• CN:11-2187/TH
  • ISSN:0577-6686

机械工程学报 ›› 2015, Vol. 51 ›› Issue (24): 69-74.doi: 10.3901/JME.2015.24.069

• 材料科学与工程 • 上一篇    下一篇

扫码分享

B元素对FB2马氏体耐热钢热影响区组织和高温断裂韧度的影响

李克俭1,  蔡志鹏1,  李轶非1,  潘际銮1,  孙林根1,2   

  1. 1. 清华大学机械工程系  北京  100084;
    2. 上海电气电站设备有限公司汽轮机厂  上海  200240
  • 收稿日期:2014-12-11 修回日期:2015-06-14 出版日期:2015-12-15 发布日期:2015-12-15
  • 通讯作者: 蔡志鹏,男,1974年出生,博士,副研究员。主要研究方向为焊接冶金和焊接力学。 E-mail:czpdme@mail.tsinghua.edu.cn
  • 作者简介:李克俭,男,1989年出生,博士研究生。主要研究方向为耐热钢焊接冶金。 E-mail:lkj07@mails.tsinghua.edu.cn
  • 基金资助:
    上海市科学技术委员会资助项目(13DZ1101504)

Effect of Boron on the Microstructure and High Temperature Quasi-static Fracture Toughness of Heat Affected Zone in Heat-resistant Steel FB2

LI Kejian1,  CAI Zhipeng1,  LI Yifei1,  PAN Jiluan1,  SUN Lingen1,2   

  1. 1. Department of Mechanical Engineering, Tsinghua University, Beijing 100084;
    2. Turbine Plant, Shanghai Electric Power Generation Equipment Co., Ltd., Shanghai 200240
  • Received:2014-12-11 Revised:2015-06-14 Online:2015-12-15 Published:2015-12-15

摘要: 测试FB2马氏体耐热钢焊接热影响区(Heat affected zone, HAZ)在450 ℃下的准静态断裂韧度,结果表明HAZ的韧性与同条件下改良型9Cr-1Mo耐热钢母材的韧性持平。对HAZ进一步的金相、扫描电镜(Scanning electron microscopy, SEM)及透射电镜(Transmission electron microscopy, TEM)观察表明,FB2钢的HAZ中没有粗晶区,即在经历焊接热作用后晶粒并没有粗化;析出物均匀分布在晶内和晶界,并且晶界处的析出物尺寸要稍小于晶内析出物,这对于强化晶界提高韧性都是有利的。B元素在FB2的HAZ特殊的组织形成中发挥着重要作用,主要体现在通过占据析出物周围的空位来阻碍析出物长大,提高析出物的稳定性,进而影响焊接热过程中奥氏体的长大过程。

关键词: 耐热钢, 硼, 热影响区, 准静态断裂韧度

Abstract: The quasi-static fracture toughness of heat affected zone(HAZ) of martensite heat-resistant steel FB2 at 450 ℃ is tested, indicating that the toughness of HAZ is at the same level of modified 9Cr-1Mo parent metal’s. It is found that there is no coarse grain zone in the HAZ, and the second phases precipitate in prior austenite grain and boundary homogeneously. It is also found that the precipitates in the grain boundaries are smaller than those within the grains. The fine grains and small precipitates in grain boundaries make contribution to the high toughness of HAZ. Boron plays an important role in the formation of special structure of HAZ with occupying the vacancies around precipitates, in which way the stability of precipitates is enhanced and the growing of austenite is affected.

Key words: boron, heat affected zone(HAZ), heat-resistant steel, quasi-static fracture toughness