Steel Equipment Research Articles

Seismic behavior of steel column-base-connection equipped by NiTi shape memory alloy

The behavior of moment resistant steel structures depends on both the beam-column connections and columns foundations connections. Obviously, if the connections can meet the adequate ductility and resistance against lateral loads, the seismic capacity of these structures will be linked practically to the performance of these connections. The shape memory alloys (SMAs) have been most recently used as a means of energy dissipation in buildings. The main approach adopted by researchers in the use of such alloys is firstly bracing, and secondly connecting the beams to columns. Additionally, the behavior of these alloys is modeled in software applications rarely involving equivalent torsional springs and column-foundation connections. This paper attempts to introduce the shape memory alloys and their applications in steel structural connections, proposing a new steel column- foundation connection, not merely a theoretical model but practically a realistic and applicable model in structures. Moreover, it entails the same functionality as macro modeling software based on real behavior, which can use different materials to establish a connection between the columns and foundations. In this paper, the suggested steel column-foundation connection was introduced. Moreover, exploring the seismic dynamic behavior under cyclic loading protocols and the famous earthquake records with different materials such as steel and interconnection equipment by superelastic shape memory alloys have been investigated. Then, the results were compared to demonstrate that such connections are ideal against the seismic behavior and energy dissipation.

Effect of the anionic composition of acidic solutions containing Fe(III) on the protection of low-carbon steel by a triazole inhibitor

The corrosion of low-carbon steel 08PS in 2 М HCl, 2 М H2SO4, and 2 М H3PO4 solutions as well as in their mixtures at t = 20–80°C has been studied. Addition of a mixture of the IFKhAN-92 inhibitor, which is a triazole derivative, with KCNS slows down the corrosion of the low-carbon steel in these media. The presence of Fe(III) in the solutions weakens steel protection by the inhibitor formulation studied. The presence of phosphates in an acid solution decreases the adverse effect of Fe(III) as it binds Fe(III) cations into strong phosphate complexes. This effect is most distinct in H3PO4 and H2SO4 + H3PO4 solutions with high H3PO4 content. A mixture of IFKhAN-92 and KCNS forms a polymolecular inhibitor layer on the steel surface. This layer can efficiently slow down the reduction of Fe(III) phosphate complexes. In steel etching or in cleaning of steel equipment in acidic solutions, where Fe(III) salts are accumulated and accelerate steel corrosion, it is recommended to use solutions of H3PO4 or its mixtures with H2SO4 (at least 50%) inhibited by a formulation of IFKhAN-92 with KCNS.

Cleanability of milk deposits on inner stainless steel tubing surfaces prepared by magnetic abrasive finishing

Milk deposits are a serious technical and economic problem for the dairy industry. The proteins and minerals in milk form deposits on the surfaces of stainless steel equipment. The Magnetic Abrasive Finishing (MAF) process was used to produce highly finished inner surfaces of stainless steel tubes to compare to tubes with conventional inner surfaces. Deposition and cleaning tests were carried out using an experimental loop including the stainless steel tubes with different surface roughness profiles. Data showed that the smoothly finished inner surface (Ra = 0.037 μm) of stainless steel tubes prepared by MAF significantly improved the cleanability of milk residues. The results may indicate that the cleanability of non-protein components of milk residue is affected by surface roughness.

Using Elemental Analysis To Manage Industrial Corrosion

Abstract As industrial infrastructure continues to age, the risk of corrosion-related incidents becomes greater, increasing the need for detailed analysis of residual elements in steel framework and equipment. X-ray fluorescence is seeing greater use due to new smaller, lightweight equipment designs.

(Invited) Corrosion Inhibitor (Decanethiol) for Carbon Steels Exposed to Aqueous CO2

CO2 corrosion mitigation is a challenge in the oil and gas industry. In order to decrease the severity of CO2 corrosion of carbon steel pipelines and equipment, different mitigation practices are recommended. One such strategy is the application of surface active chemical inhibitors. The objective of this study was to evaluate the inhibition effectiveness of decanethiol in a CO2-saturated aqueous electrolyte (1 wt.% NaCl). The inhibition properties of decanethiol were evaluated by electrochemical measurements (linear polarization resistance (LPR) and electrochemical impedance spectroscopy (EIS)) and the steel surface characterized by scanning electron microscopy (SEM). The obtained data show that decanethiol successfully prevents corrosion of carbon steels in a CO2 environment. An inhibition mechanism was also proposed based on adsorption characteristics and film formation. Keywords : CO2 corrosion, decanethiol, carbon steel, EIS, surface film

Corrosion failure analysis in a biodiesel plant using electrical resistance probes

Abstract The search for alternative forms of energy that generate a lower emission of carbon dioxide and pollutants leads to an increase in biodiesel fuel production in Brazil. The corrosion of steel equipment is a major problem in biodiesel fuel plants. The methodology applied in the research includes a survey of operating conditions and failure history as well as collection and analysis of corrosion data obtained in installing AISI 316L electrical resistance probes at strategic points in the process.

Reduction of chloride ions in the diethanol amine cycle and improvement of the natural gas sweetening

This study investigates the effects of a continuous decline in chloride ion concentration in the diethanol amine (DEA) solution of a sweetening natural gas system, including the effects on corrosion of the internal surfaces of carbon steel equipment, and on frequently observed problems resulting from an inefficient amine system for the liquefied petroleum gas plant. In this study, output solution samples of DEA from the regeneration tower were analyzed. It was observed that, the number of chloride anions was increased to 350 mg/L; consequently, the concentration of iron ions were also enhanced up to 14 mg/L. These changes confirmed that the internal corrosion rate of the towers and exchangers increases in contact with DEA solution containing a higher concentration of chloride anions and iron ions. In order to reduce the corrosive properties of the DEA solution within the gas sweetening system, continuous removal of chloride anions was accomplished in an ion exchange system based on a strong anionic resin (4200CL- Utilized in water treatment packages). The results showed a decrease of the chloride and iron ion amounts in the diethanol amine solution, which reduced the internal corrosion rate of carbon steel, consequently decreasing non-routine maintenance. The more these heat stable salts (chlorides) decreased the more stability the unit operation gained. According to this study's findings, the plant improved its process of operations and reduced energy consumption.

Differing factor adjustment costs across industries: Evidence from Japan

This study uses industry data from Japan to examine the joint behavior of investment and hiring. We estimate factor adjustment costs in industries and focus on the industrial differences in such costs. Our analysis reveals that heavy industries, such as steel and transportation equipment, require relatively large adjustment costs. Furthermore, comparing our results with studies that estimate these adjustment costs using US data, we find that the ratio of labor adjustment costs to total adjustment costs is higher in Japan than in the US. Our findings could be very useful in considering the implications of economic policies on factor adjustments.

The Prevalence and Control of Bacillus and Related Spore-Forming Bacteria in the Dairy Industry.

Milk produced in udder cells is sterile but due to its high nutrient content, it can be a good growth substrate for contaminating bacteria. The quality of milk is monitored via somatic cell counts and total bacterial counts, with prescribed regulatory limits to ensure quality and safety. Bacterial contaminants can cause disease, or spoilage of milk and its secondary products. Aerobic spore-forming bacteria, such as those from the genera Sporosarcina, Paenisporosarcina, Brevibacillus, Paenibacillus, Geobacillus and Bacillus, are a particular concern in this regard as they are able to survive industrial pasteurization and form biofilms within pipes and stainless steel equipment. These single or multiple-species biofilms become a reservoir of spoilage microorganisms and a cycle of contamination can be initiated. Indeed, previous studies have highlighted that these microorganisms are highly prevalent in dead ends, corners, cracks, crevices, gaskets, valves and the joints of stainless steel equipment used in the dairy manufacturing plants. Hence, adequate monitoring and control measures are essential to prevent spoilage and ensure consumer safety. Common controlling approaches include specific cleaning-in-place processes, chemical and biological biocides and other novel methods. In this review, we highlight the problems caused by these microorganisms, and discuss issues relating to their prevalence, monitoring thereof and control with respect to the dairy industry.

Effect of Plasma Nitriding Surface Modification on the Adhesion of Food Pathogens to Stainless Steel AISI 316 and AISI 304

Food pathogens like Salmonella spp. and Listeria monocytogenes can attach to surfaces commonly found in food processing environment, increasing the risk of foodborne diseases. Therefore, the use of effective strategies to reduce bacterial adhesion on equipment surfaces is a subject of great interest for food industries. The plasma nitriding treatment has been investigated for surface modification of biomedical materials, aiming to reduce bacterial attachment. However, this technology has not yet used in food equipment surfaces. The objective of this study was to evaluate the effect of plasma nitriding surface modification of stainless steels on the adhesion of S. Enteritidis and L. monocytogenes. Coupons of stainless steel AISI 316 and AISI 304 were treated with plasma nitriding (30 Pa, 100 W), and bacterial adhesion was compared with untreated coupons. Bacterial counts and surface hydrophobicity were analyzed before and after treatment. Results showed that plasma nitriding treatment modified the hydrophobicity of the stainless steel surfaces, and the number of attached cells was reduced when compared to untreated stainless steel coupons. Based on these results, plasma nitriding treatment may be a promising technology, which can be used to hinder bacterial attachment on stainless steel surfaces. Practical Applications The modification of stainless steel surfaces with plasma nitriding can influence on the bacterial adhesion, contributing with food safety. This surface treatment can be used in industrial scale before the manufacture of stainless steel equipment used in food industries. The use of equipment treated with plasma nitriding do not compromise food with chemical or physical residues, however, it should be used as an additional control measure to microbial hazards and do not substitute Good Hygiene Practices.

A Decrease in Corrosion Loss of Steel Wares when Removing Carbonate Scales

Adsorption of EDTA on calcite depending on the EDTA concentration and pH of the solution is investigated. It is established that adsorption enhances when decreasing pH of the solution being rather efficiency in neutral media as well. The adsorption efficiency is weakly acidic media makes it possible to solve a problem of corrosion loss of steel equipment due to lowering the concentration of mineral acid when removing carbonate scales.

Developing the biofacility of the future based on continuous processing and single-use technology

To maintain or strengthen their market position, biopharmaceutical producers have to adapt their production facilities to a drastically changed market environment. Contrary to currently used large scale batch-wise operated production facilities, where stainless steel equipment is widely applied, small scale and flexible production processes are desired. Consequently, the concept of the “biofacility of the future” has been developed, which combines the attributes fast, flexible, small, inexpensive and sustainable. Four design principles build the facility’s basis and are presented within this work: continuous processing, 100% single-use equipment, closed processing and adopting the ballroom concept. However, no publication presents a completely continuously operated platform process for the production of monoclonal antibodies up to now. Therefore, this work establishes the proof of concept regarding continuous antibody manufacturing. A pilot plant for the production of monoclonal antibodies has been built 100% in single-use equipment. It was operated fully continuous and automated in the upstream and the downstream part. The concepts that allow continuously operating the pilot plant are presented within this work, i.e., continuously operated filtration, continuously operated viral inactivation, continuously operated chromatography and a continuously operated formulation. Analytics showed that the produced product was within specification limits of industrial bulk drug substances.

원전의 내환경기기검증 화학환경 및 핵분열생성물 제거능력 평가

원자력발전소는 냉각재상실사고(LOCA)와 같은 과도상태시 pH 조절을 통해 격납건물의 핵분열생성물(요오드) 제거 능력을 유지한다. 이와 더불어 격납건물 내부의 스테인레스강 기기들의 응력부식균열(Stress Corrosion Cracking)을 방지하고 알루미늄 또는 아연 부식에 의한 수소생성을 최소화할 수 있기 때문에 살수 및 집수조냉각수의 화학조건(pH) 조절능력이 요구된다. 현재 원전은 LOCA시 능동형 살수첨가제인 NaOH를 사용하여 격납건물 살수 및 집수조냉각수의 pH를 조절하도록 설계되어있다. 본 논문에서는 LOCA시 집수조냉각수의 pH를 분석하고, 살수화학조건 pH 관련 최신규제요건인 표준심사지침(SRP) 6.5.2에 따라 핵분열생성물제거상수 및 제염계수를 계산하였다. 분석결과, 격납건물집수조 pH는 8.09~9.67로서 설계기준을 만족한다. 그리고 격납건물살수계통에 의한 핵분열생성물 제거상수 및 제염계수는 원전 내환경기기검증을 위한 방사선환경 평가의 입력으로 제공된다. Nuclear Power Plants require the control ability of chemical condition (pH) because pH control during transient accident such as LOCA makes an able the fission product removal capability to be maintained, stress corrosion cracking of stainless steel equipment to be prevented and the production of hydrogen by aluminum and zinc to be minimized. An NPP is designed to control the pH of containment spray and sump coolant using the spray additives 30% NaOH in the event of loss of coolant accident. In this paper, the pH of sump coolant of an NPP during LOCA was analyzed and the fission products removal constant and decontamination factor were calculated according to Standard Review Plan 6.5.2 related to spray chemical conditions of pH. The calculated pH value of recirculation mode using the computer code corresponds to 8.09~9.67, which meets the chemical environment regulation requirements. The fission product removal capability caused by containment spray system is performed to provide input to radiation analysis.

Future proofing biopharmaceutical manufacturing: the industry seeks a leaner version of itself

How detrimental is it for a biopharmaceutical company to be stuck with legacy technologies, watching competitors transition to new, more efficient, and more cost–effective platforms? That question is facing many biopharmaceutical manufacturers as the industry gradually shifts away from the use of traditional stainless steel equipment and moves into greater adoption of newer technologies, such as single-use devices, modular, and continuous processing systems. Future-proofing in bioprocessing today involves adding flexibility into manufacturing strategy. Modular bioprocessing facilities is an example that involves the integration of prefabricated bioprocessing modules or suites in a ‘plug and play’ manner that allow companies to assemble bioprocessing systems using off-the-shelf modules that easily hook up with other modules. The spread of such modular bioprocessing facilities, along with wider penetration of single-use systems for commercial manufacturing, could revolutionize bioprocessing, particularly in emerging markets (where local populations increasingly demand products) and facilitate more global standardization of manufacturing. Although single-use equipment and module bioprocessing involve unique systems, they are being increasingly adopted because they offer advantages over legacy technologies: more adaptability; more efficient capacity utilization; and more portability. In fact, one of the main reasons the industry is looking to increase its use of disposables is for the flexibility of the ‘modular’ approach. This is the direction the industry is moving in – and it’s a far cry from the large, fixed, multi-million-dollar stainless steel systems that have dominated manufacturing. Indeed, late last year when we surveyed the more than 450 global subject matter experts and senior participants who make up our Biotechnology Industry Council [1], single-use applications and adoption emerged as one of the key ‘future vision’ bioprocessing trends. Other key trends involving design strategies pointed to topics such as:

Welding of Stainless Steel - A Heavy Engineering Perspective

Stainless steels are engineering materials capable of meeting a wide range of design criteria. They exhibit excellent corrosion resistance, strength at elevated temperature, toughness at cryogenic temperature and fabrication characteristics, and they are selected for a broad range of consumer, commercial, and industrial applications. In the fabrication of stainless steel products, components, or equipment, manufacturers employ welding as the principal joining method. Stainless steels possess good weldability and a welded joint can provide optimum corrosion resistance, strength, and fabrication economy provided reasonable care is exercised during welding. L&T's Heavy Engineering (HE) has established a reputation for quality products in the global market with its strong engineering capabilities and state-of-the-art manufacturing facilities. It manufactures and supplies various critical equipments like reactors, vessels, heat exchangers and inter-connecting piping to Fertilizer, Refinery, Petrochemical, Chemical, Oil & Gas, Power, Nuclear and allied Strategic sectors. The wide spectrum of equipments mentioned involves fabrication of various grades of Stainless Steel (SS)like Austenitic, Ferritic, Martensitic, Duplex, Super Duplex etc. This paper discusses some of the high productivity welding processes and the techniques being used in manufacturing Stainless Steel vessels at Larsen & Toubro’s Heavy Engineering such as: Narrow groove welding of high thickness SS joints by Submerged Arc Welding(SAW), High deposition SS weld surfacing using Electro Slag Strip Cladding (ESSC), Hotwire GTAW for joining & surfacing of SS, SS Liner welding by GTAW for critical Urea Service applications, Automatic Tube to Tube sheet Welding etc.

Degradation/Damage Modes and their Control Measures for Stainless Steel Components in Chemical Plants

Safe and continuous operation of chemical plants is the most important issue for sustainability of chemical enterprises. The control and prevention of degradation/damage on components used in chemical plants are indispensable for this purpose. Although varied types of material, such as stainless steels, Ni-based alloys and reactive metals, are in use to control these phenomena in plants, various cases of degradation/damage have actually been experienced and the accidents caused by such degradation have occasionally been reported. In order to prevent such uncontrolled degradation, it is thought necessary to predict the likelihood of degradation of materials under actual operating conditions, to use compatible materials, to detect the degradation by inspection in advance and to apply proper countermeasures based on realistic life estimation of the plant concerned. In order to follow these processes properly, extensive accumulation and orderly organization of knowledge about the mechanisms on degradation/damages, characteristics of materials, inspection technics and methods of plant life estimation are thought of vital importance. As stainless steel is the commonly used material in chemical plants, sufficient accumulation of informattion and knowledge about the stainless steel components to be used is considered the most important subject to prevent the degradation/damage in chemical plants. This paper enumerates the characteristics of commonly encountered modes of degradation with stainless steel components in chemical plants and presents some cases of the degradation/damage on stainless steel equipment in plants, together with control measures required to prevent such degradation. The present-day problems of materials engineering relating to the reliability of chemical plants and the countermeasures against degradation/damage are also presented.

Welding and Fabrication of Stainless Steel Equipment for 500MWe Prototype Fast Breeder Reactor

Austenitic stainless steel is the major structural material for the primary and secondary sodium systems (except for the steam generators) for the currently operating and planned fast reactors all over the world. The boundaries of sodium systems of Prototype Fast Breeder Reactor (PFBR) is designed so as to have an extremely low probability of leakage, rapidly propagating failure and gross rupture under the static & dynamic loads expected during various operating conditions.The degradation of material properties (e.g. effect of sodium, temperature and irradiation), transients, residual stresses, flaw size etc. are the important considerations, which shall be taken into account. The principal material of construction for PFBR is austenitic stainless steel of grade 316LN/304LN. The scope of welding and fabrication of PFBR components is too large due to versatile types of systems with varieties of components with complex constructional features. High operating temperature of various systems causing high stresses are to be minimized by designing thin walled structure. Most of the Nuclear Steam Supply System (NSSS) components are thin walled and require manufacturing in separate nuclear clean hall conditions to assure the quality.The welding with stringent tolerances along with high distortion in stainless steels due to high thermal expansion and low thermal conductivity makes the fabrication extremely challenging.The welding standards and acceptance criteria of PFBR equipment is stringent compared to other industrial specification. Manufacture of over dimensional components (diameter greater than 12m and thickness upto 40mm) such as MainVessel, Safety Vessel, Inner Vessel involves die pressing of large size dished end & conical petals. The solution annealing of cold worked petals is a mandatory requirement if strain exceeds 10%. Innovative welding techniques and many trials were conducted on mock up for establishing the process parameters. The forming techniques, bending methods and welding procedures were qualified with stringent non-destructive and destructive examinations and testing before taking up the actual job. Thermal Baffle has two large concentric cylindrical shells, inner and outer shells of about 12.4m diameter and fabrication is a challenging task. PFBR also involves dissimilar joint welding between carbon steel (A48P2) and austenitic stainless steel (316LN) at integration location of roof slab & main vessel. This welding is carried out by combination of Gas Tungsten Arc Welding (GTAW) & Shielded Metal Arc Welding (SMAW) processes using ER 309L & E 309-16 welding consumables with controlled heat input to minimize the dilution of carbon & distortion. The weld between primary pipe & grid plate cannot be accessed for in-service inspection and therefore requires extra-ordinary skilled welders. Space constraints & lack of accessibility makes the welding & inspection challenging. This paper highlights the welding and fabrication aspects of few major, over dimensional and critical equipment of 500MWe Prototype Fast Breeder Reactor. Keywords: Stainless Steel, Main Vessel, Safety Vessel, Inner Vessel, Grid Plate, PFBR, SS welding, distortion.

Thermal degradation of monoethanolamine and its effect on CO2 capture capacity

Amine scrubbing is a proven technology in the oil and gas industries. Its use in coal fired power plants is not fully understood and the likelihood of solvent degradation is high. Decreased absorption efficiency, undesirable by-products and the environmental impact of their disposal are the main consequences. In the present study, samples of monoethanolamine were thermally degraded, at 160°C for between 2 and 8 weeks, and their CO2 removal capacity deterioration was determined. The findings show that thermal degradation at 160°C for 8 weeks reduced monoethanolamine concentration by 95%, but the remaining solvent still retained 22% of its capacity to remove CO2, probably due to the capacity of some of the degradation products to remove CO2. Therefore, the requirement for monoethanolamine make-up in operational amine scrubbing systems may not be quite as serious as initially believed. A 20% higher MEA loss was determined in the samples with 0.37 initial CO2 loading (molCO2/molMEA). 2-Oxazolidone, N-(2-hydroxyethyl)-ethylenediamine and 1-(2-hydroxyethyl)-2-imidazolidinone were identified as the major monoethanolamine degradation products, the latter being indicated as the most stable product with concentrations of up to 17% (v/v). Corrosion (1.95mm/year) of the stainless steel (type 316) equipment, used during the experiments, was also observed.

Оценка влияния дефектов сварных соединений на прочностную надежность стальных сосудов и аппаратов

Оценка влияния дефектов сварных соединений на прочностную надежность стальных сосудов и аппаратов

Power Plant Wastewater Cleanup through Capacitive Deionization

Power plant wastewater is a complex mix of dissolved ionic content resulting from various impurities present in the coal as well as corrosion products from steel equipment. Multifaceted water treatment processes are currently used to lower contaminant concentrations, but stricter regulations will further decrease the allowable discharge limits. To address this issue, the use of a capacitive deionization (CDI) process is shown which can effectively deionize various power plant wastewater and solvent streams. Carbon xerogel electrodes synthesized with a range of pore sizes and a conductive, flexible carbon support enables the capture of both monovalent and divalent species from waste streams. Electrosorption capacities of 2-4 mg NaCl/g of xerogel have been shown with carbon surface areas between 140-240 m2/g.