Scholarlink

We investigated the phase transformations during butt-welding of supermartensitic steel plates with help of Neutron Bragg-Edge Imaging (NBEI). Gas tungsten arc welding (GTAW) was used with a motorized torch allowing for automated weldments. The austenitization in the heat affected zone (HAZ) could be clearly visualized at λ = 3.95 Å, a wavelength smaller than the Bragg edge wavelengths of both austenite and martensite phases. The re-transformation into the martensitic phase during cooling was clearly detected. However, we observed an unexpected additional change in transmission at λ = 4.4 Å, a wavelength larger than the wavelengths of the Bragg edges of both the martensitic and austenitic phases. We attribute this change to the temperature dependence of coherent scattering at a crystal lattice. The observed two-dimensional attenuation map corresponds well with a temperature distribution modelling by software macros in ANSYS. Here, the absolute temperature values could be achieved by calibrating the modelled attenuation with help of a thermocouple placed at the steel plate. This allows in return for a direct two-dimensional temperature reading based on the relation between the neutron attenuation caused by the inelastic neutron scattering and the sample temperature. The method was extended further to 3D mapping of temperature distribution in bulky steel samples.

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Crystallographic Phase Transformations and Corresponding Temperature Distributions During GTAW of Supermartensitic Stainless Steel Visualized by Neutron Bragg-Edge Imaging

  • 会议论文

  • 出版模式：

    开放获取

  • 发表日期：

    2026年

查看全文
  • Axel Griesche,
  • Tobias Mente,
  • Alessandro Tengattini,
  • Stefano Dal Pont,
  • Nikolay Kardjilov

摘要

We investigated the phase transformations during butt-welding of supermartensitic steel plates with help of Neutron Bragg-Edge Imaging (NBEI). Gas tungsten arc welding (GTAW) was used with a motorized torch allowing for automated weldments. The austenitization in the heat affected zone (HAZ) could be clearly visualized at λ = 3.95 Å, a wavelength smaller than the Bragg edge wavelengths of both austenite and martensite phases. The re-transformation into the martensitic phase during cooling was clearly detected. However, we observed an unexpected additional change in transmission at λ = 4.4 Å, a wavelength larger than the wavelengths of the Bragg edges of both the martensitic and austenitic phases. We attribute this change to the temperature dependence of coherent scattering at a crystal lattice. The observed two-dimensional attenuation map corresponds well with a temperature distribution modelling by software macros in ANSYS. Here, the absolute temperature values could be achieved by calibrating the modelled attenuation with help of a thermocouple placed at the steel plate. This allows in return for a direct two-dimensional temperature reading based on the relation between the neutron attenuation caused by the inelastic neutron scattering and the sample temperature. The method was extended further to 3D mapping of temperature distribution in bulky steel samples.