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过程工程学报 ›› 2023, Vol. 23 ›› Issue (2): 244-253.DOI: 10.12034/j.issn.1009-606X.222113

• 研究论文 • 上一篇    下一篇

15-7PH不锈钢电渣重熔过程夹杂物的行为

常立忠1, 项淼苗1, 徐涛2, 张龙飞1, 苏云龙1, 金涛1, 施晓芳1*
  

  1. 1. 安徽工业大学冶金工程学院,安徽 马鞍山 243002 2. 安徽富凯特材有限公司,安徽 绩溪 245300
  • 收稿日期:2022-03-31 修回日期:2022-04-19 出版日期:2023-02-28 发布日期:2023-03-01
  • 通讯作者: 施晓芳 shixiaofang602@163.com
  • 作者简介:常立忠,博士,教授,钢铁冶金专业,E-mail: clz1997@163.com;通讯联系人,施晓芳,副教授,从事不锈钢冶金及电渣重熔的研究, E-mail: shixiaofang602@163.com
  • 基金资助:
    电渣重熔过程增氧机理研究

Behavior of inclusions during electroslag process of 15-7PH stainless steel

Lizhong CHANG1,  Miaomiao XIANG1,  Tao XU2,  Longfei ZHANG1,  Yunlong SU1,  Tao JIN1,  Xiaofang SHI1*   

  1. 1. School of Metallurgy Engineering, Anhui University of Technology, Ma'anshan, Anhui 243002, China 2. Anhui Fukai Special Material Co., Ltd., Jixi, Anhui 245300, China
  • Received:2022-03-31 Revised:2022-04-19 Online:2023-02-28 Published:2023-03-01

摘要: 为了明晰15-7PH沉淀硬化不锈钢中夹杂物的行为,进一步提高其洁净度,采用超高功率电弧炉初炼→AOD (Argon Oxygen Decarburization)脱碳→LF (Ladle Furnace)精炼→模铸工艺制备了自耗电极,并用带压摆控制的气体保护电渣重熔炉进行重熔。采用HORIBA氧氮氢气体分析仪检测了电渣重熔前后氧、氮等含量的变化;ASPEX扫描电镜分析了夹杂物的尺寸、数目、化学成分、形貌等。结果表明,电渣重熔后15-7PH不锈钢中氧、氮含量有轻微的下降,但夹杂物的组成变化不大,主要由氮化物夹杂物(氮化铝+氮化钛)、氮化物-氧化物复合夹杂物、氧化物夹杂物、硫化物-氧/氮化物夹杂物组成,其中氮化物夹杂物尺寸最大、数量最多,明显高于其他夹杂物。电渣重熔对夹杂物的数量、尺寸有明显影响。重熔后夹杂数量大幅增加,氮化物尤为明显,但大颗粒夹杂物明显减少。氮化物夹杂物大量存在的主要原因在于钢中存在较高的Al, Ti, N等元素,而电渣过程由于熔渣吸附、部分夹杂物溶解,使大颗粒夹杂物减少,重熔过程的快速冷却抑制了夹杂物长大,最终结果是夹杂物尺寸更细小,但数量增加。

关键词: 洁净度, 15-7PH不锈钢, 电渣重熔, 氮化物, 夹杂物,

Abstract: In order to clarify the behavior of inclusions in 15-7PH stainless steel and further improve its cleanliness, the consumable electrodes were prepared by UHP electric arc furnace→AOD decarburization→LF refining→mold casting process, and remelted by gas shielded electroslag remelting furnace with voltage swing control. The changes of oxygen and nitrogen before and after electroslag remelting were analyzed by HORIBA gas analyzer. The size, number, chemical composition and morphology of inclusions were analyzed by ASPEX SEM. It was found that the content of oxygen and nitrogen in 15-7PH stainless steel decreased slightly after electroslag remelting, and there was little change in the composition of inclusions, which were mainly composed of nitride inclusions (AlN, TiN), nitride/oxide composite inclusions, oxide inclusions and sulfide-oxygen/nitride inclusions. Among them, nitride inclusions had the largest size and quantity, which were significantly higher than other inclusions, and were worthy of special attention. Electroslag remelting had an obvious effect on the number and size of inclusions. After remelting, the number of inclusions increased greatly, especially nitrides. However, large inclusions were significantly reduced. The main reason for the large amount of nitride inclusions was the high content of Al, Ti, N in the steel. During the electroslag process, due to the adsorption of slag and the dissolution of some nitrides, the large inclusions were reduced, and the rapid cooling in the remelting process inhibited the growth of inclusions which led to the small size but increased of the number of inclusions in the electroslag ingot.

Key words: Cleanliness, 15-7PH stainless steel, electroslag remelting, nitride, inclusion, oxygen