Abstract：17-4PH (Precipitation Hardening) stainless steel, as a common material for overflow components such as hydrofoils and turbines, is seriously damaged by cavitation, which causes many safety problems. There are limitations in the traditional process of preparing irregular and complex structural components. In contrast, additive manufacturing technology is a very efficient way of processing such parts. 17-4PH stainless steel was prepared by selective laser melting (SLM). The influence of solution+aging treated (1 040 ℃/1 h+480 ℃/4 h) and ion nitriding on the microstructure and cavitation properties of 17-4PH stainless steel prepared by SLM was studied. The results show that due to the characteristics of rapid cooling and directional solidification of SLM, a large amount of residual austenite is retained in the deposited state, including the columnar crystal and cellular structure in the molten pool along the construction direction. After solution+aging treatment, the original molten pool boundary disappears, the structure is equiaxed crystal, and the strengthening phase precipitates. After ion nitriding treated, a hard layer of nitride of about 20 μm is formed on the surface of the sample. After ion nitriding treatment, the relative content of residual austenite in the sample decreased from 13.1% in the deposited state to 7.5%. In addition, nitrogen infiltration into the matrix material also causes lattice distortion, resulting in a significant shift in the diffraction peak. When cavitation damage occurs, crack initiation and propagation take precedence at the overlap of the melting channel. After solution + aging treated, the cavitation quality is reduced from 7.4 mg as deposit to 5.9 mg after 8 h cavitation damage due to elimination of the melting pool and the boundary of the melting channel and precipitation of the strengthened phase. After nitriding treatment, a hard nitride layer can be formed on the surface of the sample to further improve the cavitation resistance, cavitation damage causes minimal damage to the surface of the sample, resulting in minimal material detachment and a loss of only 5.5 mg of cavitation mass.
[1] 杨钢,吴江枫,陈新建,等. 热处理工艺对GTD-450叶片钢力学性能的影响[J]. 钢铁,2010,45(5):61.(YANG G,WU J F,CHEN X J,et al. Effect of heat treatment on mechanical properties of GTD-450 blade steel[J]. Iron and Steel,2010,45(5):61.) [2] 黄根良. 17-4PH沉淀硬化不锈钢的组织和性能研究[J]. 钢铁,1998,33(4):46.(HUANG G L. Study on the structure and performance of 17-4PH stainless steel[J]. Iron and Steel,1998,33(4):46.) [3] 魏瑛康,刘瑶珊,王岩,等. 不锈钢表面激光熔覆强化层研究现状与展望[J]. 中国冶金,2022,32(11):6.(WEI Y K,LIU Y S,WANG Y,et al. Research status and prospect of laser cladding strengthening layer on stainless steel surface[J]. China Metallurgy,2022,32(11):6.) [4] 王岩,屈栋,魏瑛康,等. 17-4PH马氏体沉淀硬化不锈钢表面防护技术研究进展[J]. 中国冶金,2022,32(10):13.(WANG Y,QU D,WEI Y K,et al. Research progress on surface protection technology of 17-4PH martensite precipitation hardening stainless steel[J]. China Metallurgy,2022,32(10):13.) [5] BABU A,ARORA H S,SINGH H,et al. Microwave synthesized composite claddings with enhanced cavitation erosion resistance[J]. Wear,2019,422:242. [6] ADNYANA D. Corrosion fatigue of a low-pressure steam turbine blade[J]. Journal of Failure Analysis and Prevention,2018,18:162. [7] KONDO T,ANDO K. One-way-coupling simulation of cavitation accompanied by high-speed droplet impact[J]. Physics of Fluids,2016,28(3):033303. [8] NI W W,CASS M,BARTHOLME D. The jet fuel hydrodynamic cavitation bubble size with cavitation power and energy from Rayleigh-Plesset equation[J]. SAE International Journal of Aerospace,2015,8(2):195. [9] HE J,LIU X,LI B,et al. Cavitation erosion characteristics for different metal surface and influencing factors in water flowing system[J]. Applied Sciences,2022,12(12):5840. [10] JI X,SHAN Y,JI C,et al. Slurry erosion behavior of two Zr-based bulk metallic glasses[J]. Wear,2021,476:203684. [11] ZHANG L,LI Z,HU J,et al. Understanding the roles of deformation-induced martensite of 304 stainless steel in different stages of cavitation erosion[J]. Tribology International,2021,155:106752. [12] WANG L,MAO J,XUE C,et al. Cavitation-erosion behavior of laser cladded low-carbon cobalt-based alloys on 17-4PH stainless steel[J]. Optics and Laser Technology,2023,158:108761. [13] 王维夫,郑玉贵. 17-4PH钢激光固溶-时效强化及抗空蚀性能[J]. 材料热处理学报,2013,34(9):155.(WANG W F,ZHENG Y G. Microstructure and properties of 17-4PH steel by laser solid solution and aging treatment and its cavitation erosion resistance[J]. Transactions of Materials and Heat Treatment, 2013,34(9):155.) [14] ZHANG Q,WU L,ZOU H,et al. Correlation between microstructural characteristics and cavitation resistance of Stellite-6 coatings on 17-4PH stainless steel prepared with supersonic laser deposition and laser cladding[J]. Journal of Alloys and Compounds,2021,860:158417. [15] LASHGARI H,XUE Y,ONGGOWARSITO C,et al. Microstructure, tribological properties and corrosion behaviour of additively manufactured 17-4PH stainless steel: Effects of scanning pattern, build orientation, and single vs. double scan[J]. Materials Today Communications,2020,25:101535. [16] 王长军,刘雨,周健,等. 金属增材技术在钢铁领域的研究进展[J]. 中国冶金,2022,32(5):7.(WANG C J,LIU Y,ZHOU J,et al. Research progress of metal additive technology in iron and steel field[J]. China Metallurgy,2022,32(5):7.) [17] 黄永建,刘军会,杨进航,等. 增材制造模具的研究进展[J]. 中国冶金,2019,29(11):6.(HUANG Y J,LIU J H,YANG J H,et al. Research progress on additive manufactured molds[J]. China Metallurgy,2019,29(11):6.) [18] 刘世锋,魏钢,王岩,等. 增材制造17-4PH马氏体不锈钢研究进展[J]. 中国冶金,2022,32(6):15.(LIU S F,WEI G,WANG Y,et al. Research progress on additive manufacturing of 17-4PH martensitic stainless steels[J]. China Metallurgy,2022,32(6):15.) [19] PONNUSAMY P,SHARMA B,MASOOD S,et al. A study of tensile behavior of SLM processed 17-4PH stainless steel[J]. Materials Today: Proceedings,2021,45:4531. [20] 贾兴祺,李伟,许元涛,等. 基于增材制造的钢铁块体材料高通量实验方法[J]. 上海金属,2022,44(2):1.(JIA X Q,LI W,XU Y T,et al. High-throughput experimental method for steel bulk materials based on additive manufacturing[J]. Shanghai Metals,2022,44(2):1.) [21] 张亮亮,周阳,刘世锋,等. 模具钢增材制造及其性能的研究进展[J]. 中国冶金,2022,32(3):1.(ZHANG L L,ZHOU Y,LIU S F,et al. Research progress in additive manufacturing and properties of die steel[J]. China Metallurgy,2022,32(3):1.) [22] 刘世锋,宋玺,王岩,等. 金属粉床增材制造奥氏体不锈钢的研究进展[J]. 钢铁研究学报,2022,34(8):727.(LIU S F,SONG X,WANG Y,et al. Research progress of austenitic stainless steel made by metal additive manufacturing[J]. Journal of Iron and Steel Research,2022,34(8):727.) [23] 张忠和,陈炜,王志强,等. 高能束增材制造技术在风机叶轮上应用的研究[C]//第二届中国国际风机学术会议. 成都: 中国通用机械工业协会风机分会,沈阳鼓风机研究所和风机技术杂志社,2015.(ZHANG Z H,CHEN Y,WANG Z Q,et al. Application research of high energy beam additive manufacturing technology on fan impeller[C]//The 2nd China International Wind Turbine Conference. Chengdu: Fan Branch of China General Machinery Industry Association,Shenyang Air Blower Research Institute and Chinese Journal of Turbomachinery Chinese Journal of Turbomachinery,2015.) [24] CUESTA E,ALVAREZ B J,ZAPICO P,et al. Analysis of post-processing influence on the geometrical and dimensional accuracy of selective laser melting parts[J]. Rapid Prototyping Journal,2020,26(10):1713. [25] WANG D,CHI C T,WANG W Q,et al. The effects of fabrication atmosphere condition on the microstructural and mechanical properties of laser direct manufactured stainless steel 17-4PH[J]. Journal of Materials Science and Technology,2019,35(7):1315. [26] CHAO Q,THOMAS S,BIRBILIS N,et al. The effect of post-processing heat treatment on the microstructure, residual stress and mechanical properties of selective laser melted 316L stainless steel[J]. Materials Science and Engineering: A,2021,821:141611. [27] PASEBANI S,GHAYOOR M,BADWE S,et al. Effects of atomizing media and post processing on mechanical properties of 17-4PH stainless steel manufactured via selective laser melting[J]. Additive Manufacturing,2018,22:127. [28] MAHMOUDI M,ELWANY A,YADOLLAHI A,et al. Mechanical properties and microstructural characterization of selective laser melted 17-4PH stainless steel[J]. Rapid Prototyping Journal,2017,23(2):1. [29] BENARJI K,RAVI KUMAR Y,JINOOP A,et al. Effect of heat-treatment on the microstructure, mechanical properties and corrosion behaviour of SS316 structures built by laser directed energy deposition based additive manufacturing[J]. Metals and Materials International,2021,27:488. [30] GORSSE S,HUTCHINSON C,GOUNé M,et al. Additive manufacturing of metals: a brief review of the characteristic microstructures and properties of steels, Ti-6Al-4V and high-entropy alloys[J]. Science and Technology of advanced Materials,2017,18(1):584. [31] 欧阳鑫,胡昕明,王储,等. 模拟焊后热处理次数对Q370R钢板组织和性能的影响[J]. 上海金属,2021,43(4):51.(OU Y X,HU X M,WANG C,et al. Effect of simulated post welding heat treament times on microstructure and properties of Q370R steel plate[J]. Shanghai Metals,2021,43(4):51.) [32] 周华茂,王晓虹,孙智. 17-4PH不锈钢离子渗氮工艺[J]. 金属热处理,2003(6):32.(ZHOU M H,WANG X H,SUN Z. Ion-nitriding for 17-4PH stainless steel[J]. Heat Treatment of Metals,2003(6): 32.) [33] 李明星,黄润波,王均,等. 氮化时间对17-4PH不锈钢显微组织和冲蚀性能的研究[J]. 四川大学学报(工程科学版),2013,45(s1):163.(LI M X,HUANG R B,WANG J,et al. Effects of time on microstructure and erosion corrosion behavior of liquid nitrided 17-4PH stainless steel[J]. Advanced Engineering Sciences,2013,45(s1):163.) [34] DONG H,ESFANDIARI M,LI X Y. On the microstructure and phase identification of plasma nitrided 17-4PH precipitation hardening stainless steel[J]. Surface and Coatings Technology,2008,202(13):2969. [35] KOCHMAN＇SKI P,NOWACKI J. Activated gas nitriding of 17-4PH stainless steel[J]. Surface and Coatings Technology,2006,200(22):6558. [36] 徐匡迪,高玉来,翟启杰. 低镍不锈钢生产中的若干冶金学问题[J]. 钢铁,2004,39(7):1.(XU K D,GAO Y L,ZHAI Q J. Metallurgy lssues on production of low nickel stainless steels[J]. Iron and Steel,2004,39(7):1.) [37] QIAO Y,CHEN J,ZHOU H,et al. Effect of solution treatment on cavitation erosion behavior of high-nitrogen austenitic stainless steel[J]. Wear, 2019,424:70. [38] 傅万堂,张东升. 奥氏体铬锰氮不锈钢在气蚀过程中的组织变化[J]. 钢铁,1999,34(10):42.(FU W T,ZHANG D S. Microstructure changes during cavitation erosion for a CrMnN stainless steel with metastable austenite[J]. Iron and Steel,1999,34(10):42.) [39] SANG K,LI Y. Cavitation erosion of flame spray weld coating of nickel-base alloy powder[J]. Wear,1995,189(1):20.
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