Corrosion Resistance of Vanadis 6 Steel after Conventional Heat Treatment and Sub-Zero Treatment in Cold Nitrogen Gas Followed by Tempering

2019 ◽  
Vol 395 ◽  
pp. 16-29
Author(s):  
Aneta Bartkowska ◽  
Peter Jurči
Keyword(s):  
Heat Treatment ◽  
Corrosion Resistance ◽  
Water Solution ◽  
Corrosion Current ◽  
Protective Oxide ◽  
Nitrogen Gas ◽  
Conventional Heat Treatment ◽  
Protective Films ◽  
The Matrix ◽  
Lower Corrosion Rate

The paper presents the results of study of corrosion resistance of Vanadis 6 steel after conventional heat treatment and sub-zero treatment at-140 °C for 17 h. It was found that sub-zero treatment leads generally to decrease in corrosion current, which is in turn reflected in lower corrosion rate of the material subjected to this kind of treatment. The corrosion potential of sub-zero treated specimens was more anodic, suggesting their more noble behavior in 3.5 % NaCl water solution. This behavior was ascribed to the presence of a huge number of small globular carbides in SZT specimens, which seemed to stabilize the protective oxide films on the surfaces. Tempering reduces the corrosion resistance of the steel since this treatment produces fine precipitates of alloyed carbides that deplete the matrix by chromium and thereby destabilizes the protective films on the steel surface.

Effects of Heat Treatment and Alloying of Spheroidal Graphite Cast Iron on Corrosion Resistance in Aqueous Environment

2004 ◽  
Vol 449-452 ◽  
pp. 533-536
Author(s):  
M. Aoyama ◽  
K. Tahashi ◽  
K. Matsuno
Keyword(s):  
Heat Treatment ◽  
Corrosion Resistance ◽  
Cast Iron ◽  
Current Density ◽  
Electrode Potential ◽  
Corrosion Current ◽  
Spheroidal Graphite ◽  
Spheroidal Graphite Cast Iron ◽  
Graphite Cast Iron ◽  
The Matrix

The present study examined the effects of heat treatment and the addition of Cu-Ni alloy on the corrosion resistance of the matrix of spheroidal graphite cast iron in aqueous environments. Test materials of white cast iron and carbon steel were used for comparison with spheroidal graphite cast iron. The alloy spheroidal graphite cast iron that added Cu and Ni was prepared. The spheroidal graphite cast iron was subjected to three kinds of heat treatment to adjust the matrix: annealing, oil quenching, and austemper heat treatment. In electrochemical tests, measurements of corrosion electrode potential and cathode and anode polarization were used. The following was clarified from the relationship between the electrode potential and current density of each of the materials in each of the solution. The alloy spheroidal graphite cast iron had a high corrosion electrode potential owing to the addition of Cu-Ni, and tended to have a low corrosion current density. This demonstrates that in any of the materials having a matrix adjusted by heat treatment, the addition of Cu-Ni increased the corrosion resistance. The corrosion current density was highest in a sulfuric acid environment.

Structural Characterization and Corrosion Properties of BTESPT Silane Films on Surface of 2024-T6 Aluminium Alloy

2007 ◽  
Vol 546-549 ◽  
pp. 1111-1116 ◽  
Author(s):  
Ming An Chen ◽  
Xuan Xie ◽  
Guo Fu Xu ◽  
Hui Zhong Li ◽  
Xin Ming Zhang
Keyword(s):  
Structural Characterization ◽  
Water Solution ◽  
Corrosion Current ◽  
Immersion Test ◽  
Alloy Sheet ◽  
Al Alloy ◽  
Entire Surface ◽  
Corrosion Properties ◽  
The Matrix

2024-T6 Al alloy sheet s were modified by bis-[triethoxysilylpropyl] tetrasulfide (BTESPT) silane film to improve the corrosion resistance. Fourier-Transform Reflection Absorption (FTIR-RA) spectroscopy was used for structural characterization of BTESPT silane film formed on surface of the sheet. Potentiodynamic polarization and immersion test in 3.5% NaCl solution were used for evaluating the corrosion performances of the silane film. The results showed that the film formed after curing at 120 °C for 40 min was cross-linked through Si-O-Si and that it was covered on the entire surface of the sheet. The content of elements S and Si on the Al2CuMg particles is a little higher that of on the matrix. The strong peak at 1032 cm-1 indicated that the film was linked to the sheet by Si-O-Al. Compared to the untreated case, the corrosion current density of the sheet treated with the silane film was reduced by close to 2 orders. Treatment of BTESPT silane can provide about 670 h protection of corrosion for the sheet in 3.5% NaCl water solution.

Tribological and Corrosive Properties of Tin/AlN Multilayer Film

2012 ◽  
Vol 560-561 ◽  
pp. 837-841
Author(s):  
Pu Hong Tang ◽  
Jie Mao ◽  
Chong You Feng
Keyword(s):  
Corrosion Resistance ◽  
Coefficient Of Friction ◽  
Gas Flow ◽  
Multilayer Film ◽  
Corrosion Current ◽  
Multilayer Films ◽  
Nitrogen Gas ◽  
Corrosion Properties ◽  
Wear Rates ◽  
The Coefficient Of Friction

TiN/AlN nanoscale multilayer films were deposited by pulsed laser ablation on silicon, with different argon and nitrogen gas flow rates. The total thickness of the TiN/AlN multilayer film was approximately 1μm. The friction and corrosion properties were studied by tribological and corrosive tests. In tribological tests, ball-on-disc was used to determine coefficients of friction and wear rates. The coefficient of friction against a Si3N4 ball varied considerably between films, as does the wear rate. The lowest coefficient of friction μ=0.97 was shown at sample 1, whereas the other three multilayer films were ranged from 1.0 to 1.5. In corrosion test, the anodic polarization characteristics were measured in a 3.5% NaCl solution at room temperature to examine the corrosion resistance. The potentiodynamic polarization measurements showed that for all the multilayer films the corrosion potential shift to higher values, and the corrosion current density decreased with increasing of nitrogen gas flow rate, which indicate a higher nitrogen partial pressures lead to a better corrosion resistance.

Effect of ECAP Pass on Corrosion Behavior of High-Al Content Magnesium Alloys

2013 ◽  
Vol 747-748 ◽  
pp. 270-275
Author(s):  
Qiang Fan ◽  
Wei Liang ◽  
Li Ping Bian ◽  
Man Qing Cheng
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Behavior ◽  
Performance Test ◽  
Corrosion Current ◽  
Second Phase ◽  
Al Content ◽  
Microstructure Observation ◽  
Angular Pressing ◽  
The Matrix ◽  
High Al Content

In view of low strength and poor corrosion resistance of Mg alloys, a Mg-12Al-0.7Si alloy was designed, fabricated and subjected to equal channel angular pressing (ECAP) in order to refine the microstructure. Microstructure observation and electrochemical performance test were conducted to investigate the influence of the microstructural variation subjected to multi-pass ECAP processing on the corrosion behavior of the alloy. The results showed that both α-Mg matrix and β-Mg17Al12of the alloy were significantly refined after processing for different passes (2,4,6,8) through route BC, and the 4-pass ECAPed alloy in 3.5% NaCl solution presents the lowest weight loss, lower corrosion current and higher corrosion potential in the polarization curves. The reason for high corrosion resistance of 4-pass ECAPed alloy and the effects of grain size of the matrix and the particle size, distribution of second phase and dynamic precipitates on corrosion behavior of the alloy were discussed.

The Influence of Heat Treatment on Corrosion Resistance of PM Composite Materials Based on EN AW-AlCu4Mg1(A) Aluminium Alloy Reinforced with the Ti(C,N) Particles

2007 ◽  
Vol 534-536 ◽  
pp. 845-848 ◽  
Author(s):  
Leszek Adam Dobrzański ◽  
Anna Włodarczyk-Fligier ◽  
Marcin Adamiak
Keyword(s):  
Heat Treatment ◽  
Corrosion Resistance ◽  
Composite Materials ◽  
Aluminium Alloy ◽  
Precipitation Hardening ◽  
Pure Aluminium ◽  
Corrosion Wear ◽  
Alloy Base ◽  
The Matrix ◽  
Base Composite

Investigation results of the heat treatment effect on the corrosion resistance of the EN AW-AlCu4Mg1 (A) aluminium alloy base composite materials reinforced with the Ti(C,N) particles with varying volume fractions are presented. Examinations were made of the EN AW-Al Cu4Mg1(A) aluminum alloy, and also of the composite materials with the matrix from this aluminium alloy. It was found out, basing on own research, that corrosion wear after the corrosion tests of the composite materials with the addition of 5% of the Ti(C,N) particles is smaller compared to the pure aluminium alloy. Precipitation hardening causes improvement of the corrosion resistance of the investigated composite materials and - like in the state before the heat treatment, materials with 5% portion of the Ti(C,N) reinforcement ratio are characteristic of more advantageous features compared to the material without the reinforcement.

Study on the Corrosion Resistance Behavior of Multi-Elements Alloy CoCrFeNiTi0.5

2014 ◽  
Vol 541-542 ◽  
pp. 61-68
Author(s):  
Sheng Jiao Pang ◽  
Ping Li ◽  
Ting Ju Li ◽  
Jie Zhao
Keyword(s):  
Corrosion Resistance ◽  
Oxide Scale ◽  
Oxide Layer ◽  
Good Adhesion ◽  
Tube Material ◽  
Protective Oxide ◽  
Good Thermal Stability ◽  
The Matrix ◽  
Internal Sulfidation ◽  
Melting Point Eutectic

Multi-elements alloy with good thermal stability is expected to serve as the superheater tube material of ultra-supercritical boiler and may suffer from hot corrosion under the coal-fired atmosphere. In this study, the corrosion resistance behavior of multi-elements alloy CoCrFeNiTi0.5 coated with alkali metal sulfates at 750°C is investigated systematically. The results showed the corrosion kinetics curves of the alloy followed a parabolic growth rate. The corrosion products, which consisted of volatile Na (CrO4) (SO4), (Fe,Ni) xSy, Cr/Ti oxide as well as compound oxides with spinel structure AB2O4, were found in the oxide scale and internal attack zone of the alloy. The oxide layer had good adhesion with the matrix at the beginning of corrosion. Prolonging corrosion time, the oxide layer in thickness increased and became loose as well as porous. The micro-pores generated in the interface between the oxide scale and matrix with the occurrence of the internal oxidation and internal sulfidation. In a word, the corrosion resistance behavior of multi-elements alloy CoCrFeNiTi0.5 at 750°C can be attributed to the formation of the protective oxide layers and to the basic fluxing in molten Na4SO4 induced by low melting point eutectic.

Optimized Thermomechanical Treatment for Strong and Ductile Martensitic Steels

2007 ◽  
Vol 539-543 ◽  
pp. 4526-4531 ◽  
Author(s):  
Araz Ardehali Barani ◽  
Dirk Ponge
Keyword(s):  
Heat Treatment ◽  
Thermomechanical Treatment ◽  
Spring Steel ◽  
Martensitic Steels ◽  
Medium Carbon ◽  
Heat Treated ◽  
Conventional Heat Treatment ◽  
The Matrix ◽  
Different Levels ◽  
Strength And Ductility

In this study the effect of thermomechanical treatment on the microstructure of austenite and martensite and the mechanical properties of a medium carbon silicon chromium spring steel with different levels of impurities is investigated. Results are presented for conventional heat treatment and for thermomechanical treatment (TMT). Compared to conventionally heat treated samples austenite deformation improves strength and ductility. Thermomechanically treated samples are not prone to embrittlement by phosphorous. TMT influences the shape and distribution of carbides within the matrix and at prior austenite grain boundaries. It is shown that utilization of TMT is beneficial for increasing the ultimate tensile strength to levels above 2200 MPa and at the same time maintaining the ductility obtained at strength levels of 1500 MPa by conventional heat treatment. The endurance limit is increased and embrittlement does not occur.

Influence of SiC Content and Heat Treatment on the Corrosion Resis-Tance and Oxidation Resistance of Ni-P-SiC Composite Coating

2015 ◽  
Vol 817 ◽  
pp. 479-483
Author(s):  
Pan Li ◽  
Wan Chang Sun ◽  
Jun Gao ◽  
Quan Zhou ◽  
Pei Zhang
Keyword(s):  
Heat Treatment ◽  
Corrosion Resistance ◽  
Composite Coating ◽  
Oxidation Resistance ◽  
Corrosion Potential ◽  
Corrosion Current ◽  
Treatment Temperature ◽  
Micro Hardness ◽  
Resis Tance ◽  
P Matrix

Ni-P alloy and SiC micron particles were codeposited on Q235 steel by electroless plating. The composition, microstructure, micro-hardness, corrosion resistance and oxidation resistance of the composite coating were studied. The results revealed that the deposited composite coating shows dispersed SiC particles and continuous Ni-P matrix. When the content of SiC was 8g/L and the heat treatment temperature was 300°C, the corrosion potential and corrosion current of Ni-P-SiC coating were-0.292V, and 8.2×10-7 A/cm2, respectively, while those of Ni-P composite coating were-0.501V, and 4.2×10-5 A/cm2, respectively. Ni-P-SiC composite coating with high content of SiC exhibits better oxidation resistance than Ni-P coating.

Ceria Coatings Prepared by Sol-Gel Approach on AZ91 Magnesium Alloy

2017 ◽  
Vol 898 ◽  
pp. 1369-1380 ◽  
Author(s):  
Hui Min Han ◽  
Dan Tong Wang ◽  
Hua Qian Yu ◽  
Min Zuo ◽  
Li Hong Wang ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Corrosion Resistance ◽  
Magnesium Alloy ◽  
Sol Gel ◽  
Electrochemical Corrosion ◽  
Chemical Conversion ◽  
Corrosion Current ◽  
Az91 Alloy ◽  
Az91 Magnesium Alloy ◽  
Az91 Magnesium

The ceria coatings on AZ91 substrates were successfully synthesized by chemical conversion and the corrosion resistance of AZ91 samples with and without ceria coatings were evaluated by means of electrochemical corrosion in 3.5 wt.% NaCl solution. According to the parameters derived from the polarization date, the Icorr (the corrosion current density) values of the coated samples are smaller than that of bare one, indicating that the corrosion resistance of AZ91 alloys has been improved to some extent. The influence of fluoridated pretreatment, inter-layer heat treatment, sintering temperature and the layer of films on the performance of ceria coatings were also investigated. It was found that the inter-layer heat treatment has no influence on improving the anticorrosion resistance of AZ91 alloy. In comparison with the bare one, the Icorr of optimal sample is about 0.0219mA/cm2, which decreases by two orders of magnitude, indicating that the ceria coatings could significantly improve the corrosion resistance of AZ91 magnesium alloy.

scholarly journals EFFECT OF HEAT TREATMENT AND PLASMA NITRIDING ON CORROSION RESISTANCE OF 440B MARTENSITIC STAINLESS STEEL

2013 ◽  
Vol 7 (3) ◽  
pp. 155-159 ◽  
Author(s):  
Magdalena Łępicka ◽  
Małgorzata Grądzka-Dahlke
Keyword(s):  
Heat Treatment ◽  
Stainless Steel ◽  
Corrosion Resistance ◽  
Plasma Nitriding ◽  
Steel Corrosion ◽  
Surgical Instruments ◽  
High Wear Resistance ◽  
Heat Treated ◽  
Conventional Heat Treatment ◽  
Steel Corrosion Resistance

Abstract Reliability and durability assurance poses a serious challenge for surgical instruments manufacturers. Hard working conditions, such as intermittent contact with body fluids and hard bone tissues, as well as necessity to undergo frequent sterilisation processes, induce constant research into solutions capable of ensuring high wear resistance while maintaining satisfactory imperviousness to corrosion. Plasma nitriding is marked as the modern corrosion resistance improving method suitable for surgical instruments steels. The paper presents findings from the heat treated and plasma nitrided AISI 440B (PN EN or DIN X90CrMoV18) steel corrosion resistance studies. Three conventionally heat treated (quenched with tempering in 250, 390 or 605°C) and three additionally plasma nitrided in N2:H2 reaction gas mixture (50:50, 35:65 and 20:80 ratio, respectively) specimens groups were examined. Furthermore, the authors evaluated the effect of machining - polishing and sandblasting - on investigated steel corrosion resistance. Microscopic observations and electrochemical corrosion tests were performed using a variety of analytical techniques. Results showed that, in comparison to conventional heat treatment, plasma nitriding of 440B stainless steel does not significantly affect its corrosive characteristics as far as the uniform nitride layer over the entire detail surface is obtained. The layer heterogeneity results in intensification of corrosion processes, making the material even more susceptible to corrosion than after conventional heat treatment, and contributing to severe, visible even with the unaided eye damages development.

Sign in / Sign up

Export Citation Format

Share Document