摘要
采用25t EAF-LF-VOD-浇注电极-电渣重熔工艺生产的6吨Hastelloy G3电渣锭,锻造成∮350 mm圆棒时,表面出现大量裂纹。为研究裂纹产生原因,在锻棒不同位置进行取样分析气体、夹杂物,并通过扫描电镜对裂纹缺陷进行观察,对缺陷组成进行成分分析。分析结果表明,裂纹产生原因是由于电渣重熔过程熔速较快,导致电渣锭氧含量高,大量脆性夹杂物在晶界聚集析出,使材料热塑性变差,在锻造过程中产生裂纹。通过采用(%)CaF_(2):Al_(2)O_(3):CaO=75:15:10渣系代替原有(%)CaF_(2):Al_(2)O_(3)=70:30渣系,电渣熔速由12~12.5 kg/min降低至10~10.5 kg/min,电渣锭氧含量控制在30×10^(-6)以下等措施,合金热塑性得到明显改善。
The Hastelloy G3 corrosion-resistant alloy 6t electroslag ingot produced by the 25t EAF-LF-VOD casting electrode electroslag remelting process was forged into a round rod with a diameter ofΦ350mm,and a large number of cracks appeared on the surface.In order to study the causes for the cracks,samples were taken at different positions of the forging rod to analyze the gas and inclusion levels.The crack defects were observed under scanning electron microscopy and the composition of the defects was analyzed.The analysis results showed that:The reason for the cracks is that the rapid melting rate of electroslag remelting process leads to high oxygen content in the electroslag ingot,and a large number of brittle inclusions accumulate and precipitate at the grain boundary,resulting in poor thermoplastic properties of the material,which leads to cracks during the forging process.By using the(%)CaF_(2):Al_(2)O_(3):CaO=75:15:10 slag system instead of the original(%)CaF_(2):Al_(2)O_(3)=70:30 slag system,improving the electroslag melting rate from 12 to 12.5 kg/min to 10 to 10.5 kg/min,and controlling the oxygen content of the electroslag ingot below 30×10^(-6),the thermoplastic properties of the alloy have been significantly improved.
作者
崔利民
栾吉喆
陈保梁
李本朋
Cui Limin;Luan Jizhe;Chen Baoliang;Li Benpeng(Avic Shangda Superalloys Company Limited,Xingtai 054800,Hebei,China;Hebei Provincial Key Laboratory of Corrosion Resistant Alloy Materials,Xingtai 054800,Hebei,China;Key Laboratory of Hebei Province on High Temperature Alloy Regeneration Technology,Xingtai 054800,Hebei,China)
出处
《特钢技术》
CAS
2023年第4期16-20,共5页
Special Steel Technology
基金
邢台市重点研发计划—高新技术领域专项(编号:2022zz015)。
关键词
耐蚀合金
电渣锭
夹杂物
锻造裂纹
氧含量
corrosion resistant alloy
electroslag ingot
inclusions
forging crack
oxygen content
