Corrosion and Materials Technology in Urea Plants: 5-Day Specialized Training Course

Course Overview

This intensive 5-day corrosion and materials technology training provides specialized knowledge for managing corrosion challenges in urea manufacturing facilities. Designed for materials engineers, corrosion specialists, maintenance professionals, and plant engineers responsible for equipment reliability.

Target Audience: Materials engineers, corrosion specialists, integrity engineers, maintenance managers, metallurgists, inspection specialists, and technical professionals in urea facilities.

Course Objectives:

• Understand corrosion mechanisms in urea environments

• Master material selection for urea equipment

• Implement corrosion prevention strategies

• Apply inspection and monitoring techniques

• Develop integrity management programs

Day 1: Corrosion Fundamentals in Urea Environment

Morning Session: Urea Process and Corrosive Environments

Understanding Corrosion Challenges

Foundation of corrosion in urea plants:

Urea Process Overview:

• High-pressure synthesis (140-160 bar, 180-200°C)

• Medium and low-pressure recovery sections

• Vacuum concentration systems

• Finishing: prilling and granulation

• Process fluids: ammonia, CO₂, urea, carbamate solutions

Corrosive Environment Characteristics:

• Ammonium carbamate corrosivity: highly aggressive

• Temperature and pressure effects

• pH variations throughout process

• Oxygen content critical role

• Impurities: chlorides, sulfates, cyanides

• Velocity effects and erosion-corrosion

Afternoon Session: Corrosion Mechanisms

Types of Corrosion

Understanding corrosion mechanisms:

General and Localized Corrosion:

• Uniform attack and corrosion rates

• Pitting corrosion: initiation and propagation

• Crevice corrosion in flanges

• Galvanic corrosion between dissimilar metals

• Deposit-induced corrosion

Stress Corrosion Cracking (SCC):

• Chloride SCC in stainless steels: most critical concern

• Carbonate SCC mechanisms

• Susceptible materials and conditions

• Crack morphology and detection

• Threshold stress and temperature sensitivity

Other Mechanisms:

• Intergranular corrosion and sensitization

• Grain boundary chromium depletion

• Erosion-corrosion in high-velocity areas

• Corrosion fatigue in cyclic loading

• Hydrogen embrittlement considerations

Day 2: Materials Selection and Specifications

Morning Session: High-Pressure Section Materials

Synthesis Section Materials

Mastering material selection for critical equipment:

Stainless Steel Grades:

• AISI 316L (1.4404): baseline material

• AISI 316Ti and 321 (stabilized grades)

• Duplex stainless steels: 2205, 2507

• Super austenitic: 904L, AL-6XN

• Specialty alloys: 25-22-2 (Sanicro 28)

• Safurex (high nitrogen austenitic)

Equipment-Specific Materials:

• Urea reactor: 25-22-2, Safurex, 316L Ti-stabilized

• HP carbamate condenser: titanium, zirconium

• HP stripper: 25-22-2, duplex grades

• HP scrubber: 316L, 25-22-2

• Pumps and valves: duplex or super austenitic

Titanium and Zirconium:

• Unalloyed titanium: Grade 1, Grade 2

• Excellent corrosion resistance, lightweight

• Carbamate condenser tubes: primary application

• Zirconium 702/705 for extreme conditions

• Cost considerations and selective use

Afternoon Session: Recovery and Finishing Materials

Downstream Materials

Understanding materials for less severe environments:

Recovery Section:

• MP decomposer: 316L, duplex stainless steels

• LP decomposer: 316L adequate

• Hydrolysis reactor: carbon steel with cladding

• Heat exchangers: 316L tubes

• Process condensate handling: 316L or duplex

Concentration and Finishing:

• Evaporators: 316L minimum

• Vacuum system: 316L

• Prilling tower: carbon steel with coatings

• Granulators: carbon steel, stainless internals

• Product handling: carbon steel

Alternative Materials:

• Nickel-based alloys: Inconel, Hastelloy

• Composite materials and linings

• Polymer linings and coatings

• Material testing and qualification protocols

Day 3: Corrosion Prevention and Mitigation

Morning Session: Passivation and Inhibition

Active Prevention Strategies

Implementing corrosion prevention:

Passivation Procedures:

• Air passivation process: most common method

• Oxygen injection rates (0.5-3% by volume)

• Ammonia presence requirements

• Temperature and pressure conditions

• Pre-commissioning and periodic re-passivation

• Passivation effectiveness monitoring

Corrosion Inhibition:

• Oxygen as corrosion inhibitor: mechanism

• Ammonia excess for pH control

• Proprietary chemical inhibitors

• Neutralizing amines in condensate

• Inhibitor injection and dosing

Process Control:

• Maintaining optimal NH₃:CO₂ ratio

• Temperature and pressure stability

• Minimizing air ingress

• Chloride control (<2 ppm critical)

• Water quality management

Afternoon Session: Design and Operational Practices

Corrosion-Resistant Design

Applying design principles:

Design Considerations:

• Proper material selection per ISO 15613

• Avoiding dissimilar metal contact

• Crevice elimination in design

• Proper drainage and dead-leg elimination

• Stress concentration minimization

• Weld design and inspection access

Welding Practices:

• Qualified welding procedures (WPS/PQR)

• Low heat input techniques

• Post-weld heat treatment (PWHT) requirements

• HAZ sensitization prevention

• Weld overlay and cladding techniques

Operational Best Practices:

• Controlled startup and shutdown procedures

• Equipment idle time management

• Cleaning and decontamination protocols

• Layup procedures for maintenance

• Nitrogen blanketing during outages

• Water washing procedures and requirements

Day 4: Inspection and Monitoring Techniques

Morning Session: Non-Destructive Examination

NDT Methods

Mastering inspection techniques:

Ultrasonic Testing (UT):

• Thickness measurement programs

• Corrosion mapping and data management

• Advanced UT: PAUT, TOFD

• Remaining life assessment

Visual Inspection:

• External and internal techniques

• Borescope and videoscope applications

• Corrosion morphology identification

• Documentation and photography

Other NDT Methods:

• Magnetic particle testing (MT): surface cracks

• Liquid penetrant testing (PT)

• Radiographic testing (RT): weld defects

• Eddy current: tube inspection

• Acoustic emission: real-time monitoring

Destructive Testing:

• Metallographic examination

• Boat sample analysis

• Corrosion coupon programs

• Intergranular corrosion testing: ASTM A262

Afternoon Session: Corrosion Monitoring

Real-Time Monitoring

Implementing continuous monitoring:

Monitoring Techniques:

• Electrical resistance (ER) probes

• Linear polarization resistance (LPR)

• Corrosion potential monitoring

• Hydrogen probes for SCC risk

• Online thickness monitoring

• Ultrasonic monitoring badges

Process Monitoring:

• Oxygen content analyzers

• pH and conductivity measurements

• Chloride and contaminant analyzers

• Data integration and analysis

Inspection Planning:

• Risk-based inspection (RBI) methodology

• API 580/581 application

• Damage mechanism identification

• Inspection frequency optimization

• Critical equipment prioritization

• Documentation and database management

Day 5: Failure Analysis and Advanced Topics

Morning Session: Failure Investigation

Root Cause Analysis

Expertise in failure investigation:

Failure Analysis Process:

• Incident documentation and evidence collection

• Visual examination and photography

• Laboratory analysis: metallography, SEM

• Mechanical testing of failed components

• Root cause determination

• Corrective action development

Common Failure Modes:

• SCC in HP equipment: case studies

• Pitting failures in stainless steel

• Erosion-corrosion in high-velocity areas

• Weld-related failures: HAZ attack

• Carbamate condenser tube failures

• Pump and valve corrosion failures

Real-World Case Studies:

• Reactor corrosion incidents

• Stripper and condenser failures

• Catastrophic versus gradual failures

• Lessons learned and improvements

• Cost impact analysis

Afternoon Session: Advanced Topics and Future Trends

Emerging Technologies

Exploring innovations:

Advanced Materials:

• Next-generation stainless steels

• Nano-structured materials

• Cost-effective alternatives

• Performance in aggressive environments

Coating Technologies:

• High-performance polymer coatings

• Glass-lined equipment

• Thermal spray coatings

• Coating inspection and quality control

Corrosion Modeling:

• CFD for flow-induced corrosion

• Corrosion prediction models

• Machine learning for failure prediction

• Digital twin applications

Industry Standards:

• ISO 15613: Urea plant materials

• NACE standards for corrosion control

• API and ASME codes

• Emerging regulations

Sustainability and Green Urea:

• Materials for green ammonia feedstock

• Hydrogen compatibility

• Carbon capture integration impacts

• Extended equipment life strategies

• Material recycling and circular economy

Integrity Management:

• Asset integrity management systems

• Corrosion management strategy

• Key performance indicators (KPIs)

• Benchmarking and continuous improvement

Course Deliverables

Participants Receive:

• Comprehensive corrosion and materials manual

• Material selection guidelines

• Inspection procedure templates

• Corrosion monitoring framework

• Case study compilation

• Standards reference guide

• Professional certificate of completion

• Online technical resources access

Interactive Learning:

• Metallographic sample examination

• NDT equipment demonstrations

• Failure analysis workshops

• Material selection exercises

• Group case discussions

Why This Training Is Essential

Key Benefits:

• Prevent catastrophic equipment failures

• Optimize material selection and costs

• Extend equipment life significantly

• Reduce unplanned shutdowns

• Enhance safety and environmental performance

• Build organizational expertise

ROI:

• Reduced equipment replacement costs

• Minimized production losses

• Optimized inspection spending

• Extended turnaround intervals

• Improved plant reliability