CIP 1 Day 1 and 2 Flashcards
The deterioration of a material, usually a metal, that results from a reaction with its environment
Corrosion
The formation of a thin surface layer of corrosion product can form an effective barrier against further attack that can slow down the rate of corrosion process.
Passivation
For corrosion to occur; certain conditions and elements are essential.
Corrosion Cell
The electrode of an electrochemical cell at which oxidation occurs. Electrons flow away from the anode in the external circuit. Corrosion usually occurs and metal ions enter the solution at the anode.
Anode
The electrode of an electrochemical cell at which reduction is the principal reaction Electrons flow towards the cathode in the external circuit.
Cathode
Connects the anode and the cathode and allows passage of electrons, generated at the anode, to the cathode.
Return Path
Medium that conducts ionic (rather than electronic) current
Electrolyte
The oxide layer formed during hot fabrication or heat treatment of metals. A blue-black layer of iron/iron-oxide; cathodic relative to substrate; Generally removed prior to painting
Mill Scale
A list of materials in order of their corrosion potentials; with the most easily corroded, or most active, at the top and the least active at the bottom.
Galvanic Series
Relatively uniform loss of material over the entire surface and in general thinning of the affected surface.
Generalized Corrosion
Occurs at discrete sites on the metal surfaces. Usually at defects in coating; Changes in contaminants or pollutants, changes in the electrolyte.
Localized Corrosion
Corrosion does not proceed uniformly but primarily occurs at distinct spots where deep pits are formed.
Pitting Corrosion
Occurs on a metal surface that is shielded from full exposure to the environment because of the close proximity of another material that forms a narrow gap between them.
Crevice Corrosion
Substance that, when added to an environment, prevents or decreases the rate of corrosion.
Corrosion Inhibitor
A technique to reduce the corrosion of a metal surface by making the surface the cathode of an electrochemical cell. Uses sacrificial anodes, magnesium, zinc or aluminum, that will corrode in preference to the steel structure they are connected to.
Cathodic Protection
A reduction of the anodic reaction rate of an electrode involved in corrosion
Passivation
What are the elements of a corrosion cell?
Anode, cathode, metallic path and electrolyte
Different concentrations of oxygen on the same metal usually occurs in immersion conditions.
Oxygen Concentration Cell
Increase the rate of corrosion by increasing the efficiency (conductivity) of the electrolyte.
Chemical Salts
Causes very rapid rusting; Airborne salts and chemical pollutants. Humidity and seawater provide the electrolyte.
Chemical/Marine Environment
Highly corrosive environment because of the gases, chemicals and high humidity
Chemical with High Humidity
Gases and chemicals stimulate corrosion even in low humidity
Chemical with Low Humidity
Provides an active electrolyte because of the moisture and the salt particles
Marine with High Humidity
Chemical with High Humidity
Highly corrosive environment because of the gases, chemicals and high humidity
Marine with High Humidity
Provides an active electrolyte because of the moisture and the salt particles
Chemical with Low Humidity
Gases and chemicals stimulate corrosion even in low humidity.
Splash Zone Area
Mid-tide to 12 ft above high tide
Rural Environments
Least corrosive environment due to clean air, few pollutants and low moisture
Least corrosive environment due to clean air, few pollutants and low moisture.
Rural Environments
What occurs at the anode?
Metal ions enter into the solution and corrosion usually occurs at this location, generates the electrons
What is the function of the electrolyte?
To carry the metal ions to the cathode and to complete the electrical path
What is the function of the metallic path?
To carry the electrons connecting the anode and the cathode
5 Factors that affect the rate of corrosion
Oxygen, temperature, chemical salts, humidity and pollutants and acid gases.
Common tools to control corrosion?
Design, inhibitors, material selection, cathodic protection, protective coatings, splash zone systems, alteration of environment.
Mission statement: Undertake simple coating ________ under _________.
Inspection work; direct supervision of a qualified level III inspector
Mission statement: Read and comprehend a _________ ___________.
Coating specification for surface preparation and coating application
Mission statement: Use simple________ ___________.
Inspection equipment
Mission statement: comprehend and use________ _________ __________.
Surface preparation standards (NACE, SSPC, and ISO) to recognize specified surface cleanliness
Mission statement: Recognize inspectors job as __________ of a _________ effort.
Part of a team effort
Mission statement: Recognize importance of_________ meetings.
Pre-job
Mission statement: Recognize need to determine_____________ and ______________
Inspector responsibilities and authority
Priority
- Matches. Number 2.Handaxe. 3. Heavy duty canvas. 4. sleeping bag. 5. Maple syrup. 6. Nylon rope. 7. Snowshoes. 8. Inner Tube. 9. Shaving kit. 10. Flashlight. 11. Rum. 12. Clock. 13. Compass. 14. Book. 15. Water Tablets.
Reference standard inspectors responsibilities are to
Obtain, study, and become familiar with each and every part of the standard and it’s relationship to the project
Some metals like zinc aluminum copper and brass for protective _______ ______ when exposed to the atmosphere
Protective oxides
Corrosion is the _________ of a material usually a_______, because of a________ with its environment
Deterioration, metal, reaction
Four elements of a correction
Anode, cathode, metallic path, electrolyte
The anode __________ in the electrolyte.
Dissolves
The two broad classifications for curing mechanisms are
Non-convertible and convertible
Four types of adhesion
Chemical, mechanical, polar, combo
List to nonconvertible coating types
Vinyl latex
List three convertible coating curing mechanisms
Oxidation, co-reaction, hydrolysis, fusion
List two characteristics of oxidation cure coatings
Cannot withstand an alkaline environment due to the saponification; excessive film build up my stop tearing of the lower portion of the coating film; Unsuitable for merchant service; care bye reaction with atmospheric oxygen
List three coding types that cure by polymerization
Epoxy, polyurethanes, Polyurea, polysoxanes, polyaspartics
Induction time
The amount of time after mixing two parts before applying paint to give the time for reaction
What is the main requirement for hydration coating to cure
Some amount of water to complete the cure
Industrial and marine coatings are commonly referred to as
Aromatic polyurethanes
Oil based coating applied over alkaline surfaces may result in
Saponification
Five formal sections usually contained in a good specification
Scope of the work, terms and definitions, reference standards,safety, surface preparation, coding materials including the coding schedule, sample coatings, workmanship, application, work schedule, repairs and remedial coding work, inspection, documentation
What are two of the inspectors responsibilities as they relate to the specification
To enforce the spirit suffocation, determine what standards and codes apply, safety, and sure the areas to be repaired or clearly identified workmanship application, Work. schedule
Components of a coating added in small amounts to perform a specific function
Additives
Process in which the similar molecules cling together due to attractive forces
Adhesion
A coating that has a high resistance to permeation of liquids and or gases or is applied over previously coated surface to prevent damage to the underlying coding during subsequent handling
Barrier coatings
Nonvolatile portion of the vehicle of a formulated coating material
Binder
A pig with the passivate the metal surface by forming and then tightly adherent film or by reinforcing and plugging the effects of the natural air formed film
Inhibitive pigment
Coatings who’s binders are made from nonliving things, most commonly based on either silicone or
Inorganic coatings
Coatings who’s binders are made from living or once living things
Organic coatings
Find solid particles added during the manufacture of a coating which are substantially in soluble in the vehicle
Pigment
Why is pigment added
To impart color, corrosion control or decorative properties
Coding that uses a metal that is not to steal encroach preferentially
Sacrificial coating
Added to coatings to liquefy the binderand allow for application in a productive manner
Solvents
Type of resin polymerized from acrylic acid, methacrylic acid, esters of these acids or acrylonitrile
Acrylic
Coating Specification tells the contractor ….
What to do and where to do it but does not tell how to do it.
Absolute wording - Contractor
Shall/Shall not
Not absolute - Owner
Should/Should not
Strong Recommendation - either
Should
Optional Wording - either
May
Inspector Responsibility - Coating materials
Only specified materials are used, Ensure proper storage conditions, observe pot life and induction/sweat-in times, Know volume of solids, wet and dry-film thickness and allowable tolerances, dry and recoat times, proper cure time.
Elements of a typical Specification
Workmanship, Application, Work Schedule, Repairs and Remedial work, Inspection and documentation (who it will be sent to)
Inspectors Responsibility - Job Site
Walk-through to become familiar with the surroundings; each item to be coated or left un-coated; Obtain maps or drawings that would be helpful
Inspectors Responsibility - Standards and Codes
To determine all federal, state and local codes that apply to the job; obtain, study and become familiar with each and every part of the standard and its relationship to the project.
Inspectors Responsibility - Safety
OWN SAFETY FIRST; Safety enforcement is NOT my job; Be knowledgeable enough to recognize safety violations, Report all safety violations immediately to the proper personnel, be informed of any hazardous substances associated with the work they perform
Inspectors Responsibility - Pre-job Conference
Study the specification before the meeting, Crystal clear understanding of specification, modifications or waivers and AUTHORITY on the job.
Inspectors Responsibility - Surface Preparation - Standards
Standards: Ensure specified cleanliness standard is used, ensure surface is prepared as specified, verify on the specified materials are used.
Inspectors Responsibility - Surface Preparation - Anchor Profile
Know exactly what anchor pattern tolerances are allowed.
Inspectors Responsibility - Sampling of Coatings
Select samples at random, ensure coatings are thoroughly mixed, proper sample amount, label the sample container as specified (preprinted or know who to send them to directly)…. dry or wet (clarify at pre-job meeting)
Inspectors Responsibility - Workmanship
Have the latest copy of manufacturers instructions, clarify performance expectations at pre-job meeting, and report unacceptable work.
Inspectors Responsibility - Application
Spec with state who gets the reports; Ensure coating is done as specified, know exactly what thickness tolerances are allowed, Report non-compliance to owner.
Inspectors Responsibility - Work Schedule
Understand the work schedule (which item first, etc); Ensure job is done in the manne outlined by the contractor and approved by the owner; inspect at the specified intervals; Prepare and submit the reports as specified. GOOD VISUAL INSPECTION
Inspectors Responsibility - Repair work
Ensure areas to be repair are clearly marked and the coating surface properly prepared (clarify what will be used to mark repairs) Monitor the number of repair coats applied, observe re-coat times and check the WFT and DFT as specified; Document the work
Inspectors Responsibility - Inspection
Perform QC tasks and document, Verify that work complies with Spec, report all non-compliant work and deviations.
