Pipeline steels higher than API X80 grade ad subject to hydrogen embrittlement risk induced by the hydrogen evolution effect under cathodic protection. This paper focuses on the hydrogen embrittlement behaviors of API X70, X80 and X90 high strength pipeline steel under cathodic protection in soil simulation conditions.

This paper details with the unexpected cracking encountered in the outlet nozzles of all three reactors for Platformer unit, during a scheduled shutdown. The unit was commissioned in 1957 and the reactors metallurgy is as per withdrawn ASTM standard, A301 Gr. B (1Cr-1/2Mo). The isolated cracks were located at the upstream edge of the inset nozzle and running vertically down. The cracking in the high-pressure fixed bed reactor outlet nozzles was successfully repaired in-situ. This paper reviews the circumstances which led to these failures and highlights the lessons learned from each failure.

The corrosion resistance of sucker rod materials can be a significant concern, especially in aggressive service environments with high acid gas concentrations. Corrosion-related failures have been associated with increased levels of produced hydrogen sulfide (H2S) and carbon dioxide (CO2). The presence of corrosion damage, which is characterized by local material dissolution and pitting formation under the influence of CO2 and/or H2S, provides the initiation sites in a fatigue cracking mechanism. The fatigue crack propagation in corrosion aggressive environments is associated with the following factors: (1) local tensile stress concentration at crack tip, and (2) local corrosion dissolution. Therefore, using a material that tends to re-passivate as it interacts with the environment would be the optimum solution in order to mitigate the likelihood of field failures and reduce overall operating costs. Regarding passive film disruption processes abrasion and high temperature influences were not considered at this stage of the present study and repassivation kinetics were not measured. Conventional sucker rod production processes include normalize and temper (N&T) or quench and temper (Q&T) heat treatments to meet desired strength levels of low alloy steels. In order to enhance the corrosion properties and provide a resistant sucker rod solution, 13Cr martensitic stainless steel may provide a viable alternative to low alloys steels. This paper focuses on the characterization of 13Cr sucker rod material by comparing the general corrosion and corrosion fatigue performance with low-alloy steels. 

The crevice corrosion resistance of UNS S31266 and UNS N06625 was investigated by determining their critical crevice corrosion temperatures (CCT-values) in different solutions. The crevice formers described for tubes in ISO 18070 were used. Creviced samples were tested according to ASTM G150 and ASTM G48.For the electrochemical method ASTM G150 both 1M NaCl as specified in the standard and a modified test using 3M MgCl2 were used as test-solutions. The ASTM G48-test was performed using an acidified ferric chloride solution and a testing time of 72 hours. In both the electrochemical test and in the G48-test a torque momentum of 0.28 Nm for the crevice former was compared with a torque momentum of 1.58 Nm.It was found that the CCT-values of UNS S31266 were typically higher than for UNS N06625 in all tests. Additionally the CCT-value for UNS N06625 consistently decreased when the smaller crevice gap was used. This further increased the difference in CCT-values for the two alloys to the benefit of UNS S31266 for which CCT-values were similar at 0.28 and 1.58 Nm. The difference between the alloys is compared with published results and theories.Key words: Crevice Corrosion Crevice Gap Tube UNS S31266 UNS N06625 NaCl MgCl2 Acidity Chloride Concentration

UNS N08800 alloy coupons were prepared, polished and oxidized in diluted steam at 540 ºC. Formation of carbon on the surface of the pre-oxidized samples was investigated by exposure to reducing, highly carburizing atmosphere (CO in Ar) at 20 bar and varying temperature (550- 750 ºC).

The oil and gas transmission pipelines are subject to corrosion and are regulated by governing authorities all over the world in view of public safety. Cathodic Protection (CP) is the most common technique used to protect pipelines from corrosion and is a regulatory requirement in the United States. When pipelines are installed inside casing pipe (casing) beneath roadways railroads and other locations the CP is ineffective for the cased section of carrier pipe. Furthermore when the end seals on the casing are compromised the corrosion threat is increased on the cased section of carrier pipe either due to metallic short or due to electrolytic coupling between the carrier pipe and casing. The pipeline operators in the U.S. are mandated by Congress to comply with 49 CFR Part 192 Subpart O to protect the cased carrier pipe from corrosion in High Consequence Areas (HCAs). One common approach used by pipeline operators is to fill the annulus space between casing and carrier pipe with a dielectric fill (wax). The corrosion protection with wax fill assumes that all contaminated water is pushed out of casing annulus with wax however this is not always possible. During the wax installation process contaminated water gets trapped in air pockets and around spacers consequently increasing corrosion risk on the carrier pipe. The existing indirect assessment techniques for pipeline integrity monitoring cannot be used with wax fills due to shielding effects.NACE standard SP0200 recognizes multiphase vapor corrosion inhibitors as one of the viable option for corrosion mitigation of carrier pipes in the casing annulus space. Vapor Corrosion Inhibitors (VCIs) are water based liquids that are installed in gel form in the casing annulus space. This paper explores the use of VCI gels in diverting the CP current to the holidays on the carrier pipe inside a casing and its feasibility for indirect assessment techniques used for pipeline integrity of cased pipelines.

In marine applications aluminium bronze is used extensively. The alloy IACS W24 Cu3/ CuAl10Fe5Ni5-C-GS is the most frequently used alloy for large ship propellers.Under certain conditions the material surface of ship propellers is damaged due to cavitation erosion. Cavitation erosion can be described as a hydrodynamic phenomenon which is related to the formation and collapse of gas bubbles in a liquid. The cyclic mechanical load on the material surface causes plastic deformation and material erosion. The addition of corrosive conditions can increase the material erosion.The aim of the following investigations is the understanding of the cavitation erosion behavior of aluminium bronze in artificial seawater with focus on the role of the complex microstructure.Towards this purpose vibratory cavitation tests in artificial sear water were carried out and the damage of the material surface was observed by scanning electron microscopy (SEM). In addition the corrosion behavior was investigated by exposure tests and registration ofcurrent density-potential-curves.The specimens for the investigations were taken from different parts of a large cast ship propeller: the propeller tip the center and near the hub. Within the propeller there is a significant difference regarding the grain size which is smallest in the tip and four times bigger in the hub. Due to higher strength in the propeller tip in comparison this area shows the smallest cavitation erosion damage.SEM observations showvarious mechanism of damage of the microstructure which includes the Cu-rich α-phase and different intermetallic κ -phases consisting of Al with Ni and Fe.Next step of the investigation was the variation of the standard alloy composition with focus on the Fe/Ni-relation and the Mn-content whereby the composition stays within the limits of the international standard requirements.The different alloy compositions show a significant influence on the formation of the complex microstructure of Aluminium bronze. The specimens with a high Ni-content show mainly the lamellar κ-phases between the α-grains and no round precipitations. Increasing the Fe-content leads to more round iron κ-phases and only a few proportion of eutectoid.The differences of the microstructure influence the mechanical strength and toughness the corrosion resistance and the cavitation erosion resistance of the alloy. The SEM-observations show a selective cavitation erosion and corrosion of the phases.Keywords: cavitation cavitation erosion cavitation corrosion aluminium bronze ship propellers microstructure

One of the pillars of the fourth industrial revolution (4IR) is to let machines make decisions on behalf of humans; this paper describes new technology that allows machines to decide inspection programs and field validation and testing of results. The technology described is a part of integrity management, and uses data, statistics and expert decisions to design inspection programs. These inspection programs are an important part of the safeguarding of equipment to maintain production and safety.
This technology is a data-driven predictive model of material loss from corrosion, based on domain expert input and historical data in the form of non-destructive testing (NDT) tests. The technology trends is based on historical data and SME input, while accounting for uncertainties in NDT measurements, with uncertainties in historical trends and uncertainties in future trends. This produces a more realistic failure prediction to enhance existing RBIs and adds safety by improving on early detection of trends in data. In total, this enables the machine to update inspection plans autonomously, reducing the number of inspections significantly.
The paper also describes how the technology can be developed further to use production data and integrity operating windows to improve predictions, deal with localised corrosion and assess if the test points on a corrosion circuit are sufficient, can be reduced in number or should be manually evaluated by adding more test points.

Knowledge technology provides energy companies with knowledgeable applications that help them make better decisions faster in all decision points. One such knowledge application (CrudeFlex) is related to supporting the decisions of purchasing certain crudes to be processed in certain refineries through properly evaluating the risks associated with processing such crudes.
In this paper, we discuss the basic concepts of knowledge modeling and how specifically CrudeFlex was developed as a knowledge application, how it works and how rifineries are leveraging it to strengthen their competitive edge and proactively evaluate and manage risks associated with the crudes.
The new generation of knowledge applications are powered by a combination of computational knowledge graphs and computational algorithms. These algorithms encode the expertise of subject-matter experts, such as process engineers and combine their experience with decades of historical data extracted from databases, documents, and sensors in addition to ever-growing corpus of technical research to support better decisions faster. This technology enriches and combines companies’ internal siloed data with public data to create an integrated digital knowledge layer. Engineers can evaluate and manage the risks associated with known processing and new crudes in any of their refineries.
Refining engineers have easy access to knowledge related to people, equipment, vendors, crudes and more, so that they can make better, more informed decisions faster. In this paper, we show how the application of such algorithms helps the reading of hundreds of thousands of historical reports to harvest knowledge about the risks, and store the extracted knowledge in an enterprise digital knowledge layer, saving millions of dollars by enabling experienced engineers to make significantly better decisions faster through using the harvested and captured knowledge.