General Poster Session: Corrosion
Program Organizers: TMS Administration

Monday 5:30 PM
February 24, 2020
Room: Sails Pavilion
Location: San Diego Convention Ctr


Cancelled
C-14: Development of Ni-based Amorphous Coating for the Prevention of Hydrogen Embrittlement in Line Pipe Grade Steels: Santigopal Samanta1; Charu Singh1; Kallol Mondal2; Amar Bhagat1; Monojit Dutta1; Shiv Brat Singh3; 1Tata Steel Limited; 2Indian Institute of Technology Kanpur; 3Indian Institute of Technology Kharagpur
    Materials have been observed to fail abruptly at a lower than designed fracture toughness due to the presence of hydrogen. The phenomenon is commonly known as hydrogen embrittlement (HE) and is known for the last 140 years. Few ppm levels of hydrogen have been observed to cause HE. This tiny quantity comes typically from corrosion during service. Stronger steels, particularly in energy industries, are susceptible to it. Numerous coatings have been developed to effectively retard hydrogen ingress during service and thereby prevent HE. In the present work, Ni-based amorphous coating is proposed as a formidable hydrogen barrier which not only reduces hydrogen ingress in service but also serves as a corrosion resistant coating. The coating is applied over line pipe grade steel substrate following electroless method. Electrochemical hydrogen permeation tests reveal a very low hydrogen permeation properties. Slow strain rate tensile tests show the effective reduction in hydrogen embrittlement susceptibility.

Cancelled
C-15: Enhanced Passivation Layer by Cr Diffusion of 301 Stainless Steel Facilitated by SMAT: Temitope Olugbade1; Chang Liu1; Jian Lu1; 1City University of Hong Kong
    AISI 301 stainless steel (SS) is known for its high strength and hardness but tends to be less corrosion resistant for many applications. Several attempts have been made in the past to investigate its corrosion behaviour by different methods. However, current knowledge is insufficient on its corrosion resistance when subjected to surface treatment. In this work, a new route to enhance the corrosion resistance of nanostructured 301 SS using surface mechanical attrition treatment (SMAT) method is described. Compared to the as-received 316 and 304 SS counterparts, the present nanostructured 301 SS exhibits an improved corrosion behaviour by a lower corrosion current density, higher corrosion potential, and Cr content. The improved corrosion resistance can be attributed to the ability of SMAT to facilitate the move of Cr on the surface, which forms a stronger passivation layer with a new mechanism of passivation that may save a lot of noble metals.

C-16: Mechanical Testing and Tomography of Crack Development in 5XXX Aluminum Service Material: Benjamin Palmer1; Visweswara Gudla2; John Lewandoski1; 1Case Western Reserve University; 2University of Manchester
    The desirability of 5XXX series Aluminum-Magnesium alloys for Naval use is tempered by their propensity to develop Intergranular Stress-Corrosion Cracking (IGSCC). This promoted by the precipitation of an anodic β phase (Al3Mg2) along grain boundaries with thermal exposure, especially for long times at service temperatures. To study the effects of service exposure on sensitization and cracking, 5083 Aluminum from a ship with over four decades of field exposure is examined herein. This work specifically focuses on the interaction of cracking with the microstructure and environment, and tracing the development of cracks with high-resolution tomography.

C-17: Replicating Corrosion in Gas Turbine Engines: Abigail Ackerman1; Ben Wood1; Stella Pedrazzini1; 1Imperial College, London
    Corrosion is currently a significant problem within engineering. The corrosion of Ni superalloys in particular has been a large subject of study in recent years. The presence of SO2/3 within gas turbine engines, as a product of exhaust emissions, volcanic activity and the ingestion and high temperature oxidation of H2S is not yet understood. The production of SO2, its conversion to SO3 (with or without catalytic activity), the effect of moisture and/or salt on the materials within the turbine is known to be negative, but requires further investigation. Here, we show a novel gas exchange rig, that combines moisture and SO2/SO3 to replicate the service environment of a gas turbine engine. This is used in combination with salted specimens to perform fatigue tests at temperature in order to gain a more complete understanding of superalloy corrosion.

C-18: The Role of Composition and Microstructure on the Cyclic Oxidation Kinetics of IN738LC, N5 and Rene 80: Mallikarjuna Heggadadevanapura Thammaiah1; Norman Richards1; William Caley1; 1University of Manitoba
    The cyclic oxidation behaviour of IN738LC, Rene 80 and N5 was investigated. The test consisted of 1000 cycles of 1 h exposure in static air at 900°C using a discontinuous thermogravimetric method. The cyclic oxidation resistance of N5 was found to be better than that of IN738LC and Rene 80; also, scale spallation for N5 was minimal compared to the other two alloys. Although both IN738LC and Rene 80 showed scale spallation, the rate was more severe in Rene 80 due to the combined effects of high Ti and formation of volatile Mo-rich oxides. The spallation in N5 was due to the formation of Ta-Hf-oxy carbides, which generate a high shear strain at the matrix-oxide and oxy-carbide interface. A COSP-Monte Carlo simulation was found to provide a reasonable fit for IN738LC, whereas the approach was less applicable in Rene 80 and N5 due to severe and unpredictable spallation respectively.