Some Corrosion Effects in Accelerated Cavitation Damage

1960 ◽  
Vol 82 (4) ◽  
pp. 795-802 ◽  
Author(s):  
W. C. Leith ◽  
A. Lloyd Thompson
Keyword(s):  
Fatigue Limit ◽  
Corrosion Fatigue ◽  
Field Experience ◽  
Cavitation Damage ◽  
Chemical Destruction ◽  
Metallurgical Structure ◽  
Hydraulic Turbines ◽  
Diesel Cylinder ◽  
Metal Properties ◽  
Cylinder Liners

The conjoint mechanical-chemical destruction of metals by accelerated cavitation in a magnetostriction apparatus indicates relative effects of the metal properties (hardness, metallurgical structure, corrosion-fatigue limit) and of the liquid characteristics (temperature, pressure, wettability) which have been confirmed by field experience in hydraulic turbines and in water-cooled diesel cylinder liners.

Crack Growth Rates and Corrosion Fatigue of Austenitic Stainless Steels in High Chloride Solutions

2011 ◽  
Vol 488-489 ◽  
pp. 97-100 ◽  
Author(s):  
Clemens Vichytil ◽  
G. Mori ◽  
Reinhard Pippan ◽  
M. Panzenböck ◽  
Rainer Fluch
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Crack Propagation ◽  
Crack Growth ◽  
Fatigue Limit ◽  
Corrosion Fatigue ◽  
Stainless Steels ◽  
Austenitic Stainless Steels ◽  
Propagation Rate ◽  
Corrosive Environment

Purpose: Applications for highly corrosive environments and cyclic loading are often made out of austenitic stainless steels. Corrosion fatigue and crack propagation behaviour has been studied to determine failure processes and damage mechanisms. Approach: CrNiMo stabilized austenitic stainless steel and CrMnN austenitic stainless steel in solution annealed and cold worked condition are compared. S/N curves and crack propagation rate curves are recorded in 43 wt% CaCl2solution at 120 °C, which resembles most severe potential service conditions. For comparison these experiments are also performed in inert glycerine. Additionally, the electrochemical behaviour of these materials has been studied. Findings: The CrMnN steels have excellent mechanical properties but are very susceptible to stress corrosion cracking in the test solution. The fatigue limit as well as the threshold for long crack growth are significantly reduced in corrosive environment. Moreover these steels exhibit a remarkable increase in the propagation rate, which is extremely pronounced in the near threshold region. This effect is enhanced by cold working. CrNiMo steels also show a reduction in the fatigue limit, but it is less pronounced compared to CrMnN steels. The threshold is significantly reduced in corrosive environment, but propagation rate is lower in corrosive environment compared to inert glycerine. Possible explanations of this surprising behaviour are discussed.

scholarly journals Corrosion-Fatigue Evaluation of Uncoated Weathering Steel Bridges

2019 ◽  
Vol 9 (17) ◽  
pp. 3461 ◽  
Author(s):  
Yu Zhang ◽  
Kaifeng Zheng ◽  
Junlin Heng ◽  
Jin Zhu
Keyword(s):  
Crack Propagation ◽  
Fatigue Limit ◽  
Corrosion Fatigue ◽  
Weathering Steel ◽  
Faraday’S Law ◽  
Critical Flaw ◽  
Initiation Stage ◽  
Fatigue Evaluation ◽  
Corrosive Environments ◽  
Propagation Stage

Uncoated weathering steel (UWS) bridges have been extensively used to reduce the lifecycle cost since they are maintenance-free and eco-friendly. However, the fatigue issue becomes significant in UWS bridges due to the intended corrosion process utilized to form the corrodent-proof rust layer instead of the coating process. In this paper, an innovative model is proposed to simulate the corrosion-fatigue (C-F) process in UWS bridges. Generally, the C-F process could be considered as two relatively independent stages in a time series, including the pitting process of flaw-initiation and the fatigue crack propagation of the critical pitting flaw. In the proposed C-F model, Faraday’s law has been employed at the critical flaw-initiation stage to describe the pitting process, in which the pitting current is applied to reflect the pitting rate in different corrosive environments. At the crack propagation stage, the influence of pitting corrosion is so small that it can be safely ignored. In simulating the crack propagation stage, the advanced NASGRO equation proposed by the NASA is employed instead of the classic Paris’ law, in which a modified fatigue limit is adopted. The fatigue limit is then used to determine the critical size of pitting flaws, above which the fatigue effect joins as a parallel driving force in crack propagation. The model is then validated through the experimental data from published articles at the initiation stage as well as the whole C-F process. Two types of structural steel, i.e., HPS 70W and 14MnNbq steel, have been selected to carry out a case study. The result shows that the C-F life can be notably prolonged in the HPS 70W due to the enhancement in fatigue strength and corrosion resistance. Besides, a sensitivity analysis has been made on the crucial parameters, including the stress range, stress ratio, corrosive environment and average daily truck traffic (ADTT). The result has revealed the different influence of the above parameters on the initiation life and propagation life.

Effect of structure on the wear of quenched martensitic cast iron for diesel cylinder liners

1990 ◽  
Vol 32 (12) ◽  
pp. 931-934
Author(s):  
B. M. Astashkevich ◽  
O. M. Eparkhin ◽  
G. A. Maznova
Keyword(s):  
Cast Iron ◽  
Diesel Cylinder ◽  
Cylinder Liners ◽  
Effect Of Structure

Dependence of Corrosion Fatigue Crack Initiation Mechanisms on the Corrosion Behavior of Two Stainless Chromium Steels

CORROSION ◽  
1982 ◽  
Vol 38 (8) ◽  
pp. 431-436 ◽  
Author(s):  
Matthias P. Mueller
Keyword(s):  
Fatigue Crack ◽  
Crack Initiation ◽  
Fatigue Limit ◽  
Corrosion Fatigue ◽  
Chloride Solution ◽  
Sodium Chloride Solution ◽  
Fatigue Crack Initiation ◽  
Chromium Steel ◽  
Corrosion Attack ◽  
Corrosion Fatigue Crack

Abstract Corrosion fatigue experiments have been carried out in a 0.5N and 4N sodium chloride solution with pH of 6.5 at 80 C. The solution has been air saturated. Two different chromium steels were examined, a tempered martensitic steel with 12% chromium and a pure ferritic steel with 18% chromium and 2% molybdenum. The results of this investigation showed that the corrosion fatigue crack initiation mechanisms are directly related to the type of corrosion attack. Under pitting corrosion conditions, a pronounced decrease in fatigue limit has been measured. Under passive corrosion conditions, a corrosion fatigue limit exists, which could be related to the thickness of the passive surface film and the surface slip characteristics of the alloy. It has been shown that under passive corrosion conditions, the corrosion fatigue limit cannot be lower than the cyclic yield strength of the material. Nonmetallic inclusions were found to play an important role in corrosion fatigue crack initiation. In the 12% chromium steel, sulfide inclusions acted as pit initiation sites. Chemically inert niobiumcarbonitrides in the 18% chromium steel induced local corrosion attack, but only under corrosion fatigue conditions in the 4N sodium chloride solution.

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