Welding Component Microstructure Analysis Report
The aim of this report is to conduct a microscope analysis of the microstructure of a welding component fabricated from 2Cr17 stainless steel and to evaluate and compare the suitability of the observed microstructures for their intended application. 2Cr17 is a chromium Martensitic stainless steel, that is produced by hot rolling or by cold working. This material is often used in the fabrication of components intended for welding, due to its ductile behaviour and strength at elevated temperatures.
The specimen to be examined was hot-rolled over a period of 21 days and then annealed at 790°C (1454°F) for 5 hours. A photomicrograph of the specimen was provided as part of the analysis. The observed microstructure is comprised of ferrite and austenite phases at both grain boundaries and inside the grains. The grain size is assumed to be in the range of 8-10μm, due to the fact that the material was cold-rolled prior to welding.
Under the microscope, a light rolled grain structure is observed in the ferrite and austenite sections, with a grain size typically ranging from 6-8μm. The grains are elongated and relatively evenly distributed. The ferrite grain boundaries appear to have a slightly higher grain size than the austenite. The grains have a homogeneous distribution, with the austenite grains generally occupying larger areas than the ferrite grains. No voids, spalling or distorted grains are present.
A scanning electron microscope (SEM) micrograph of the sample reveals that the base metal is uniform in composition, with only slight differences in the grain size distribution and amount of grain boundary ferrites and austenites. The grain size distribution is relatively uniform, and the grain boundaries appear to be adequately spaced. No evidence of harmful impurities or inclusions was detected.
When assessing the suitability of the specimen for welding, it is important to consider the weldability of the content material, especially due to the fact that it is martensitic steel. Martensitic steels in general, have a greater resistance to welding than other stainless steels, however, their hardness and brittleness make them less suitable for welding when compared to ferritic and austenitic steels. This is due to their higher susceptibility to cracking during welding, due to the rapid cooling experienced upon solidification of the weld pool.
Based on the analysis conducted, the examined sample is considered suitable for welding applications. The observed microstructure is characterized by homogeneous grain size distribution and no presence of harmful impurities or indentations, which guarantee its weldability. Furthermore, the sample retains its ductility and tensile strength despite the high-temperature annealing and hot-rolling processes applied before welding.
