TECHNIKON PRETORIA

FACULTY OF ENGINEERING AND THE BUILT ENVIRONMENT

DEPARTMENT OF CHEMICAL & METALLURGICAL ENGINEERING

NAME OF COURSE

CRS 301T (Corrosion III)

QUALIFICATION & SAQA IDCOURSE CODE

Diploma in Engineering MetallurgyCRS301A

COMPILED BY Dr DJ Delport (2013)

ORGANISATIONAL COMPONENT CONTENTS:

41.Welcome

42.LABORATORY Staff

42.1Contact Details

42.2Staff availability

53. Requirements, resources and recommended material.

53.1Requirements for the course

3.1.2Recommended resources...................................................................................................5 64. Code of conduct

64.1 Attendance

64.2 Laboratory, Hearlth & Safety Rules And Regulations

74.3 Responsibilities of students

85. Assessment

85.1Assessment methods and criteria

85.2Assessment rules

95.3 Marking system

105.4 predicate/Year mark

105.5 Moderation

105.6 Promotion requirements

11PRACTICAL

11Keywords

Introduction............................................................................................................................................11

Terms, Concepts and Questions needed to know before starting.........................................................1112Purpose of the experiment

12Outcomes

12Student Preparation

12Safety aspects

13Experimental Procedure

Experimental setup.................................................................................................................................13

Variations (Differences from each Group).............................................................................................1414During exposure

14Cleaning after completion

14Data interpretation

14Expected outcomes.....................

14References

15Report

SECTIONAORGANISATIONAL COMPONENT

1.WelcomeWelcome to laboratory session of Corrosion III. This part of the course provides continuity to represent advanced knowledge in the field of Corrosion Engineering and is offered via experimental work, problem-based work or project-based work over ten weeks. The course is structured in such a way as to master theoretical concepts and principles and various practical skills to complement the major courses in the qualification. We trust you will enjoy the course, and find it interesting and informative. 2.LABORATORY Staff2.1Contact DetailsNAMECAMPUSROOM NOTEL NO

E-MAILCONSULTATION TIMESACADEMIC FUNCTION

Dr. Dawid DelportMainB3-731delportd@tut.ac.za8:30 to 12:00Section Head

Lerato TshabalalaMainB2-152KgomariLC@tut.ac.za8:30 to 16:00Lab Technologist

2.2Staff availabilityIf, after attending class and making every effort from your side to master content, you still have problems with understanding key concepts or principles or their application, lecturers are available for consultation.

The general rules regarding consultation and/or mentorship. No unauthorized entry into the lab will be allowed outside practical times and consultation times. Please adhere to consultation times for each lecturer, technologist or mentor involved with the course. 3. Requirements, resources and recommended material.3.1Requirements for the course3.1.1Prescribed resourcesThe following tables indicate what literature and other resources are essential for successful completion of this course. You are strongly advised to acquire all the prescribed resources. Please note that access to computers operating Excel is imperative.PRESCRIBED RESOURCES

CATEGORYDESCRIPTIONWHERE TO FINDCOSTLEVY

CALCULATOR

COMPUTERLibrary ERC

SOFTWAREMS Excel

MS Word

3.1.2 Recommended resourcesThe following recommend resources will enhance your understanding and knowledge in this course, and you are encouraged to use the following additional resources.RECOMMENDED RESOURCES

CATEGORYAUTHORNAMEPUBLISHERISBN NO

BOOKMars G. FonatanaCorrosion Engineering, 3rd EditionMcGraw Hill, Singapore

BOOKDenny A JonesPrincipals and Prevention of Corrosion, 2nd EditionPearson Education, Prentice Hall

RECOMMENDED ELECTRONIC MATERIAL & WEBSITES

WEBSITESwww.sciencedirect.com

4. Code of conductPlease take note of the following regulations. These regulations are in addition to the standard rules and regulations as determined by the TUT. Please familiarise yourself with the TUT rules and regulations as set out in the student diaries received on registration.4.1 AttendanceAttendance of all practical sessions is of primary importance. It is the learners responsibility to sign the register each week. A minimum attendance of 80% is mandatory for the practical. If the group attendance is below that of the required 80% no marks can be allocated to the total practical mark. Marks will be deducted from group evaluations when group members are not present.4.2 Laboratory, Hearlth & Safety Rules And RegulationsLaboratory work can be extremely dangerous. All though every effort has been made to eliminate the use of explosive, highly toxic, and carcinogenic substances from the experiments you will perform, there is a certain unavoidable hazard associated with the use of a variety of chemicals and glassware. You are expected to learn and adhere to the following general safety guidelines to ensure a safe laboratory environment for yourself and your fellow students.

Students will not be allowed to do practicals if they arent wearing protective overcoats and any other relevant safety equipment. Basic laboratory safety rules will be adhered to at all times while in the laboratory.

It is the responsibility of all persons using the laboratory to report immediately any unsafe act or condition by any person to the Lecturer or Technician.

A safety kit is available from the laboratory technician in the case of an emergency. In the event of a hazardous incident or accident in the laboratory, report the incident to the lecturer and the laboratory technician in charge.

After the incident or accident, the group involved will compile a formal report to explain the situation and suggest prevention measure for the incident or accident. This will be handed over to the laboratory technician within 24 hour of the incident or accident.

If a piece of equipment is defective, it must be reported immediately to the lecture or technician in charge or any staff member present in the laboratory. 4.3 Responsibilities of students

Registration: All students should ensure that they are allocated to groups for the practical lessons. A registration list from the registrar is used to compile the last at the end of registration period.

Preparation: Students are expected to come to all practicals prepared thus it is essential that students research certain aspects before entering the laboratory. Before any experiment is carried out, students are expected to participate in risk assessment drill to establish the safe working procedures to control the hazards, and the risks which could arise from the planned practical work. The risk assessment document attached in the appendices identifies a set of hazard categories which are relevant to the practicals. Please make a declaration on completion of the risk assessment and ensure that the mentor or supervisor involved signs the assessments. Records would be kept by the Technician.

SECTIONBLEARNING COMPONENT

5.1AssessmentAssessment methods and criteriaAssessment of this laboratory course will include experimental work, problem-based work, Project-based works and quizzes, as indicated in the schedule under paragraph 2. The purpose of assessment is to determine whether you have achieved the learning outcomes. The various assessment methods therefore will focus on criteria that will enable the lecturer(s) to determine whether you have achieved the learning outcomes and mastered the required skills. The assessment criteria relevant to each learning outcome are detailed in paragraph 2.5.2Assessment rulesThe general rules of TUT regarding assessment apply. You are advised to familiarise yourself with these rules, as they are applied stringently. All reports shall be submitted typed in Times New Roman, 12pt, 1.5 line-spacing and justified and all headings in the same font and bold. No hand written reports will be marked. Reports shall be submitted after seven days. Reports submitted after 12:00 on the seventh day will be allocated as late arrival and a minimum of 5% will be lost from the final mark. Reports later than a day will lose 10% of the final mark, 2 days late will lose 20% of the final mark and reports submitted later than 3 days will not be accepted. Assessment is based on:

Probe construction

Attendance

Report Context

Report Layout

Calculations

5.3 Marking system The marks will be allocated, particularly with respect to experimental work, problem-based work, project-based work and assignments. Laboratory experiments marks from each experiment will be credited according the marking scale shown in the table below.GUIDELINESMark %

ATTENDANCE

Attendance: - 10% for group member not existing-10

Experimental setup 40

General Presentation20

Correct Material Used10

Functionality10

REPORT50

General Impression: Neatness and Correct format 5

Abstract: Briefly description of the work4

Introduction: Places the work in context 5

Literature Survey: Used sufficient relevant sources and acknowledges. 15

Experimental Procedure6

Results & Discussions: Precision, accuracy and use of statistical methods. Logical Outlay with problems stated and solved clearly10

Conclusions & References: Scientific & Justifiable Format and a minimum of five references should be used5

Total (%)100

Probe design and attendance are regarded as group effort and thus the group will obtain the same mark, reports will be individual work.5.4 EXPErimental markThe experiment mark will be calculated as part of the final mark as indicated in the subject matrix. This contributes 30 percent to the final mark. If you have queries about your mark, you must immediately consult your course lecturer (contact details are given above), before final day of continues evaluation marks report. After the cutoff date, no marks can be changed.5.5 Moderation Moderation of the practicals will be conducted by the preselected moderator of the subject.5.6 Promotion requirementsThe pass mark required a 50%. SECTIONCPRACTICAL GUIDELINES

PRACTICAL

THE CORROSIVE EFFECTS OF AN EXPOSED METAL OBJECT TO SALT AQUEOUS SOLUTION KeywordsCorrosion, Copper, Aluminum, Brass, Bronze, Rate of corrosion Introduction

Corrosion is what happens to metals when they are exposed to water and oxygen in the environment. When iron or steel corrodes, the iron forms reddish brown colored oxides and hydroxides: what we commonly refer to as "rust."

Rusting of iron is an electrochemical process. The iron atoms lose electrons (the chemical process of oxidation), which break down water into oxygen and hydroxide ions (the chemical process of reduction). The hydroxide ions react with the oxidized iron and the dissolved oxygen in the water to form iron oxide.

Iron oxide is permeable to water and oxygen, so the chemical reaction can continue beneath the surface layer. For other metals, such as copper and aluminum, an oxidized layer on the surface actually protects the metal underneath from further corrosion.

In this project, you will measure the corrosion rate of different metals when exposed to salt water.Terms, Concepts and Questions needed to know before starting

To do this project, you should do background information study up that will enables you to understand the following terms and concepts: electrochemistry, oxidation, reduction rust, corrosion, copper, iron, steel, aluminum, zinc, brass and bronze.

Purpose of the experimentThe aim of this experiment is to introduce the students to the topic of corrosion in general, specifically helping them to understand:

1. Which metal would be the most corrosion-resistant at its environment?

2. Group the metals from the least corrosive to the most corrosive.

3. Determine/calculate the corrosion rate of each of the metals at the experimental environment?

Also

At what conditions corrosion will occur

How corrosion happens

The chemistry behind corrosion

The rate of corrosion of different metals at the selected environmentOutcomesBy the end of this experiment the student will be well enough equipped with the practical knowledge of the basic principles of corrosion as well as a better understanding into the:

elements of a corrosion experiment

application of the rate of corrosion of different metals and alloys usage of the Eh/pH diagramsStudent PreparationStudents are required to:

Understand the basic principles of corrosion

Do preliminary theoretical background studies in the aim of guiding them to make certain observations and deduce conclusions

Setup of their own experimental apparatus which will be used during the experiment and verify that the correct criteria has been met.

Safety aspectsUpon entering the lab the following safety precautions must be in place.

Regarding PPE:

wear a laboratory coat

wear closed shoes

If Sulphuric or other acids is used. Sulphuric acid is corrosive and irritant to the skin, if working with sulphuric acid please ensure that latex gloves and safety glasses are worn

Always abide by the basic rules of the laboratory, and posses a safety orientated attitude. Be on the lookout for safety hazards and always report unsafe conditions and incidents. Every student is responsible for his own safety and that of the other people in the lab.

Experimental Procedure

Material and EquipmentTo do this experiment you will need the following materials and equipment:

1. Four flat round samples consisting out of the following metals, (brass, bronze, mild steel and aluminum).

2. 1 Beaker (500ml).

3. 1 Pen

4. Salt (NaCl)

5. Water

6. Fish line

7. Grad wrap (plastic wrap)

8. Camera (optional).

experimental SetupDo background research so that you are knowledgeable about the terms, concepts, and questions. Fill the beaker with de-ionised water.

Dissolve the predetermined salt (NaCl) in the water.

Fasten each metal sample with fish line through the small hole on the metal sample to the pen.

Hang the pen on the over the edges of the beaker so that the metal samples is immersed in the water but does not touching each other and does not lie down on the bottom also.

Observe/ analyse (take data) of the samples at least once a day for 2 months.

Take photos at the start and at the end of the experiment.

Variations (differences from each group)

Different concentrations of salt water. Does more salt in the water speed up the oxidation reaction? Why or why not?

What happens if there is very little oxygen in the water? Use boiled water (to remove oxygen), and fill the jar all the way to the top with water (pour carefully so that you don't re-oxygenate the water). Attach the wires to the bottom of the jar lid (e.g., with hot glue), and close the jar lid tightly.

What happens if the pH of the water is changed? You could make the water acidic by adding vinegar or basic by adding baking soda.

Have you seen pictures of the Titanic or other underwater shipwrecks? What happens to artifacts like iron cannonballs when they are brought to the surface from a shipwreck? Design an experiment to see what happens to metal wires immersed in fresh or salt water and then exposed to air. During exposure

Students are required to check in regularly the mass changes and log the values for use to determine the corrosion rates. Also observe the changes inside their beakers and to make notice of them. Cleaning after COMPLETIONAll equipment used for this practical must be cleaned after completion of experiment. Students must also report to the Laboratory Technologist for inspection of workplace.

Data interpretation

Students should be able to determine the rate of corrosion using standard formulas as well as to express the rate of corrosion in terms of mass loss and gain against time. Students should consult handbooks for the usage of correct formulas in order to calculate the rate of corrosion for the metals given.Questions

1. Why are roofing nails zinc-coated?

2. What chemical reaction occurs when iron rusts?References Mars G Fontana,1987, Corrosion Engineering,3rd Edition, McGraw Hill, Singapore

Denny A Jones, 1996, Principals and Prevention of Corrosion, 2nd Edition, Pearson Education, Prentice Hall

ReportThe basic structure of a technical report applies:

Title Page

Abstract One short paragraph (approx 150 words) which gives the aim of the experiment, how the experiment was carried out, what was the most important findings and conclusions

Introduction A broader statement regarding the aim of the experiment, the way in which it will be carried out, what the limitations of the experiment are (i.e. until where will we go about the experiment), what is expected to occur. This section should not be more than one page.

Background Preferably done before commencement of the practical, the background gives relevant information about previous work done and what the findings and pitfalls, the applicability in industry, the basic knowledge towards the practical for the common man to understand. Limited to three pages.

Experimental setup Explains the equipment, the setup and the manner of the proceedings as accurately as possible as has been done so that the experiment can be repeated in future, to obtain the same results

Results and Discussion The information retrieved from the raw data captured example graphs and figures only. Discussion is focused on what was observed, what can be seen in graphs and figures, and how it relates towards the theory as discussed previously.

Conclusions and Recommendations Here the findings are summarized and upon the summarized findings given, recommendations are drawn up. Limited to one page

References Please follow the Harvard technique with inline referencing in the context of the background and full referencing in the References section after the report, if unclear visit published reports from the ERC using the science direct web site. Or follow this link: http://www.lib.uct.ac.za/infolit/bibharvard.htm Appendix Used to show calculations and all raw data in the form of tables

Additional remarks. Please attach a feedback form with your report for continual improvement of the practical (provided)

Arial 12pt with 1.5 line spacing and 0pt spacing before and after paragraph for the context

Arial 14pt with 1.5 line spacing and 0pt spacing before and after paragraph, and UPPERCASE, Bold and Underline for Main Headings (Ex. 1. HEADING 1 Arial 12 with 1.5 line spacing and 0pt spacing before and after paragraph and Bold for subheadings (ex. 1.1 Heading 1.1)

Arial 12 pt with 1.5 line spacing and 0pt spacing before and after paragraph for further headings

Indent subsections to line up with their relevant headings, form a ladder effect

Use justify for context

Graphs and tables are centered and placed in line with text, Tables named at the top, graphs and figures at the bottom; refer to the graph/figure ore table numbers during discussions.

Be careful when using color to compare two situations in graphs, rather change the format to dotted and stippled lines.

Title page shall be provided.

STUDENT LABORATORY GUIDE

Practical 1

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