intro

Question 1

3 types of steel frames

Answer 1

1) Moment Resisting frame
2) Concentrically braced frame
3) Eccentrically braced frame

Question 2

Moment Resisting frame facts

Answer 2

beams and connections yield first. then columns yield

Question 3

Concentrically braced frame facts

Answer 3

Braces yield first then columns

Question 4

Eccentrically braced frame facts

Answer 4

active link yields first then columns

Question 5

Stage 1 Steel Production: Production of iron

Answer 5

iron ore and co2 at 1600’C

reduction reaction gives pig iron

Question 6

Stage 2 Steel Production: Manufacturing o and co2 behavior

Answer 6

Oxygen pushed to steel to remove co2

O removed adding aluminum & silicon

Question 7

Stage 2 Steel Production: Manufacturing

Answer 7

molten steel rolled into shape

Question 8

Controlled rolling

Answer 8

reduces grain size ∴ increase toughness, ductility and thickness

Question 9

Ingot cast vs continuous cast

Answer 9

ingot: large cast into large ingots heated and rolled into shape
continuos: cast and rolled into NEAR final shape

Question 10

Manufacture & supply of steel sections: Rolling of plate or section

Answer 10

Mech properties depend on rolling direction

increase rolling > increase yield > tensile strength, no change in elastic modulus.

Question 11

Manufacture & supply of steel sections: Hot rolled section

Answer 11

continuous cast and control roll.

webs stronger than flange because web extra rolled

Question 12

Manufacture & supply of steel sections: Welded sections

Answer 12

welding of hot plate

increase weld section range, reduce hot rolled section range ∴ reduce manufacture cost

Question 13

3 closed cross sections

Answer 13

SHS- Structural hollow steel / square hollow steel

CHS - Circular hollow steel

RHS- Rectangular hollow steel

Question 14

2 principal ELEMENTS of steel

Answer 14

iron & carbon

Question 15

Structural steel made of

Answer 15

0.15% C structural steel is 80% ferrite & 20% pearlite.

Question 16

Ferrite

Answer 16

soft
high ductility
low yield stress

Question 17

Austenite

Answer 17

high temp form of ferrite

Question 18

Martensite

Answer 18

hard
low ductility
high yield stress

Question 19

Effect of increasing in carbon content or rapid cooling from very high temperatures

Answer 19

increase in yield stress

low ductility

Question 20

Role of additions of iron on carbon

Answer 20

+/-
locks dislocations
increase yield stress & tensile strength
reduce ductility

Question 21

Role of additions of iron on vanadium

Answer 21

+

increase yield stress & tensile stress

Question 22

Role of additions of iron on Manganese

Answer 22

+
de oxidiser
remove inclusion
increase ductility

Question 23

Role of additions of iron on sulphur

Answer 23

-

strain aging

Question 24

Role of additions of iron on phosphorus

Answer 24

-

lowers ductility

Question 25

Role of additions of iron on nickel

Answer 25

+/- increase low temp toughness hardens with cold working

Question 26

Role of additions of iron on Hydrogen

Answer 26

- | promotes cracking

Question 27

Role of additions of iron on chromium and molybdenum

Answer 27

+ | increase resistance to corrosion

Question 28

Role of additions of iron on boron

Answer 28

+ | increase strength and toughness

Question 29

behaviour of steel upto fy (yield stress)

Answer 29

elastic

Question 30

behaviour of steel after fy (yield stress)

Answer 30

plastic | yield plateau and strain hardening

Question 31

which grain size is the best and why?

Answer 31

small because of large fracture toughness

Question 32

what is grain size influenced by

Answer 32

alloy additions | thermal and medical treatment

Question 33

why do hot rolled sections distort

Answer 33

when they cool they distort due to differential cool of webs and flanges