CIP 1 Day 1 Flashcards
Anode
The electrode of a cell at which oxidation occurs. Electrons flow from the anode. Corrosion occurs at the anode.
Cathode
The electrode of a cell at which reduction occurs. Electrons flow toward the cathode.
Cathodic Protection
Technique used to reduce corrosion by making the surface the cathode.
Corrosion
The deterioration of a metal that results from a reaction with its environment.
Corrosion Cell
In order for corrosion to occur, a combination of an anode, cathode, return path, and electrolyte must be present.
Corrosion Inhibitor
A chemical substance that prevents or reduces corrosion.
Crevice Corrosion
Localized corrosion that occurs in an area that is within close proximity to the surface of another material.
Electrolyte
Chemical substance containing ions that migrate in an electric field.
Galvanic Series
Metals arranged according to their corrosion potentials in a given environment.
Generalized Corrosion
Corrosion that is distributed uniformly.
Localized Corrosion
Occurs at discrete sites on the surface.
Mill Scale
The oxide layer formed during fabrication of steel.
Passivation
Reduction of anodic reaction rate in corrosion.
Pitting Corrosion
Localized corrosion confined to small area
Return Path
Metallic pathway connects the anode to the cathode allowing passage of electrons.
General rules of galvanic corrosion
When dissimilar metals are connected, the most active metal corrodes faster while the least active metal corrodes slower.
As the potential difference between the metals increase, the rate of galvanic corrosion increases.
Five factors that affect the rate of corrosion
Oxygen Temperature Chemical salts Humidity Pollutants and Acid Gases
Common tools/methods for corrosion control
Design Inhibitors Material selection Cathodic protection Protective coatings Alteration of the environment
Effects of Corrosion
Safety
Cost
Appearance
Service environments and corrosion
Chemical/marine Chemical with high humidity Marine with high humidity Chemical with low humidity Rural with low humidity
Handling conflict
Avoid it
Smooth things over
Resolve it
Negotiation
working to arrive at a decision that is accepted by everyone involved
Coatings specification
Formal document containing information on a project.
Instrumentation calibration history reports
Contains information on how frequently each instrument is to be calibrated.
Material Inventory Reports
Contain information on inventory of jobsite materials.
Safety Data Sheets
Form containing data of known substances in a particular product.
Quality Assurance
Systematic process that checks if the product or service is meeting specified requirements. Overall.
Quality Control
Procedure to ensure product or service meets the requirements of the customer. Specific
Quality Control Technician
Inspector’s role. Responsible for observing and reporting technical aspects of a coating project and its conformance or deviation from the specification.
How does NACE define the inspector’s role?
Quality control technician who observes and reports technical aspects of coating project. Observe, test, verify, report.
What is the inspector’s responsibility when it comes to safety on a project?
Safety enforcement is not the inspector’s responsibility. Be knowledgeable of safety violations.
Tests that may need to be conducted during surface preparation and coating operations.
Relative humidity and dew point. surface temperature. surface contaminants. proper abrasive media. cleanliness of abrasive. check air compressor. Air supply to blast hose. Blast nozzle for size and wear. Blasted surface for anchor pattern. Viscosity of coating. Application equipment. DFT of each coat. Surface contaminants.
Documentation/reports that may be required to be maintained on a coatings project.
Daily written report. Inspection logbook. Routine report. Notes from weekly progress meetings. Any reports required by client.
Most important characteristics of a good report?
Objective, accurate, detailed.
What is the inspector’s primary responsibility and what should the inspector not do as it pertains to the specification.
The inspector’s primary responsibility is to VERIFY the specification. The inspector does not make changes to the specification for any reason.
What type of information do you find on a Product Data Sheet?
Application methods surface cleanlinesss parameters temperatures curing times.
What type of information do you find on a Safety Data Sheet
Toxicity Health Effects First Aid Reactivity Storage Disposal PPE Spill Handling Procedures
Conduct tests:
Honestly, accurately, openly
Dew point
Temperature at which moisture will begin to form on a steel surface.
Infrared thermometers
Devices that measure temperature using radiation emitted from objects.
Magnetic surface contact thermometer
Most common instrument to determine substrate temperature.
Psychometric chart
Graph of the physical properties of moist air at a constant pressure.
Psychometric tables
Booklet to determine the relative humidity and dew point temperature.
Relative humidity
The ratio of water vapor pressure in a given volume of air and temperature to the amount required to saturate the air at that temperature.
Repeatability
same readings under ambient and target conditions in instrument.
Sling psychrometer
Measures ambient air temperature to calculate dew point and relative humidity.
Wind speed monitor
instrument for deciding if conditions are appropriate for coating.
Identify some defects that can be caused by incorrect temperature applications
Blistering Pin holing Cratering Dry spray Mud cracking
Name some of the effects wind may have on a coating project.
Blow abrasives past the boundaries of the work area.
Cause drift or overspray of sprayed coatings.
Accelerates solvent evaporation.
Formation of dry spray.
What are some of the common errors when using an electronic hygrometer?
Reading taken in direct sunlight.
Instrument was left in place for too long.
Instrument removed before stabilized.
Calibration or equipment malfunction.
Explain the process for use of the sling psychrometer.
Saturate sock with clean water.
Whirl the instrument rapidly for about 40 seconds.
Read the wet bulb temperature.
Repeat process until the temperature stabilizes 3 times.
Once wet bulb is stabilized, record the dry bulb temperature.
Apply coatings to substrate:
At 5 degrees above dew point temperature
Wet bulb depression
Dry bulb temp minus wet bulb temp
Additives
components of a coating added in small amounts to perform a specific function.
Adhesion
process when dissimilar molecules cling together due to attractive forces.
Barrier coatings
coating that has a high resistance to liquids and gases, and is applied over a base coating.
Binder
nonvolatile portion of coating
Inhibitive pigment
pigment that passivates the metal surface by forming a film or by plugging defects.
Inorganic coatings
binders are made from non-living things, zinc or silicone.
Organic coatings
binders made from once living things.
Pigment
particles that impart color, corrosion control, or decorative properties.
Sacrificial coatings
coatings that use an anodic metal to steel and corrodes preferentially.
Solvents
liquefies the binder to allow for application.
List 3 desirable properties of a coating.
Chemical resistance. Water resistance. Ease of application. Adhesion to substrate. Cohesive strength. Flexibility and elongation. Impact resistance. Abrasion resistance. Temperature resistance. Dielectric strength.
The 2 broad classifications of a coating are:
Organic coating
Inorganic coating
What are 2 primary components of a liquid applied coating?
Pigment
Resin/Binder
Solvent
Vehicle
Describe 3 methods by which coating provides corrosion control.
Barrier - impedes ingress of oxygen, water, soluble salts
Inhibitive - slows down reaction occuring on substrate.
Sacrificial - anodic metal that corrodes preferentially.
What are 3 different ways a coating can adhere to the surface?
Chemical
Mechanical
Polar
Coating composition
Pigment
Resin/binder
Solvent
Vehicle
