Microstructure and Performance of Aluminized Coatings Prepared by Pack-cementation Promoted by Surface Gradient Crystal Defects on 40Cr Steel

被引：0
|
作者：
Hu J. [1 ,2 ]
Wang D. [1 ]
Guo N. [3 ]
Yang X. [1 ]
Li H. [1 ]
Xu H. [2 ]
机构：
[1] College of Materials Science and Engineering, Chongqing University of Technology, Chongqing
[2] Chongqing Municipal Key Laboratory of Institutions of Higher Education for Mould Technology, Chongqing University of Technology, Chongqing
[3] School of Materials and Energy, Southwest University, Chongqing
来源：
Jixie Gongcheng Xuebao/Journal of Mechanical Engineering | 2023年 / 59卷 / 06期
关键词：
40Cr steel; Al-coating; gradient crystal defects; pack-cementation aluminizing; pre-torsion deformation;
D O I：
10.3901/JME.2023.06.114
中图分类号：
学科分类号：
摘要：
The pack-cementation aluminizing process is considered to be one of the most effective and economical methods to improve the corrosion resistance of steels. In this work, pre-torsion deformation combined with the pack-cementation aluminizing was conducted to prepared Al-coatings on the 40Cr steel. The steels were twisted prior to the aluminizing process, which can introduce high-density crystal defects into the steel surface, and increases the diffusion channels and thereby improving the diffusion rate of Al atoms during the aluminizing process. Microstructure of the samples before and after aluminizing was characterized systematically. The microhardness and corrosion resisting property were measured. The effects of pack-cementation temperatures (600, 650, 700 and 750 ℃) on the microstructure and properties of Al-coating were analyzed. The results show that the pre-torsion deformation introduces high-density crystal defects on the surface of 40Cr, which can improve the diffusion efficiency and increase the thickness of the infiltration layer. The higher the temperature, the thicker the infiltration layer, but the larger the grain size, the stronger the inhomogeneity of the structure and the lower the hardness. From 600 to 700 ℃, the corrosion resistance is gradually enhanced due to the thickening of the coating, but when the temperature reaches 750 ℃, more holes appear in the infiltrated layer, resulting in poor corrosion resistance. In contrast, the 700 ℃ sample is resistant to the best corrosion performance. © 2023 Editorial Office of Chinese Journal of Mechanical Engineering. All rights reserved.
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页码：114 / 122
页数：8
相关论文
共 21 条
  • [1] MORITA M, HASEGAWA K, MOTODA S., Effect of microstructure at coating layer on fatigue strength in hot-dip galvanized steel [J], ISIJ International, 60, 11, (2020)
  • [2] BAHREMANDD F, SHAHRABI T, RAMEZANZADEH B., Epoxy coating anti-corrosion properties enhancement via the steel surface treatment by nanostructured samarium oxide-poly-dopamine film[J], Journal of Hazardous Materials, 403, (2020)
  • [3] ZHANG Zuohua, SONG Guangyu, Thermal spraying for corrosion control of steel structure[J], Coating and Protection, 41, 6, pp. 42-46, (2020)
  • [4] XIANG Z D, DATTA P K., Pack cementation process for the formation of refractory metal modified aluminide coatings on nickel-base superalloys[J], Journal of Materials Science, 38, 18, pp. 3721-3728, (2003)
  • [5] XIE Xiangxu, WANG Yu, Research progress on aluminizing process of carbon steel[J], Heat Treatment Technology and Equipment, 31, 5, pp. 1-5, (2010)
  • [6] LU D, ZHANG Q, WANG W, Et al., Effect of cooling rate and the original matrix on the thermal diffusion alloyed intermetallic layer on magnesium alloys[J], Materials & Design, 120, pp. 75-82, (2017)
  • [7] XIANG Z D, ROSE S R, DATTA P K., Low-temperature formation and oxidation resistance of nickel aluminide/nickel hybrid coatings on alloy steels [J], Scripta Materialia, 59, 1, pp. 99-102, (2008)
  • [8] ZHAN Z L, YE-DONG H E, WANG D R，, Et al., Preparation of aluminide coatings at relatively low temperatures[J], Transactions of Nonferrous Metals Society of China, 16, 3, pp. 647-653, (2006)
  • [9] WANG Y Q, ZHANG Y, WILSON D A., Formation of aluminide coatings on ferritic–martensitic steels by a low-temperature pack cementation process[J], Surface & Coatings Technology, 204, 16-17, pp. 2737-2744, (2010)
  • [10] ZHANG Yuqing, Microstructures and properties of the gradient layer on 40Cr surface by thermal diffusion process, (2018)
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