THERMAL OXIDATION OF Ti6Al4V ALLOY WITH ENHANCED WEAR AND CORROSION RESISTANCE FOR OIL AND GAS APPLICATION: EFFECT OF TEMPERATURE

2015 ◽  
Vol 22 (03) ◽  
pp. 1550033 ◽  
Author(s):  
NAIMING LIN ◽  
PENG ZHOU ◽  
YATING WANG ◽  
JIAOJUAN ZOU ◽  
YONG MA ◽  
...  

Thermal oxidation (TO) treatments were performed at 873 K, 898 K, 923 K, 948 K, 973 K, 998 K and 1023 K for 10 h in air to improve the wear and corrosion resistance of Ti 6 Al 4 V alloy. The effect of TO temperature on microstructural characterizations and surface properties of the obtained TO layers were investigated. The results showed that TO layers with various thickness values were formed on Ti 6 Al 4 V alloy under different temperatures. The thickness of the TO layers increased with the increasing of TO temperature. TO layer that was obtained at 973 K suggested the highest surface hardness and the best wear resistance. TO layer that was realized at 948 K exhibited superior corrosion resistance to other TO layers. TO treatment could be considered as an effective method for preventing wear and corrosion of Ti 6 Al 4 V alloy.

Author(s):  
L.-M. Berger ◽  
P. Vuoristo ◽  
T. Mäntylä ◽  
W. Kunert ◽  
W. Lengauer ◽  
...  

Abstract WC-Co-Cr represents an important composition for hardmetal-like coatings which is appHed when simuhaneous wear and corrosion resistance is required. In this paper five commercially available spray powders obtained by various production techniques (sintered and crushed as well as agglomerated and plasma-densified) of the composition WC-10%Co- 4%Cr have been thoroughly characterized and were sprayed by DCS, HVOF (CDS process) and APS. The microstructures of the coatings were characterized and their wear behaviour was investigated by means of an abrasion wear test. For the best of these powders the wear resistance was nearly equal for the DGS and HVOF coatings. Other powders show significant differences with respect to their processabilities in these spray processes. APS coatings from all powders, obtained with an Ar/H2 plasma showed inferior microstructures and significant lower wear resistance. The spray powder compositions, grain sizes and structures were found to determine the processability of the powders and the microstructure and properties of the coatings. COMPOSITE MATERIALS of the type hard phase - metallic binder with WC and CoCr as constituents are widely used for the preparation of hardmetal-like coatings. The chromium addition to the metallic binder is thought to improve its corrosion resistance in comparison with pure WC-Co. This has led to many applications of WC-CoCr coatings where simultaneous wear and corrosion resistance is required. Despite of its significant practical importance only a limited number of publications is devoted to detailed questions of structure and properties of WC-CoCr coatings (1-3). In some comparative studies such coatings have been investigated together with WC-Co and Cr3C2-NiCr coatings (4-8). However, systematic investigations of spray powder compositions and morphologies as well as investigations of the influence of different thermal spray processes on coating structures and properties which have repeatedly been provided for WC-Co (for example (9, 10)) are missing for WC-CoCr. In this paper a short survey of literature on the phase relationships in the WC-CoCr system and the effect of chromium additions on the properties of sintered parts and thermally sprayed coatings compared to WC-Co is given. In the experimental part a systematic study of the influence of the preparation process on composition and morphology of commercially available WC-10%Co-4%Cr spray powders was provided. These powders have been sprayed by DGS, HVOF and APS and the microstructure and basic properties of the coatings have been studied.


Author(s):  
I. Kretschmer ◽  
P. Heimgartner ◽  
R. Polak ◽  
P.A. Kammer

Abstract Fusible Ni-B-Si alloys with a variety of alloy additions (Cr, Mo, Cu etc.) have been in service for many years as fused coatings with moderate corrosion resistance. Both gas- and water-atomised powders have been used with the spray and fuse and with the plasma transferred arc process to produce coatings. As the severity of corrosive industrial environments has increased, for example in waste burning boilers, existing alloys have not provided the desired service performance. This study was undertaken to develop a new family of alloys with improved corrosion resistance without sacrificing usability, wear resistance or cost effectiveness. A range of compositions was prepared and evaluated for deposition characteristic, microstructure, hardness, wear resistance and corrosion resistance in various media. The resulting alloy has an exceptional combination of wear and corrosion resistance in comparison to conventional alloys, when tested under comparable conditions.


Entropy ◽  
2018 ◽  
Vol 20 (12) ◽  
pp. 915 ◽  
Author(s):  
Kaijin Huang ◽  
Lin Chen ◽  
Xin Lin ◽  
Haisong Huang ◽  
Shihao Tang ◽  
...  

In order to improve the wear and corrosion resistance of an AZ91D magnesium alloy substrate, an Al0.5CoCrCuFeNi high-entropy alloy coating was successfully prepared on an AZ91D magnesium alloy surface by laser cladding using mixed elemental powders. Optical microscopy (OM), scanning electron microscopy (SEM), and X-ray diffraction were used to characterize the microstructure of the coating. The wear resistance and corrosion resistance of the coating were evaluated by dry sliding wear and potentiodynamic polarization curve test methods, respectively. The results show that the coating was composed of a simple FCC solid solution phase with a microhardness about 3.7 times higher than that of the AZ91D matrix and even higher than that of the same high-entropy alloy prepared by an arc melting method. The coating had better wear resistance than the AZ91D matrix, and the wear rate was about 2.5 times lower than that of the AZ91D matrix. Moreover, the main wear mechanisms of the coating and the AZ91D matrix were different. The former was abrasive wear and the latter was adhesive wear. The corrosion resistance of the coating was also better than that of the AZ91D matrix because the corrosion potential of the former was more positive and the corrosion current was smaller.


2016 ◽  
Vol 853 ◽  
pp. 441-445
Author(s):  
Cheng Zhou Chen ◽  
Wei Ze Wang ◽  
Kai Di Cheng

The vessel containing sulfur particles has been found failing due to the effect of corrosion and erosion by the sulfur particles. Several coatings, including zinc-aluminum coating, wear-resistance painting and two kinds of polymer, have been provided to resist the negative influence of sulfur in the present study. The wear and corrosion resistance of the selected coatings has been measured to study the performance difference. Impact test has also been done to investigate the bonding condition of coatings under the impact or bending load. The microstructure of coatings before and after wear test is observed by the Optical Microscope (OM) and Scanning Electron Microscope (SEM). The experiment results reveal that one of the polymer coatings shows the best performance in the corrosion resistance, another polymer coating’s wear resistance is better than others. The coatings are bonded well with the substrate except the zinc-aluminum coating. The performance of painting is ordinary in this investigation.


2011 ◽  
Vol 183 ◽  
pp. 149-154
Author(s):  
Waldemar Serbiński ◽  
Tadeusz Wierzchoń

Aluminium alloys are the materials of choice when high-strenght-to-weight rations are required in structural components, and used widely in the automotive and aerospace industries. As an example, the use of an aluminium components in the automobile industry has greatly increased due to weight savings and resultant fuel economy improvements. There are many methods of surface consolidation of an aluminium alloys. This work presents the hybrid creation method of the newly layers type (Mn-P) on the AlSi13Mg1CuNi alloy, its microstructure, hardness, chemical and phase compositions as well as wear and corrosion resistance. Growth the wear resistance of an aluminium alloy coated with the layer type (Mn-P) is visable. The corrosion characteristics of these layers are also considered.


2011 ◽  
Vol 312-315 ◽  
pp. 994-999 ◽  
Author(s):  
Riza Karadas ◽  
Ozgur Celik ◽  
Huseyin Cimenoglu

Nitriding is as an effective technique applied for many years to improve the surface hardness and wear resistance of low carbon and tool steels [1]. In the case of stainless steels, increase of surface hardness and wear resistance accompany by a drop in corrosion resistance due to the precipitation of CrN. In this respect, many attempts have been made to modify the surfaces of austenitic stainless steels to increase their surface hardness and wear resistance without scarifying the corrosion resistance [2-6]. It is finally concluded that, nitriding at temperatures lower than conventional nitriding process (which is generally about 550°C) has potentiality to produce a nitrogen expanded austenite (also known as S-phase), on the surface without formation of CrN. Due to the superb properties of the S-phase, the low temperature nitrided austenitic stainless steels exhibit very high surface hardness, a good wear resistance, and more importantly, an excellent corrosion resistance. Recently some attempts have been made to apply low temperature nitriding to martensitic stainless steels, which are widely used in the industries of medicine, food, mold and other civil areas [7-9]. In these works, where nitriding has been conducted by plasma processes, superior surface hardness, along with excellent wear and corrosion resistances have been reported for AISI 410 and AISI 420 grade martensitic stainless steels. This work focuses on low temperature gas nitriding of AISI 420 grade martensitic stainless steel in a fluidized bed reactor. In this respect the microstructures, phase compositions, hardness, wear and corrosion behaviours of the original and nitrided martensitic stainless steels have been compared.


Alloy Digest ◽  
1999 ◽  
Vol 48 (1) ◽  

Abstract Crucible CPM 420V is a unique tool steel made by the Crucible particle metallurgy (CPM) process. The alloy is designed from a martensitic stainless steel based analysis with added carbon and vanadium for exceptionally good wear resistance. CPM 420V offers significant improvements over CPM 440V in both wear and corrosion resistance. The exceptional wear resistance and good corrosion resistance of CPM 420V make it an excellent candidate to replace 440C and other corrosion- and wear-resistant materials, particularly where increased wear resistance is a primary concern. This datasheet provides information on composition, physical properties, hardness, and elasticity as well as fracture toughness. It also includes information on corrosion and wear resistance as well as heat treating and machining. Filing Code: SS-736. Producer or source: Crucible Service Centers.


Coatings ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 809 ◽  
Author(s):  
Dariusz Bartkowski ◽  
Aneta Bartkowska ◽  
Adam Piasecki ◽  
Peter Jurči

The paper presents the study results of a laser cladding process of C45 steel using powder mixtures. The aim of this study was to investigate the microstructure, X-ray diffraction (XRD), chemical composition (EDS), microhardness, corrosion resistance and wear resistance of the newly obtained coatings. Modified coatings were prepared using laser cladding technology. A 1 kW continuous wave Yb:YAG disk laser with a powder feeding system was applied. Two different powder mixtures as well as various laser beam parameters were used. The first powder mixture contained Fe–B, and the second mixture was Fe–B–B4C–Si. Two values of laser beam power (600 and 800 W) and three values of scanning speed (600, 800, and 1000 mm/min) were applied during the studies. As a result of the influence of the laser beam, the zones enriched with modifying elements were obtained. Based on the results of XRD, the presence of phases derived from borides and carbides was found. In all cases analyzed, EDS studies showed that there is an increased content of boron in the dendritic areas, while there is an increased silicon content in interdendritic spaces. The addition of B4C and Si improved properties such as microhardness as well as wear and corrosion resistance. The microhardness of the coating increased from approx. 400 HV to approx. 1100 HV depending on the laser parameters used. The best corrosion resistance was obtained for the Fe–B–B4C–Si coating produced using the highest laser beam scanning speed. An improvement in wear resistance can be seen after wear tests, where the weight loss decreased from about 0.08 g to about 0.05 g.


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