Induction cladding layer of cladding wear and corrosion properties of the preparation and organization

Title: Induction cladding layer of cladding wear and corrosion properties of the preparation and organization
　　Author: Zhong Na
　　Degree awarded: China University of Petroleum
　　Keywords: protective agent;; cold-coating;; Induction cladding;; earth;; Al;; electrochemical corrosion;; erosion
　　Summary:
　　Sucker rod oil extraction operations in order to solve the coupling problem of corrosion and wear, extending its life, improve surface hardness and wear and corrosion resistance, this choice of cladding induced by cold-coating process to be rare earth magnets addressed. The process for the surface alloying element present in burning, easy flowing cladding layer, forming the surface problem of the poor, the need to develop suitable self-protective agent. According to self-protection principles and B2O3-SiO_2 phase diagram, with SiO_2, Al_2O_3, TiO_2, H_2BO_3 boron aluminum silicate as the main skeleton of Al powder, rare earth, lanthanum oxide, CaF2 as additives, according to the screen out to the surface morphology of W ( SiO_2) / (W (H_2BO_3) + W (SiO_2)) ≈ 90%, W (Al_2O_3) + W (SiO_2) + W (TiO_2) ≥ 60%, 5% Al powder-based self-protection formulations, in the basic formula and then were added 5% CaF2 and 6% La2O3, its cladding layer formed of the optimum. Protection under the three agents formed macro-Ni60 clad layer morphology, microstructure, microhardness, XRD, SEM analysis, the study found: the Al powder + rare-earth oxide additives when the protective agent, not only solved general induction cladding cladding easy flowing, forming problem of the poor, but also to make cladding alloy elements B, Ni oxidation reduction burning, and the cladding layer of tissue density, porosity is small, the best overall performance. In order to best protect the agent under the protection of the Ni60A powder as matrix to study the different levels of Cr_3C_2-NiCr powder of Ni-based cladding layer of organization performance. Through the cladding layer morphology, XRD, microhardness, erosion properties, corrosion resistance found: numerous experiments in metallurgy combined with the cladding layer has a line in there to ensure a high bonding strength, melting http://www.chinamagnets.biz/ covered by a thick layer of tissue into a small dendrite daisy-like; join NiCr-Cr_3C_2 after the phase structure of the cladding layer changes in the Ni-based solid solution, Cr_3C_2, Cr_7C_3, CrB and Ni_3B phase adds M23 (C, B) 6 strengthening phase; when Cr_3C_2-NiCr content of 35%, the cladding layer forming the surface of the best, most uniform dispersion microstructure, microhardness values ​​of the average highest erosion resistance performance of the best; and also come to Cr3C2-NiCr added to make way by the corrosion of the cladding layer into a fully localized pitting corrosion, when the Cr3C2-NiCr content of 45%, the pitting effect is obvious.
　　Degree Year: 2010