity refining slag (/% : 50 〜60CaO
10 - 15SiO
2
15 - 20A1
2
0
3
≤0. 7( FeO + MnO)
≤5MgO) ; and doing best shielding casting after VD process
the A1
2
O
3
types of non-metall
ic inclusions in steel is effectively decrease. Results show that with optimum process the continuous-continuous castin heats of steel 38CrMoAl are up to 9 heats