Quality Engineering ensures that a quality product is fabricated, by utilising engineering and inspection knowledge through the complete project lifecycle. SecMet’s dedicated inspection personnel are supported by a team of metallurgical and welding engineers to ensure the quality of engineering fabrications by performing amongst others, dimensional checks, material identification, the applicability of welding and heat treatment procedures as well as compliance to the relevant design codes and occupational health and safety legislation.
Compliance verification
Core capability of this discipline includes:
Highly qualified professionals in the field of fabrication and weld inspection as the team consist out of metallurgists, inspectors of pressurised equipment (IPE’s) and quality control inspectors.
Ensuring that all Legislative, Statutory, Health and Safety Standard and Client Specific Specifications are adhered to during project execution.
Legislative Compliance:
Occupational Health and Safety Act: Pressure Equipment Regulation
Engineering integrity assessments utilize inspection and non-destructive surveys to assess the current condition of the equipment being studied. Often, such surveys are risk-based, where high-risk equipment is prioritized through a process of analysis referred to as Risk-Based-Inspection (RBI) Assessment. In the petrochemical industry API 580 is the recommended practice that guides equipment owners on the key elements, benefits and limitations of RBI. The process is mechanical integrity focused and identifies probabilities of failure and the consequences of failure into a risk matrix. Risk mitigation activities are defined and typically equipment within the very high risk zone are considered replacement candidates. The RBI program generally documents the methodology for managing the risk through inspection, maintenance and mitigation activities.
The risk matrix
Continuous improvements on Corporate Management Policies, Inspection Management Systems (IMS) and Risk Based Inspection (RBI) procedures are important to ensure proper asset integrity. Any review of these policies and processes should also include assessment of the pressure equipment procurement and repairs processes as well as engineering change procedures for any shortcomings. By performing gap analyses or benchmarking these policies and procedures against best international practices, the successfulness of the systems and procedures can be augmented. These systems will assist in providing information for asset replacement strategies as well as maintenance plans and costs.
Forensic Engineering are primarily concerned with the correct reconstruction of an incident which resulted in failure, loss, injury or death. As such, Forensic Engineering is also often utilized in investigations with a commercial or industrial focus. Engineering knowledge, concepts and techniques are used in order to arrive at the required reconstruction.
The forensic engineer meticulously investigates accidents and failures with the objective of establishing causation and the sequence of events leading to the accident. This work can also be utilized by the legal profession for both civil and criminal court proceedings.
Reconstructing the sequence of failure events of a reclaimer collapse
Due to the increasing complexity of plants and the high cost of capital equipment, a failure of a critical item of equipment could amount to many millions of Rand in terms of lost production and equipment replacement costs, not to mention the possibility of lost lives.
In order to prevent a failure from re-occurring, it is essential that a thorough understanding of the root cause of the failure be gained. SecMet has conducted countless failure investigations over the years, which range in complexity from a relatively simple fatigue failure of a shaft to explosion of pressurized equipment and collapsed bridges which resulted in fatalities, and as a consequence have developed comprehensive competence in this field.
Corrosion Engineering is the specialist discipline of applying science and technology to prevent or control corrosion damage economically and safely. Corrosion engineering often includes design and implementation of materials, structures, devices, systems and procedures to manage corrosion. Corrosion may be defined as the destruction or deterioration of a material due to interaction with its environment.
Metallurgical engineers can apply their knowledge of the chemical, metallurgical, physical and mechanical properties of materials to evaluate material performance under laboratory simulated conditions in aggressive environments.
Cross-sectioned boiler tube with pitting corrosion
Mass Loss Corrosion Testing
Mass loss corrosion testing provides a cost-effective means of identifying potential problem areas in new plants and for evaluating alternative materials or protective coating system(s) and/or to quantify existing corrosion problems.
Corrosion coupon
Corrosion coupon preparation and test procedures are performed in accordance with ASTM and NACE standards. Mass loss tests are usually accompanied by semi-quantitative analyses of the corrosion product using a scanning electron microscope with energy dispersive spectrometry which is performed inhouse at SecMet (Pty) Ltd. This facilitates the identification or confirmation of the corrosion mechanism involved, thus providing a powerful corrosion management tool to our clients.
or environments where SCC and/or hydrogen embrittlement (HE) are prevalent, the in-situ testing of pre-stressed SCC coupons in order to select the most suitable material for future replacement of the components or vessel shell is advisable. Typical specimens include C-ring and compact tension (CT) samples. The CT coupons are typically pre-cracked and stressed to predetermined Crack Tip Opening Displacement (CTOD) value. The post-exposure assessment comprised assessment of the CT specimen sides and fractured surface to determination the nature and extent of crack propagation experienced during exposure testing.
Welding engineering involves the development of welding techniques, procedures and the application of welding knowledge for solving and optimising manufacturing and welding related challenges.
SecMet’s capabilities extend from the development and testing of welding procedures according to recognised specifications and codes, to the assessment of welders and development of post weld heat treatment procedures. In-house testing allows SecMet to be a one stop Welding engineering solution provider
In addition, SecMet can provide welding expertise in the form of weld related failure and forensic investigations.
SecMet commonly qualifies Welding procedures to the following specifications or codes:
Boiler condition assessment surveys are aimed at quantification of the current condition of boiler components and the estimation of the remaining safe operating life. A combination of non-destructive evaluation, post-exposure thermo-mechanical testing and metallographic evaluation is utilized to determine the current condition of the material. Non-destructive evaluation reveals life-limiting damage mechanisms, of which the rate determining factors are subsequently quantified through post-exposure testing and/ or metallography.
Waste Heat Boiler
The most prevalent degradation mechanisms associated with boilers are creep, softening and metal loss. SecMet’s suitably qualified personnel and extensive experience in creep testing and assessment, enables the accurate in-house evaluation of replicas, classification of microstructures and measurement of scale deposits in accordance with internationally accepted creep and softening classification systems.
SecMet’s world-class creep testing enables determination of creep life expended and remaining safe operating life. A combination of experimental and calculative procedures is used, in accordance with internationally accepted methods. Our many satisfied clients globally can attest to the financial benefits resulting from our boiler condition surveys.
Creep
The slow and continuous deformation of metals at high temperatures below the yield stress is defined as creep. Therefore, it is a time dependent deformation process of a stressed component and all metals and alloys are susceptible to it. Creep behaviour is relevant above four-tenths of the melting point (0.4 Tm).
Fitness-For-Service assessments are quantitative engineering evaluations that are performed to demonstrate the structural integrity of in-service components that may contain a flaw or damage at specific operating conditions. The FFS approach provide technically sound, conservative and meticulous solutions to ensure the safety of plant personnel and the public in an environment where aging equipment continues to be operated. The additional benefits of FFS assessments are that they provide inputs for decisions to continue to run, alter, repair, monitor, retire or replace equipment. Often a rerating or reduction in operating temperature or pressure can allow components to be returned to service. It is customary to compliment FFS assessment with a Remaining Life Assessment (RLA).
Pipe elbow stress distribution following FEA analysis
Straight-forward and conservative calculations are occasionally found in design or construction codes for certain deviations or manufacturing flaws. However, API 579-1/ASME FFS-1 allows for a more sophisticated assessment of metallurgical conditions and analyses of local stresses to conclude if equipment is fit for its intended service or whether particular fabrication defects or in-service degradation threatens its integrity. Accordingly, the active degradation mechanisms are identified as a first step. Theoretical and practical knowledge of the degradation process are then combined with knowledge of materials and structural behaviour to establish if continued operation is feasible and safe.
SecMet is well positioned and experienced with regard to Fitness-For-Service and Remaining Life assessments. We make use of leading standards and documents such as BS 7910, API 579-1 / ASME FFS-1, 2016 and specialist software in this regard. Our strong metallurgical and materials engineering background, combined with state-of-the-art structural modelling and testing capabilities, results in word-class Fitness-For-Service assessments.
Forensic Engineering is primarily concerned with the correct reconstruction of an incident which resulted in failure, loss, injury or death. As such, Forensic Engineering is also often utilized in investigations with a commercial or industrial focus. Engineering knowledge, concepts and techniques are used in order to arrive at the required reconstruction.
The forensic engineer meticulously investigates accidents and failures with the objective of establishing causation and the sequence of events leading to the accident. This work can also be utilized by the legal profession for both civil and criminal court proceedings.
Reconstructing the sequence of failure events of a reclaimer collapse
Due to the increasing complexity of plants and the high cost of capital equipment, a failure of a critical item of equipment could amount to many millions of Rand in terms of lost production and equipment replacement costs, not to mention the possibility of lost lives.
In order to prevent a failure from re-occurring, it is essential that a thorough understanding of the root cause of the failure be gained. SecMet has conducted countless failure investigations over the years, which range in complexity from a relatively simple fatigue failure of a shaft to explosion of pressurized equipment and collapsed bridges which resulted in fatalities, and as a consequence have developed comprehensive competence in this field.
Serviced and calibrated equipment for spectroscopy, mechanical, metallographic and limited corrosion testing are available at our laboratories, including a state-of-the-art Scanning Electron Microscope (SEM), which enables accurate identification of failure mechanisms, metallographic structures and corrosion products.
Joel Scanning Electron Microscope
Metallurgical sample preparation facilities sourced from Leco and Struers are available at both laboratories, allowing for the mounting and polishing of various type of metals and subsequent etching (a technique to reveal the microstructure of materials) using various reagents or, if required, electrolytically. The evaluation of the microstructures is facilitated via Olympus GX51 microscopes with digital cameras and specialist metallurgical imaging software.
In addition to the fixed laboratory equipment, an array of portable equipment for on-site spectroscopy analysis (chemical composition), metallographic replication, hardness, temperature, wall thickness and coating thickness measurement are used by well trained technicians under supervision of experienced site managers.
Portable metallurgical and recording equipment
List of Secmet’s laboratory tests and services:
Spark emission spark spectroscopy (analyse the chemical composition of metallic samples through the application of an electric arc or spark)
Microscopy assessments (Optical, Stereo and Scanning Electron Microscopy)
Machining and cutting facilities
Mechanical testing:
Creep testing (Omega and accelerated creep rupture testing)
Tensile testing
Bend testing
Impact testing
Fracture toughness testing
Micro and bulk hardness testing (Brinel, Vickers and Rockwell B and C as well as superficial scales are offered)
Flattening and flaring tests
Electrochemical testing
Metallographic assessment of ferrous and non-ferrous materials including delta ferrite assessments.
Cleanliness of steel assessments
Grain size determination
Macro-etching
Gravimetric assessment of metallic coatings
Coating thickness assessments
Detection of detrimental Intermetallic Phase in Duplex Austenitic/Ferritic Stainless Steels in accordance with ASTM A923
Intergranular corrosion assessments in accordance with ASTM A262, practice ‘E’
Furnaces for material heat treatment, allowing for the quantification of material degradation with repeated PWHT cycles, Holloman-Jaffe calculations as well as heat treatment trails
Replication assessments
Compression and tensile testing
Tensile Testing
In addition to two in-house tensile testing machines, one with high load capacity (600kN) and one suitable for testing small samples at relatively low loads, a co-operation agreement with a local research institute provides access to servo-hydraulic testing equipment for advanced fracture mechanics testing.
Compression and 4 point bend testing are also offered by SecMet.
