... that contribute to the formation of corrosion pits were investigated. Four different sucker rod materials were evaluated with respect to (1) chemistry, (2) nonmetallic inclusion content and (3) microstructural investigation including banding severity. It was concluded that microstructural banding has a negative...

... with the CPT of the same alloy which was obtained using the Zero Resistance Ammeter in other solutions including ferric chloride and using anodic polarization at different temperatures in 0.6 M NaCl solution. CRA DSS ECN Pitting CPT Ferrite Austenite Inclusions Precursor Sites Heat Treatment...

... Inclusions Precursor Sites Heat Treatment Temperature Annealing Temperature Electrochemistry Metastable Pitting Pit Initiation INTRODUCTION The qualification of materials for their use in harsh environments, particularly in the oil and gas industry, requires new techniques and methodologies that can...

.... The analysis shows that microstructural banding is not a contributor to HIC behavior of A516 carbon steel plates. Scanning Electron Microscopy (SEM) analyses of opened HIC cracks was used to identify HIC initiation sites in some of the plates. Non-metallic inclusions - both sulfides and oxides - were...

... inclusions - both sulfides and oxides - were identified as the primary sources of high CLR values in HIC tested samples. These microstructural features, rather than the banding index per se, are the causal factors of HIC in pressure vessel steels. Carbon steel hydrogen induced cracking (HIC...

... by oil or water quenched). A second heat treatment to release the stresses originating from machining or welding may be used in some alloys. Therefore, the size of the ferrite and the size of the austenite grains (microstructure), ferrite-to-austenite ratio, and inclusions will have an impact...

... dark features inside the photomicrographs correspond to the inclusions in the samples (this will be discussed below). Following polishing and etching, some samples were imaged using a conventional optical microscope to select the areas to be analyzed. The ferrite matrix and austenite grains were...

... between the reaction rate driven by the environment and the rate of mechanical damage from cyclic loading. The article’s goal is enabling the reader to understand the roles inclusion and pitting play on CF crack initiation. The effects stress and frequency retain on CF damage are explained utilizing...

... sites for pitting corrosion on the 25 Cr DSS sample. In-situ Electrochemistry DSS Pitting CPT Ferrite Austenite Inclusions Precursor Sites INTRODUCTION In-situ micro visualization of the surface changes during the corrosion process of corrosion resistant alloys (CRAs) can have a wide...

... and replaced. An investigation was thus conducted to understand the nature and mechanism of the unusual corrosion/cracks on this concerned pipeline. Metallurgical characterization identified the anomalies on the surface to be corrosion along manganese sulfide (MnS) inclusions, and SCC subsequently occurred...

... an electrochemical cell. The results shows that the precursor sites for pitting on 25 Cr DSS are very complex in nature. The larger inclusions within several areas analyzed and tested did not undergo pitting corrosion, in some cases at much higher temperatures than the Critical Pitting Temperature (CPT). However...

... not undergo any type of corrosion at the lower temperature (40 °C) in this test, the same sample was used at the higher temperature (180 °C). As it can be seen in the image, the dark region corresponds to the ferrite matrix, whereas the lighter grains correspond to the austenite grains. A few inclusions...

...It is well established that MnS inclusions are the main cause of pitting in commercial stainless steels ^{2 - 5} . However, in highly alloyed materials, like in the case of corrosion resistant alloys (CRAs), the cause for pitting is a more complex phenomenon, mainly because of the presence...

... for either the Alloy 600MA or Alloy 600TT tubes. Steam generator stress corrosion cracking Alloy 600 heat transfer crevices secondary side inclusions stringers INTRODUCTION Alloy 600MA Freespan ODSCC Steam generators in the pressurized water reactor (PWR) power plants contain thousands of long thin...

... C110 casing premium connections inclusions INTRODUCTION The issue of SSC has been a key topic in the oil industry for quite sometime. ¹ In regard to tubular casing, the greatest importance has been placed on controlling SSC susceptibility through metallurgical factors such as hardness...

...) decreased, and the susceptibility to hydrogen-induced cracking increased as a consequence. Sulfide stress cracking HIC inclusions hydrogen permeation hydrogen diffusion alloying elements linepipe steels INTRODUCTION Numerous research results have been published on the hydrogen embrittlement of carbon...

... foster MIC in these locations. Mitigation strategies treating material selection and weld process/procedure selection are discussed. Low Alloy Steel Microbiologically Influenced Corrosion Pitting Microstructure Welding Inclusions Analysis of Variance INTRODUCTION Since the turn of the century MIC...

... to the experimental data. Hydrogen HIC cracking permeation ultrasonic inspection modelling fracture toughness inclusions segregation micro structure INTRODUCTION During the permeation experiments, the growth of HIC defects was followed by repeatedly scanning an area of the membrane ¹⁷ . A step...

...In aerobic systems, the causal relationship between inclusions and pitting has been well established, if not well understood, for many years. Less clear are the mechanisms for pitting observed in anaerobic, biologically active systems. The effect of sulfide inclusions as privileged sites...

..., and the likelihood of cracking decreases when the clearance between two surfaces is greater than about 0.04 mm (0.001 in.). Crack initiation has been found to be independent of disc steel composition, inclusions, and pitting, although cracks may be initiated at pits formed on steel surfaces at inclusions. While...