Yoo Young-Ran, Choi Seung-Heon, Kim Young-Sik
Materials Research Centre for Energy and Clean Technology, Andong National University, 1375 Gyeongdong-ro, Andong 36729, Republic of Korea.
School of Materials Science and Engineering, Andong National University, 1375 Gyeongdong-ro, Andong 36729, Republic of Korea.
Materials (Basel). 2023 Jan 13;16(2):804. doi: 10.3390/ma16020804.
Dry canisters used in nuclear power plants can be subject to localized corrosion, including stress corrosion cracking. External and residual tensile stress can facilitate the occurrence of stress corrosion cracking. Residual stress can arise from welding and plastic deformation. Mitigation methods of residual stress depend upon the energy used and include laser peening, ultrasonic peening, ultrasonic nanocrystal surface modification, shot peening, or water jet peening. Among these, laser peening technology irradiates a continuous laser beam on the surface of metals and alloys at short intervals to add compressive residual stress as a shock wave is caused. This research studied the effect of laser peening with/without a thin aluminum layer on the corrosion properties of welded 304L stainless steel. The intergranular corrosion rate of the laser-peened specimen was a little faster than the rate of the non-peened specimen. However, laser peening enhanced the polarization properties of the cross-section of 304L stainless steel, while the properties of the surface were reduced by laser peening. This behavior was discussed on the basis of the microstructure and residual stress.
核电站中使用的干式罐可能会遭受局部腐蚀，包括应力腐蚀开裂。外部和残余拉应力会促使应力腐蚀开裂的发生。残余应力可能源于焊接和塑性变形。残余应力的缓解方法取决于所使用的能量，包括激光喷丸、超声喷丸、超声纳米晶表面改性、喷丸或水射流喷丸。其中，激光喷丸技术以短时间间隔在金属和合金表面照射连续激光束，通过产生冲击波来添加压缩残余应力。本研究探讨了有无薄铝层的激光喷丸对焊接304L不锈钢腐蚀性能的影响。激光喷丸试样的晶间腐蚀速率比未喷丸试样的速率略快。然而，激光喷丸增强了304L不锈钢横截面的极化性能，而其表面性能则因激光喷丸而降低。基于微观结构和残余应力对这种行为进行了讨论。
