| About this Abstract |
| Meeting |
2024 AWS Professional Program
|
| Symposium
|
2024 AWS Professional Program
|
| Presentation Title |
Assessment of Weld Microstructure Through Sound Velocity Measurements for Power Plant Applications |
| Author(s) |
Obinna Onwuama, Jeong K Na, Aryan Aryan, Desmond Bourgeois, Wei Zhang |
| On-Site Speaker (Planned) |
Obinna Onwuama |
| Abstract Scope |
This study utilized an immersion-based micro-resolution ultrasonic velocity measurement technique (MUVT) to evaluate Grade 91 (9Cr-1Mo-V) steel welds. This process involved a 20 MHz focused ultrasonic beam with a spot size of 250 μm, a 6 μm laser vibrometer spot size for detection, and an automated 3-axis raster scanner to accurately collect ultrasonic velocity data for two Grade 91 steel welds fabricated through cold metal transfer (CMT) and flux-cored arc welding (FCAW) processes. By analyzing the data gathered from MUVT, Poisson's (ν) ratio and modulus of elasticity (E) were calculated, which are important mechanical properties for weldments. The correlation between mechanical properties and ultrasonic velocity was analyzed. The results indicated that longitudinal ultrasonic velocity could be used to identify the base metal (BM), heat-affected zone (HAZ), and weld metal (WM) areas, showing a good correlation with hardness. In particular, the distinctive V-shaped dip in velocity and hardness data crossing over the HAZ areas of both samples represents the change in the microstructure of creep strength-enhanced ferritic (CSEF) steel welds. Notably, the experimental data from the immersion-based MUVT showed high accuracy in small sections of the weld, exceeding the conventional contact ultrasonic testing (UT) method in detection spatial resolution. |
| Proceedings Inclusion? |
Undecided |