表面技术2017，Vol.46Issue(1)：218-223,6.DOI:10.16490/j.cnki.issn.1001-3660.2017.01.035
45#钢Cr-N包埋共渗涂层的组织特征及形成机理
Microstructure Characteristics and Formation Mechanism of Co-Deposition Coating on Plain 45# Carbon Steel via Simultaneous Chro-mising and Nitriding by Pack Cementation Process
鲁显京 1向志东1
作者信息
- 1. 武汉科技大学 省部共建耐火材料与冶金国家重点实验室 材料与冶金学院,武汉 430081
- 折叠
摘要
Abstract
The work aims to study the feasibility of increasing the corrosion resistance of 45# plain carbon steel by forming a Cr2N coating layer. Cr2N co-deposition coatings at different stages were obtained by holding the temperature for different dura-tions at 1100℃. The microstructure and formation mechanism of the coatings were studied by using SEM, EDS and XRD. Corrosion resistance of the coatings was assessed by virtue of electrochemical anodic polarisation curves. Optimal coating was obtained for 45# steel Cr2N pack infiltration when holding time was 4 h. The coating consisted of a top Cr2N layer (≈15μm), a deposited layer of Cr (≈10μm) and diffusion layer of Cr (≈15μm). The top Cr2N layer had strong (002) predominant crys-tal orientation. Carbide phases of Fe-Cr alloy and Chromium (Cr7C3, Cr3C2) were found in the deposited layer of Cr. In the si-mulated corrosive liquid of fuel cell, the self-corrosion potentials of 45# steel, 45# coating sample and 304L stainless steel were?0.521 V,?0.448 V and?0.299 V respectively, and self-corrosion current 230.63μA·cm-2, 10.89μA·cm-2 and 5.26μA·cm-2 respectively. Coating samples showed secondary passivation and the corrosion current was 1.43μA·cm-2 when corrosion po-tential exceeded 0.3 V. Compared with the uncoated steel, corrosion resistance of the Cr2N coated 45# steel increases signifi-cantly, and is superior to that of 304SS when the corrosion potential is more than 0.3 V.关键词
Cr2N涂层/包渗法/45#钢/耐蚀性/组织特征Key words
Cr2N layer/pack cementation/45 carbon steel/corrosion resistance/microstructure分类
矿业与冶金引用本文复制引用
鲁显京,向志东..45#钢Cr-N包埋共渗涂层的组织特征及形成机理[J].表面技术,2017,46(1):218-223,6.
