basic - op - syllabus
Post on 16-Apr-2015
8 Views
Preview:
TRANSCRIPT
BASICS EXAMINATION OF ISNT LEVEL III
Dr.Oruganti Prabhakar
Nanyang Technological University
Singapore
March 28, 2001
Contents
1 Subject General Knowledge 9
1.1 Technology of NDT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
1.1.1 De�nitions and methodology of applying NDT . . . . . . . . . . . . . 9
1.1.2 Speci�c and distinctive characteristics of these methods . . . . . . . . 9
1.1.3 Areas of NDT applications . . . . . . . . . . . . . . . . . . . . . . . . 9
1.1.4 Quality control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
1.1.5 Maintenance Defectology . . . . . . . . . . . . . . . . . . . . . . . . . 9
1.1.6 Evaluation of properties . . . . . . . . . . . . . . . . . . . . . . . . . . 9
1.1.7 Material Failures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
1.1.8 Purpose for Use of NDT . . . . . . . . . . . . . . . . . . . . . . . . . . 9
1.1.9 NDT IN FRACTURE CONTROL . . . . . . . . . . . . . . . . . . . . 9
2 FUNDAMENTALS OF MATERIALS TECHNOLOGY 11
2.1 PROPERTIES OF MATERIALS . . . . . . . . . . . . . . . . . . . . . . . . . 11
2.1.1 Strength and elastic properties . . . . . . . . . . . . . . . . . . . . . . 11
2.1.2 Physical properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
2.1.3 Material Properties testing . . . . . . . . . . . . . . . . . . . . . . . . 11
2.2 ORIGIN OF DISCONTINUITIES AND FAILURE MODES . . . . . . . . . . 11
2.2.1 Inherent discontinuities . . . . . . . . . . . . . . . . . . . . . . . . . . 11
2.2.2 Process-induced discontinuities . . . . . . . . . . . . . . . . . . . . . . 11
2.2.3 Service-induced discontinuities . . . . . . . . . . . . . . . . . . . . . . 11
2.2.4 Failures in metallic materials . . . . . . . . . . . . . . . . . . . . . . . 11
2.2.5 Failures in nonmetallic materials . . . . . . . . . . . . . . . . . . . . . 11
2.3 STATISTICAL NATUREOFDETECTINGANDCHARACTERIZINGDIS-
CONTINUITIES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
3 PROPERTIES OF MATERIALS INTRODUCTION 13
3.1 CLASSES OF PROPERTIES . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
3.2 SIGNIFICANCE OF PROPERTIES OF DESIGN . . . . . . . . . . . . . . . 13
3.3 LOADING SYSTEMS AND MATERIAL FAILURE . . . . . . . . . . . . . . 13
3.3.1 Loading systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
3.4 TESTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
3.4.1 The Tensile Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
3.4.2 Compression Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
3.4.3 Transverse Rupture Testing . . . . . . . . . . . . . . . . . . . . . . . . 14
3.4.4 Shear Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
3.4.5 Fatigue Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
3.4.6 Creep Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
3.4.7 Notched Bar Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
1
2 CONTENTS
3.4.8 Bend Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
3.4.9 Hardness Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
3.5 Factor of safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
4 FUNDAMENTALS OF FABRICATION AND PRODUCT TECHNOL-
OGY 17
4.1 RAW MATERIAL PROCESSING . . . . . . . . . . . . . . . . . . . . . . . . 17
4.2 METAL PROCESSING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
4.2.1 Primary metals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
5 THE NATURE OF MATERIALS AND SOLID STATE CHANGES IN
METALS 19
5.1 THE EFFECT OF ENERGY ON THE ATOM . . . . . . . . . . . . . . . . . 19
5.2 METALLIC STRUCTURE . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
5.3 SOLIDIFICATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
5.3.1 Grain Size . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
5.4 SOLID STATE CHANGES IN METALS . . . . . . . . . . . . . . . . . . . . . 19
5.4.1 Work hardening . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
5.4.2 Plastic Deformation . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
5.4.3 Cold Work . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
5.5 RECRYSTALLIZATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
5.5.1 Recovery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
5.5.2 Recrystallization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
5.5.3 Grain Growth . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
5.6 AGE HARDENING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
5.7 ALLOTROPIC CHANGES . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
5.8 HEAT TREATMENT OF STEEL . . . . . . . . . . . . . . . . . . . . . . . . 20
5.8.1 Approximate Equilibrium Heat-Treatment Processes . . . . . . . . . . 20
5.8.2 Austenitization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
5.8.3 Annealing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
5.8.4 Normalizing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
5.8.5 Spheroidizing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
5.8.6 Hardening of Steel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
5.8.7 Tempering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
5.9 CASE HARDENING OF STEELS . . . . . . . . . . . . . . . . . . . . . . . . 20
5.9.1 Carburizing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
5.9.2 Flame Hardening . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
6 FERROUS METALS 21
6.1 CHOOSING METALS AND ALLOYS . . . . . . . . . . . . . . . . . . . . . . 21
6.1.1 Ferrous Raw Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
6.2 CAST IRONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
6.3 STEEL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
6.3.1 Wrought Iron . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
6.3.2 Steel Making . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
6.3.3 Plain Carbon Steel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
6.3.4 Alloy Steels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
7 NONFERROUS METALS 23
7.1 MATERIAL IDENTIFICATION SYSTEMS . . . . . . . . . . . . . . . . . . . 23
CONTENTS 3
8 CASTING 25
8.1 Green sand molded . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
8.2 METAL MOLDS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
8.3 INVESTMENT MOULDING . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
8.4 HEAT TREATMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
8.5 THE PROCESS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
8.6 SOLIDIFICATION OF METALS . . . . . . . . . . . . . . . . . . . . . . . . . 25
8.6.1 SOLIDIFICATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
8.7 POURING AND FEEDING CASTING . . . . . . . . . . . . . . . . . . . . . 25
8.7.1 Casting Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
8.7.2 Pouring the Gating Systems . . . . . . . . . . . . . . . . . . . . . . . . 25
8.7.3 Risers Chill . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
9 FOUNDRY TECHNOLOGY 27
9.1 SAND MOLDING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
9.1.1 Green Sand . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
9.1.2 Dry Sand Molds. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
9.1.3 Floor and Pit Models . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
9.1.4 shell Molds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
9.1.5 METAL MOLD AND SPECIAL PROCESSES . . . . . . . . . . . . . 28
9.1.6 Die Casting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
9.1.7 Investment Casting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
9.1.8 Plaster Mold Casting . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
9.1.9 Centrifugal Casting . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
9.1.10 Continuous Casting . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
9.2 MELTING EQUIPMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
9.2.1 Cupola . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
9.2.2 Crucible . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
9.2.3 Pot Furnances . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
9.2.4 Reverberatory Furnances . . . . . . . . . . . . . . . . . . . . . . . . . 28
9.2.5 Electric Arc Furnances . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
9.2.6 Induction Furnances . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
9.3 FOUNDARY MECHANIZATION . . . . . . . . . . . . . . . . . . . . . . . . 28
4 CONTENTS
List of Figures
5
6 LIST OF FIGURES
List of Tables
3.1 Some typical modulus of elasticity of materials . . . . . . . . . . . . . . . . . 14
3.2 Moh's Hardness Values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
7
8 LIST OF TABLES
Chapter 1
Subject General Knowledge
1.1 Technology of NDT
1.1.1 De�nitions and methodology of applying NDT
1.1.2 Speci�c and distinctive characteristics of these methods
1.1.3 Areas of NDT applications
1.1.4 Quality control
1.1.5 Maintenance Defectology
1.1.6 Evaluation of properties
1.1.7 Material Failures
1.1.8 Purpose for Use of NDT
1.1.9 NDT IN FRACTURE CONTROL
9
10 CHAPTER 1. SUBJECT GENERAL KNOWLEDGE
Chapter 2
FUNDAMENTALS OF
MATERIALS TECHNOLOGY
2.1 PROPERTIES OF MATERIALS
2.1.1 Strength and elastic properties
2.1.2 Physical properties
2.1.3 Material Properties testing
2.2 ORIGIN OF DISCONTINUITIES AND FAILURE
MODES
2.2.1 Inherent discontinuities
2.2.2 Process-induced discontinuities
2.2.3 Service-induced discontinuities
2.2.4 Failures in metallic materials
2.2.5 Failures in nonmetallic materials
2.3 STATISTICAL NATURE OF DETECTING AND
CHARACTERIZING DISCONTINUITIES
11
12 CHAPTER 2. FUNDAMENTALS OF MATERIALS TECHNOLOGY
Chapter 3
PROPERTIES OF
MATERIALS
INTRODUCTION
Properties of materials is understood based on the two models: 1. Chemical bonds. 2. Hard
Ball Model. In the ball model the spherical atoms occupy the �xed locations in a crystal
structure. The arrangement of atoms in di�erent planes or cross sections will determine the
mechanical behaviour of materials. In the case of face centred cubic structure the (111) plane
is the close packed plane. It is easy to shear this plane along (111) and not perpendicular.
3.1 CLASSES OF PROPERTIES
3.2 SIGNIFICANCE OF PROPERTIES OF DESIGN
3.3 LOADING SYSTEMS ANDMATERIAL FAILURE
3.3.1 Loading systems
3.4 TESTING
3.4.1 The Tensile Test
The tensile test yields the mechanical properties of a material tested in tension. The tensile
specimens have to be as per some standard. They have the following features: Gauge Length
A certain portion in the main specimen (pl see Figure) is marked as gauge length. This is
used to calculate the percen elongation. It should be borne in mind that the shorter the
gauge length the higher the value of the percent elongation determined.
A-B : Elastic Range B = Elastic Limit: Above this point plastic deformation occurs. C
= Yiled point D-E = Work hardening region. E = Ultimate tensile strength. F = Fracture
strength.
Modulus of elasticity of all plastics is low compared to most metals. Drawn Nylon �la-
ments hasve a tensile strength of 50000 psi which is actually greater than some low strength
steels. Nylon is crystalline. It is used as insulators. It is light in weight, has easily colorabil-
ity and used in �ber reinforced plastics. Materials with Poorly de�ned Yield Point
13
14 CHAPTER 3. PROPERTIES OF MATERIALS INTRODUCTION
Al alloys 10 X 106 psi
Cu alloys 14 to 19 X 106psi
Gray Cast Iron 12 to 19 X 106psi
Steel 28 to 30106psi
Cemented carbide 50 X106psi
Table 3.1: Some typical modulus of elasticity of materials
Modulus of Elasticity
It is also known as Young's Modulus and is represted as E. This is the slope of elastic or the
initial part of the stress - strain curve . Factors that increase the yield strength of materials
at room temperature
Features of the microstructure that prevent the movement of dislocations like : Grain bound-
ary ii) Precipitates iii) alloying additions will increase the strength. At elevated temperatures
the grains start sliding one over the other and hence large grains are preferable. Precipitates
and alloying additions also improve the high temperature strength.
Ductility
PercentageElongation =(Lf ) � (Lo)
(Lo)X100 (3.1)
Resilience and Toughness
Resilience is the area under the stress-strain curve upto the elastic limit from zero load. It
represents the energy that is recoverable.
Toughness
This is the total area under the stress- strain curve starting from load upto fracture. This
value represnts the ability of the material to absorb energy without fracture.
True Stress-True Strain
When the tensile test is carried out the specimen is constantly deforming and the cross
secional area is constantly decreasing. True stress is calculated based on the actual area
of the specimen during the progress of the test. In a similar way the the strain calculated
based on the actual length of the specimen during test is known as True Strain.
3.4.2 Compression Testing
Certain materials like are stronger in compression than in tension. For example cast iron
has a compression strength that is twice its tensile strength. The compression test is carried
out much the same way as the tensile testing.
3.4.3 Transverse Rupture Testing
This test is usually employed for brittle materials the tensile testing is not very useful. So
for brittle materials like concrete this test is used.
(Sr) =3PL
2b(d2)(3.2)
3.4. TESTING 15
Mineral Moh's Indentation
Hardness Number Hardness,kg/mm2
Talc 1 23
Gypsum 2 30
Calcite 3 100
Fluorite 4 160
Apatite 5 400
Orthoclase 6 600
Quartz 7 810
Topaz 8 1200
Corundum 9 1860
Diamond 10 7800
Table 3.2: Moh's Hardness Values
3.4.4 Shear Testing
This test is usually carried out for bolts and rivets.
� =P
2A(3.3)
3.4.5 Fatigue Testing
In fatigue testing the loading is cyclic. A mojority of industrial failures are caused by fatigue
(about 90I stage: Cracks are initiated. II stage: The crack grows during cyclic loading. The
crack surface formed during this stage appears smooth and polised. III stage: The area of
cross section bearing the load is constantly reducing and ata certain stage the cross sectional
area remaining connected is so much reduced the stree developed exceeds the yield stress
and sudden brittle fracture occurs. The fractured surface developed during this stage shows
a well de�ned grain structure.
3.4.6 Creep Testing
3.4.7 Notched Bar Testing
3.4.8 Bend Testing
3.4.9 Hardness Testing
Hardness is a measure of the ability of a material to resist penetration of the near surface
material. Hardness is proportional to material properties like strength. It is di�cult to
convert from one value to another. Moh's test : Moh's scale of hardness varies from 1 to
10. Diamond is 10 and corundum is 9, Talc is 1.
Hardness tests: 1. File test. 2. Brinell test
A steel ball is impressed (10 mm in diameter) is impressed on the material whose hardness
is to be determined. BHN = Load in kg/ Area of impression in mm2. This test gives
consistent results. Modern micro processor based equipment are self loading. Thin material
can not be tested by this method. Rockwell Test This is also an impression test. It has
10 kg as minor load and 60, 100 or 150 kg as the major loads. Di�erential depth between
the minor and the major loads is then directly read by a dial gauge as a Rockwell hardness
number.
16 CHAPTER 3. PROPERTIES OF MATERIALS INTRODUCTION
3.5 Factor of safety
Chapter 4
FUNDAMENTALS OF
FABRICATION AND
PRODUCT TECHNOLOGY
4.1 RAW MATERIAL PROCESSING
4.2 METAL PROCESSING
4.2.1 Primary metals
Metal ingot production
Wrought primary metals
17
18CHAPTER 4. FUNDAMENTALS OF FABRICATION AND PRODUCTTECHNOLOGY
Chapter 5
THE NATURE OF
MATERIALS AND SOLID
STATE CHANGES IN
METALS
5.1 THE EFFECT OF ENERGY ON THE ATOM
5.2 METALLIC STRUCTURE
Microstructure is the appearance of the polished specimen under the microscope.
5.3 SOLIDIFICATION
5.3.1 Grain Size
5.4 SOLID STATE CHANGES IN METALS
5.4.1 Work hardening
The strength of metal is increased by plastic ow and the elastic limit is raised.
5.4.2 Plastic Deformation
This includes slip, twinning etc. Cold work makes the metal(which is strain hardening
by nature) stronger and harder. In most metals dislocation processes are accompanied by
discrete releases of mechanical energy called stress waves.
19
20CHAPTER 5. THE NATUREOFMATERIALS AND SOLID STATE CHANGES IN METALS
5.4.3 Cold Work
5.5 RECRYSTALLIZATION
5.5.1 Recovery
5.5.2 Recrystallization
Cold worked metal has strained grains. A heat treatment can produce new and unstrained
grains. This is called recrystallization. Higher the cold work it is easier to recrystallize the
metal.
5.5.3 Grain Growth
5.6 AGE HARDENING
5.7 ALLOTROPIC CHANGES
5.8 HEAT TREATMENT OF STEEL
5.8.1 Approximate Equilibrium Heat-Treatment Processes
5.8.2 Austenitization
5.8.3 Annealing
5.8.4 Normalizing
5.8.5 Spheroidizing
5.8.6 Hardening of Steel
5.8.7 Tempering
5.9 CASE HARDENING OF STEELS
5.9.1 Carburizing
5.9.2 Flame Hardening
Chapter 6
FERROUS METALS
6.1 CHOOSING METALS AND ALLOYS
6.1.1 Ferrous Raw Materials
6.2 CAST IRONS
6.3 STEEL
6.3.1 Wrought Iron
6.3.2 Steel Making
6.3.3 Plain Carbon Steel
6.3.4 Alloy Steels
Low Alloy Structural Steels
Low Alloy AISI Steels
Stainless Steels
Tools and Die Steels
Cast Steels
21
22 CHAPTER 6. FERROUS METALS
Chapter 7
NONFERROUS METALS
7.1 MATERIAL IDENTIFICATION SYSTEMS
23
24 CHAPTER 7. NONFERROUS METALS
Chapter 8
CASTING
8.1 Green sand molded
8.2 METAL MOLDS
8.3 INVESTMENT MOULDING
8.4 HEAT TREATMENT
8.5 THE PROCESS
8.6 SOLIDIFICATION OF METALS
8.6.1 SOLIDIFICATION
subsectionShrinkage
8.7 POURING AND FEEDING CASTING
8.7.1 Casting Design
8.7.2 Pouring the Gating Systems
8.7.3 Risers Chill
25
26 CHAPTER 8. CASTING
27
28 CHAPTER 9. FOUNDRY TECHNOLOGY
Chapter 9
FOUNDRY TECHNOLOGY
9.1 SAND MOLDING
9.1.1 Green Sand
Patterns
Flasks
Sand Compaction
Cores
Green Sand Advantages and Limitations
9.1.2 Dry Sand Molds.
9.1.3 Floor and Pit Models
9.1.4 shell Molds
9.1.5 METAL MOLD AND SPECIAL PROCESSES
Permanent Mold Casting
9.1.6 Die Casting
9.1.7 Investment Casting
9.1.8 Plaster Mold Casting
9.1.9 Centrifugal Casting
9.1.10 Continuous Casting
9.2 MELTING EQUIPMENT
9.2.1 Cupola
9.2.2 Crucible
9.2.3 Pot Furnances
9.2.4 Reverberatory Furnances
9.2.5 Electric Arc Furnances
9.2.6 Induction Furnances
top related