The heat treatment condition of industrial materials is a critical parameter for material evaluation and its fitness for intended service. Proper heat treatment will produce desired mechanical and physical properties, while absence or improper heat treatment may lead to major failure with huge production, Environmental, Health, and Safety (EHS) impacts. We hereby explain an actual case for cracked gas compressor (CGC) 5th stage discharge line caustic stress corrosion cracking (SCC) that caused unplanned plant shut down and resulted in noticed financial and production loss.
The proven root cause is absence of normalization. Emergency piping batch is received and supposed to be normalized to avoid failure recurrence. Many discrepancies extracted from submitted material certificates, also many physical signs observed on the material itself raising doubts about received material compatibility. Using advanced Positive Material Identification (PMI) device to verify the chemical composition of the received material, results show that the material is questionable.
As a precise test to verify heat treatment condition, microstructure analysis test (metallography) conducted to confirm normalization condition of the material, the resulted grain structure size and growth confirm that one of the received pipes has improper or absence of normalization.
The material rejected as it is proven and confirmed that it is not normalized as per the requirements to avoid further potential of hydrocarbon leakage due to improper material specification. Rejecting the material eliminate the potential of having repeated failure, in addition to 600,000 Saudi Riyal (SR) cost saving as material cost. A common recommendation shared with concerned parties to consider metallography as a mandatory test to be submitted with heat-treated material test certificate (MTC).
Key words: Heat treatment, microstructure, normalization, grain structure, failure, metallography

Corrosion under insulation (CUI) is a critical challenge that affects the integrity of assets for which the oil and gas industry is not immune. Over the last few decades, both downstream and upstream industry segments have recognized the magnitude of CUI and challenges faced by the industry in its ability to handle CUI risk-based assessment, predictive detection and inspection of CUI. It is a concern that is hidden, invisible to inspectors and prompted mainly by moisture ingress between the insulation and the metallic pipe surface. The industry faces significant issues in the inspection of insulated assets, not only of pipes, but also tanks and vessels in terms of detection accuracy and precision. Currently, there is no reliable NDT detection tool that can predict the CUI spots in a safe and fast manner. In this study, a cyber physical-based approach is being presented to identify susceptible locations of CUI through a collection of infrared data overtime. The experimental results and data analysis demonstrates the feasibility of utilizing machine-learning techniques coupled with thermography to predict areas of concern. This is through a simplified clustering and classification model utilizing the Convolutional Neural Networks (CNN). This is a unique and innovative inspection technique in tackling complex challenges within the oil and gas industry, utilizing trending technologies such as big data analytics and artificial intelligence.

The failure assessment of the collapse of the Quebec Bridge in 1907 conducted by the Royal Commission is discussed in the following paper. The Quebec Bridge is a 987.5 m long; 29 m wide; and 104 m high riveted steel truss structure which collapsed not once but twice during construction. The reason for the bridge failure was attributed to member behavior and stability proved by experimental work conducted following the collapse by Royal Commission. The bridge was finally completed in 1917 and has been in operation since then. The lessons learned from the bridge collapse were pivotal in the advancement of engineering design, fabrication and formation of the two organizations, namely - the American Association of State Highway and Transportation Officials (AASHTO) in 1914 and American Institute of Steel Construction (AISC) in 1921. The author highlights the importance of validating the design criteria and specifications by material and load testing, conducting peer reviews, design control, and paying attention to details. The lessons learned reinforce the need to establish and monitor shop fabrication practices, inspection procedures and gates (witness, hold and review points) to safely complete the execution of any civil engineering project, be it onshore or offshore construction.