Remnant Life Assessment and Microstructural Studies on Service Exposed Primary Reformer Tubes of a Catalytic Converter of an Ammonia Plant
-
Krishna Guguloth
,
Jaganathan Swaminathan
Abstract
13.5 year service exposed (SE) catalyst primary reformer tube material made of H39WM micro-paralloy grade used in feritilizer plant was assessed for remaining life. The investigation includes mechanical properties evaluation; microstructural analysis and accelerated stress rupture tests. Failed tube portions showed coarsening primary carbides of Chromium and Niobium along the grain boundaries. Degradation of Niobium carbide (NbC) into Ni-Nb-Si phase and partial conversion this phase back to NbC was observed. Secondary carbides within grains were almost absent. Degradation in tensile strength for a range of temperature from 1123 to 1223 K was also observed but they were within the specified limits. Premature failures within 3–5 years service exposure are more common in reformer tubes. The failure was attributed to localized overheating leading to creep damage. The cast tube material may undergo microstructural changes during service exposure which is the main cause of degradation in strength and hardness changes. Accelerated stress rupture tests were performed in the range of 1173–1248 K on samples machined from 13.5 years at 1191 K and 15.4 MPa exposed reformer steel tubing, did not reveal any degradation of rupture behavior compared to that of the virgin alloy. An additional life of at least 10.6 years is predicted at the operating stress-temperature conditions.
©[2012] by Walter de Gruyter Berlin Boston
Articles in the same Issue
- Masthead
- High Temperature Tensile Properties of Equal Channel Angular Pressed Al-Zn-Mg-Cu Alloy
- Hard Finish Turning Parameters Optimization for Machining of High Temperature Stainless Steel
- High Cycle Fatigue and Cyclic Plastic Deformation Behaviour of High Temperature Oxidation Resistant Titanium Aluminide Coated IMI 834 Alloy at 873 K
- Microstructural and Mechanical Properties of Er2O3-ZrO2 Ceramics with Different Er2O3 Contents
- Synthesis of Different Morphologies of PbS Nanostructures via Hydrothermal Process
- Facile Hydrothermal Synthesis of CoSO4ċH2O Nanoparticles and Barite Microcubes from Novel Precursors
- Hot Corrosion of Fe-Cr Alloys with 75 Na2SO4 + 25 NaCl Coating at 1173 K
- A Simple Method for Synthesis of PbS Nanoparticles Using 2-Mercaptoethanol as the Capping Agent
- Influence of Alloy Grain Size on High Temperature Corrosion Behavior of 2.25 Cr-1 Mo Steel in SO2 + O2 Atmosphere
- Encapsulation of Erbium(III) and Thulium(III) Nanocomplexes Containing 18- and 20-Membered Dioxa Tetraaza Macryclic Ligands Within the Framework of Zeolite
- Calculation of the Raman Linewidths of Lattice Modes Close to the α-β Transition in Quartz
- Production and Characterization of Hydroxyapatite-Zirconia Composites
- Influence of Long-term Aging on Microstructure and Creep Behaviors of FGH95 Nickel-based Superalloy
- Remnant Life Assessment and Microstructural Studies on Service Exposed Primary Reformer Tubes of a Catalytic Converter of an Ammonia Plant
- Preparation and Characterization of Poly Methyl Methacrylate-cadmium Sulfide Nanocomposite
- Oxidation Kinetics of Steels Utilized in the Production of Valves in Automobile Industry
Articles in the same Issue
- Masthead
- High Temperature Tensile Properties of Equal Channel Angular Pressed Al-Zn-Mg-Cu Alloy
- Hard Finish Turning Parameters Optimization for Machining of High Temperature Stainless Steel
- High Cycle Fatigue and Cyclic Plastic Deformation Behaviour of High Temperature Oxidation Resistant Titanium Aluminide Coated IMI 834 Alloy at 873 K
- Microstructural and Mechanical Properties of Er2O3-ZrO2 Ceramics with Different Er2O3 Contents
- Synthesis of Different Morphologies of PbS Nanostructures via Hydrothermal Process
- Facile Hydrothermal Synthesis of CoSO4ċH2O Nanoparticles and Barite Microcubes from Novel Precursors
- Hot Corrosion of Fe-Cr Alloys with 75 Na2SO4 + 25 NaCl Coating at 1173 K
- A Simple Method for Synthesis of PbS Nanoparticles Using 2-Mercaptoethanol as the Capping Agent
- Influence of Alloy Grain Size on High Temperature Corrosion Behavior of 2.25 Cr-1 Mo Steel in SO2 + O2 Atmosphere
- Encapsulation of Erbium(III) and Thulium(III) Nanocomplexes Containing 18- and 20-Membered Dioxa Tetraaza Macryclic Ligands Within the Framework of Zeolite
- Calculation of the Raman Linewidths of Lattice Modes Close to the α-β Transition in Quartz
- Production and Characterization of Hydroxyapatite-Zirconia Composites
- Influence of Long-term Aging on Microstructure and Creep Behaviors of FGH95 Nickel-based Superalloy
- Remnant Life Assessment and Microstructural Studies on Service Exposed Primary Reformer Tubes of a Catalytic Converter of an Ammonia Plant
- Preparation and Characterization of Poly Methyl Methacrylate-cadmium Sulfide Nanocomposite
- Oxidation Kinetics of Steels Utilized in the Production of Valves in Automobile Industry
