• CN:11-2187/TH
  • ISSN:0577-6686

机械工程学报 ›› 2015, Vol. 51 ›› Issue (10): 41-47.doi: 10.3901/JME.2015.10.041

• 材料科学与工程 • 上一篇    下一篇

不同冷却条件下激光焊接接头性能研究

卢庆华1, 郭崇1, 郭屹2, 何晓峰1, 彭必荣1   

  1. 1.上海工程技术大学材料工程学院 上海 201620;
    2.太原科技大学材料科学与工程学院 太原 030024
  • 出版日期:2015-05-15 发布日期:2015-05-15
  • 基金资助:
    国家自然科学基金(51305253)、上海高校一流学科建设计划(YLJX12-2)和上海工程技术大学研究生科研创新专项(13KY502)资助项目

Element Free Galerkin Method Coupled Flow Function for Plane Strain Strip Rolling Process

LU Qinghua1, GUO Chong1, GUO Yi2, HE Xiaofeng1, PENG Birong1   

  1. 1. School of Materials Engineering, Shanghai University of Engineering Science, Shanghai 201620;
    2. School of Materials Science and Engineering, Taiyuan University of Science and Technology, Taiyuan 030024
  • Online:2015-05-15 Published:2015-05-15

摘要: 分别利用焊后空冷和随焊水冷两种随焊冷却方式对2 mm厚低碳钢板进行光纤激光焊接。选择不同激光功率、焊接速度和离焦量进行试验。分析焊后空冷条件下和随焊水冷条件下两种焊接接头成形、金相组织和显微硬度。研究结果表明,随焊水冷条件下的焊缝宽度和热影响区宽度分别小于焊后空冷条件下的焊缝宽度和热影响区宽度;在热输入相等和正离焦的前提下,熔宽随着离焦量的减小而增大。两种冷却条件下的焊缝组织为板条状先共析铁素体和珠光体。随焊水冷条件下热影响区晶粒尺寸较焊后空冷下的晶粒有明显细化。空冷条件下焊缝中柱状晶的生长方向与焊缝中心线成70°~80°,而随焊水冷条件下的柱状晶生长方向几乎与焊缝中心线垂直。焊后空冷和随焊水冷的焊缝区域平均硬度分别为316.7 HV0.2和331.5 HV0.2,均高于母材硬度平均值181.8 HV0.2;同时,随焊水冷条件下焊缝硬度稍高于焊后空冷条件下的焊缝硬度。

关键词: 光纤激光焊接, 空冷, 水冷, 组织分析

Abstract: 2 mm thick low carbon steels are welded with butt joints under air cooling(AC)and water cooling(WC)conditions respectively. Different parameters of laser power, welding speed and off-focus length are selected. The joint formation, microstructure and microhardness of welded joints are analyzed after welding. The results show that the width of weld metal(WM)and heat affected zone (HAZ) in WC are less than that in AC. Weld width increases with the decreasing of focal distance under the same condition of heat input and positive defocus. Microstructure of WM is composed of lath proeutectoid ferrite and pearlite. The grain size of HAZ is refined obviously in water cooling compared with that in air cooling method. The angle between the growth direction of columnar crystal and the center line of weld is about 70°-80°under the air cooling condition. But under water cooling condition, the growth direction is almost perpendicular to the center line. The average microhardness of weld in AC and WC are 316.7 HV0.2 and 331.5 HV0.2, which are both higher than 181.8 HV0.2 of the base metal. Meanwhile, the weld hardness under WC is slightly higher than that under AC.

Key words: air cooling, fiber laser welding, microstructure analysis, water cooling

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