School of Materials Science and Engineering, Changwon National University, Changwon 51140, Korea.
J Nanosci Nanotechnol. 2020 Nov 1;20(11):6904-6911. doi: 10.1166/jnn.2020.18813.
Shot peening for nanocrystallization of the surface region is a good way of improving corrosion-, fatigue-, and wear-resistance, etc. of metallic parts (Lu, K., 2014. Making strong nanomaterials ductile with gradients. (6203), pp.1455-1456). The technique has been widely used for various materials as a method of surface modification. SUS316 has excellent corrosion and oxidation resistance with good formability However, its application is limited by the low mechanical strength and hardness. S32750 (duplex stainless steel) is one of most used tubing materials for oil/gas delivery systems in a corrosive environment under high pressure (Nilsson, J.O., 1992. Super duplex stainless steels. (8), pp.685-700). Thus, improving corrosion resistance is a key for the wider application and better maintenance of S32750. In our study, the alloy S32750 was heat-treated at 1070°C to obtain a precipitation-free microstructure ( and dual-phase structure). It was then ultrasonic shot peened and microstructures were analyzed for: (1) surface nanocrystallization, (2) effect of the treatment processing parameters, and (3) the determination of microstructural evolution and the effect of the shot peening process.
喷丸处理是一种通过表面纳米晶化来提高金属零件耐腐蚀性、疲劳性和耐磨性等性能的有效方法（Lu, K., 2014. Making strong nanomaterials ductile with gradients. (6203), pp.1455-1456）。该技术已广泛应用于各种材料的表面改性。SUS316 具有优异的耐腐蚀性和抗氧化性，且具有良好的成形性。然而，其应用受到机械强度和硬度低的限制。S32750（双相不锈钢）是在高压腐蚀性环境下输送油气系统中使用最广泛的管材之一（Nilsson, J.O., 1992. Super duplex stainless steels. (8), pp.685-700）。因此，提高耐腐蚀性是扩大 S32750 应用范围和更好维护的关键。在我们的研究中，将合金 S32750 在 1070°C 下进行热处理，以获得无析出相的微观结构（和双相结构）。然后对其进行超声喷丸处理，并对微观结构进行分析：（1）表面纳米晶化，（2）处理工艺参数的影响，以及（3）微观结构演变和喷丸处理过程的影响的确定。
