With the rapid development of China's nuclear power industry, the design of some nuclear energy equipment has become more precise and complex. If traditional manufacturing techniques are used for production of these nuclear energy equipment, there are problems with long production cycles and multiple manufacturing processes. However, using additive manufacturing processes can achieve efficient production of equipment with complex and precise structures.

Stainless steel has excellent oxidation resistance, mechanical properties, and corrosion resistance, making it widely used in the field of nuclear power. Especially after the Fukushima accident, stainless steel (such as FeCrAl ferritic stainless steel, 316Ti, and 15-15Ti austenitic stainless steel) was selected as one of the main research and development directions for accident resistant fuel (ATF) materials for light water reactors. In addition, stainless steel materials have good welding performance, so the use of additive manufacturing technology can achieve good metallurgical bonding and forming. Introducing additive manufacturing technology into the nuclear power field will be beneficial for the development and application of accident resistant fuel materials.

The research team of China Nuclear Power Research and Design Institute published an article titled "Research Status of 316L Stainless Steel Powder Additive Manufacturing for Nuclear Power" in "Precision Forming Engineering", revealing the microstructure and properties of 316L stainless steel additive manufacturing formed parts before and after irradiation, as well as the indicator requirements of 316L stainless steel for nuclear power.

Additive manufacturing technology is an advanced manufacturing process that does not require molds and is nearly net formed. Stainless steel is a widely used structural material in the nuclear power industry. The implementation of additive manufacturing for stainless steel structural components will further promote the development of additive manufacturing technology and can also bring revolutionary changes to the nuclear industry. Taking 316L stainless steel used in nuclear power as an example, the research status of stainless steel powder additive manufacturing is systematically elaborated, including the current status of powder preparation process, additive manufacturing forming process, and the research status of microstructure and properties of formed parts.

At present, the preparation process of 316L stainless steel powder for additive manufacturing is mainly atomization method, and the physical and chemical properties of the powder are affected by the powder manufacturing process parameters. Among the laser powder bed melting additive manufacturing technology, electron beam selective melting technology, and plasma additive manufacturing technology, the application of laser powder bed melting additive manufacturing stainless steel is particularly widespread.

The microstructure and properties of 316L stainless steel produced by additive manufacturing exhibit anisotropy, but anisotropy can be eliminated through post-processing techniques in additive manufacturing. The most commonly used post-treatment technology in additive manufacturing is heat treatment. Compared with the forged 316L stainless steel, the mechanical properties and irradiation properties of 316L stainless steel made by additive treated by Hot isostatic pressing are better. At present, the additive manufacturing technology of nuclear stainless steel is still in its initial stage, and future attention should be paid to the forming mechanism of additive manufacturing and the neutron irradiation performance of formed materials.