Related Experiment Video
Updated: Feb 11, 2026

Ultrasonic Assessment of Myocardial Microstructure
Published on: January 14, 2014
Microstructural Evolution of Super304H Upon Ultrasonic Shot Peening and Subsequent Annealing
Kyeongae Nam1, Yinsheng He2, Keesam Shin1
1School of Nano and Advanced Materials Engineering, Changwon National University, Changwon 51140, Korea.
Abstract:
In this study we analyze the effect of shot peening on the microstructure and mechanical properties of Super304H, which is widely used for boiler tubes. Specimens were shot peened for 5, 10, and 15 minutes, and then heat treated at 600, 700, and 800 °C for 15 minutes. Vickers hardness was measured and the microstructure of cross sectional specimens was analyzed by scanning electron microscopy (SEM), electron backscattered diffraction (EBSD) and transmission electron microscopy (TEM). Heat treatment led to particle refinement on the upper layer of Super304H. In this region, nanograins, twins, and dislocations were generated to a depth of ~400 μm. The microstructure of the shot peened specimen did not change even after a heat treatment at 700 °C. However, rapid grain growth was observed after rapid annealing at 800 °C. Precipitation hardening occurred after heat treatment at 800 °C.
Related Concept Videos
The Evidence for Evolution
Convergent Evolution
Eukaryotic Evolution
Contrary to the endosymbiont theory, the eukaryote-first hypothesis proposes that the simpler prokaryotic and...
Synteny and Evolution
Around 80 million years ago, the human and mice lineages diverged from the common ancestor. During the course of evolution, the ancestral...
Gene Evolution - Fast or Slow?
Gene Evolution - Fast or Slow?
In contrast, regions which code...

