Risk Based Inspection & Test Methods Session
 
18 August, Thursday - Sabah Room - 10:45am - 12:30pm

Chair : Tuan Haji Kamal Azam, PETRONAS GTS

RBI Approach to Manage Accelerated Sulfidation Corrosion Risk in Low Si Carbon Steel Piping

18 August, Thursday - Sabah Room - 10:50am - 11:20am

Bio of Speaker

Abstract

Carbon steel is the most commonly used material in the refinery for process piping because of ease of fabrication, good mechanical properties, availability and cost effectiveness. Several grades of carbon steel piping have been used in older refineries with the most common grades being A-106, A53, API 5L Gr B etc.  It is used in sulfidation corrosion environment also. The one key element for reliable operation of carbon steel in a sulfidation environment is the presence of silicon typically more than 0.1 wt%. Silicon content imparts significant resistance to sulfidation corrosion for carbon steels in the 260-342°C range. There is no minimum requirement of silicon specified by ASME for material like A53, API 5L Gr B etc. Carbon steel having less than 0.1 wt% silicon, can experience accelerated corrosion in sulfidation service starting around 260°C. Positive material identification techniques have been generally used for alloy steel materials and not for measurement of Si content in carbon steel.  As a result, there have been numerous failures and process safety incidents experienced in the refining industry. A risk based inspection approach was adopted in order to prioritize and effectively manage the risk of accelerated sulfidation corrosion in piping operating at elevated temperature and susceptible to have low Si carbon steel sections especially for the units constructed before 1980s. This paper will talk about risk based approach adopted, inspection methods, findings and techniques used to make process more efficient.

Atmospheric corrosion behaviors of steels in Japan

18 August, Thursday - Sabah Room - 11:25am - 11:55am

Bio of Speaker

Abstract

Name:  Tadashi Shinohara
Title / Position:  Dr. of Eng./ Special Researcher
Company:  National Institute for Materials Science
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​T. Shinohara was educated in the University of Tokyo and was gave Dr. degree from the University of Tokyo in 1985. He worked as Research Associate (1985~1988), Lecturer (1988~1992) and Associate Professor (1992~2002) in the University of Tokyo. He moved to the National Institute for Materials Science, NIMS, and worked as the Group Leader of Corrosion Group from April, 2002 and retired in March, 2015. Now, he is the Special Researcher of Corrosion Group at National Institute for Materials Science from April, 2015. He is responsible for the atmospheric corrosion of metals and localized corrosion of stainless steels.
At present, the mainstream method of classifying environmental corrosion is that specified in ISO 9223. This is a method in which the corrosion rates of various metals are classified in 6 levels based on the results of direct exposure tests conducted at 52 locations around the world. However, because the exposure sites are located mainly in the European region, standardization of an evaluation/classification method suited to the Asian region has been strongly desired. Therefore, exposure tests were conducted in three counties, Japan, Vietnam and Thailand, under “e-Asia Project”. In this paper, the exposure test results for carbon steel and weathering steel in Japan are reported. Exposure tests were conducted at 13 sites in Japan. For the environmental factors, monthly amounts of airborne salinity, S, and SOx were measured by “Dry gauze” and “PbO2 cylinder”, respectively, based on JIS 2382. The temperature, relative humidity, RH, and ACM sensor output, I, were recorded in a microcomputer every 10 min.
The values of corrosion rate of carbon steel, CR[CS], increased with increasing temperature, T, where T>10˚C, while the CR[CS] values slightly increased with decreasing T where T<10˚C. The CR[CS] values were affected by airborne salinity, S, where S>0.03mdd, while they were not affected by S where S<0.03mdd. The dependence of CR[CS] on S was stronger in the Pacific side and Inland than in Japan sea side. It was also confirmed that corrosion rate of weathering steel was almost same to that of carbon steel during 1year exposure.

Cathodic Disbondment Testing of Pipeline Coatings: Influence of Test Parameters

18 August, Thursday - Sabah Room - 12:00pm - 12:30pm

Bio of Speaker

Abstract

Name: Dr. Smita Kumari
Title / Position:  Head-Quality Assurance and Control (Coating)
Company:  Welspun Corp Ltd

Dr. Smita Kumari has more than 8.5 years valuable experience in Protective Coating, Quality Assurance, Material Selection, and Product Development of Polymer based sealants/coatings for corrosion protection. She is a doctorate in Corrosion Science and Engineering from Indian Institute of Technology Bombay India
She was the key person in development of customized Protective Coatings for several industrial applications (Anti-corrosion impact-resistant coating for Indian Railways, Underwater Coating for offshore structures, etc.) while working with EWAC Alloys, Larsen & Toubro. She has hands on experience of Laser Coating, Thermal Spray Coating, Linepipe Coating and in manufacturing of Nickel-alloy powders by Water Atomization System. She has also worked in Hydrocarbon Upstream projects as coating expert and has good knowledge of protective coatings for offshore structure. Currently she is working with Welspun Corp Ltd as Head-QA/QC of Coating plant. Welspun Corp Ltd Coating plant has facilities of 3LPO coating, FBE/DFBE coating, gas flow coating and other internal coatings of pipes.
Apart from this, Dr. Smita was part of Indian delegates team for International Visitor Leadership Program on “Adoption of American Anti-corrosion Standards” The delegates visited various industries and establishments related to corrosion on invitation of US Department of States. Dr. Smita Kumari is a Qualified QMS Auditor / Lead Auditor (based on ISO 9001:2008). She is also associated with FICCI (Federation of Indian Chambers of Commerce & Industry) Quality Systems Excellence Award for Manufacturing as an Auditor since last three years.
  
Cathodic disbondment (CD) test is one of the most versatile methods to assess performance of external polymeric pipeline coatings when installed in service under cathodic protection. Currently a large number of standardized test methods for CD test are available with a wide range of variations in test parameters. The test parameters which mainly influence the results and hence, analysis of CD tests are applied potential, electrolyte concentration, dry film thickness, drill hole dimensions, temperature, duration of test, oxygen concentration in electrolyte, field (for e.g. temperature) simulation methodology, etc. Under the influence of such parameters, similar test results cannot be predicted when performed in different laboratories, even after following identical test methods.
The present paper discusses importance and effect of influencing test parameters on cathodic disbondment of 3LPO coatings. In this study, different test parameters as specified in various standardized test methods as well as based on requirement of field conditions were used in CD testing of 3LPE and 3LPP coatings and the results were co-related with effect of applied parameters. The valuable insight of parameters of CD test can be helpful in the interpretation of test results and hence, in relevant transferability of laboratory test results to field conditions.