Welding Eng Lab Guides.pdf

MEM661 APPLIED WELDING ENGINEERING LAB GUIDELINE

Experiment 1

Title: Obtaining chemical composition using Arc Spark Spectrometer 1. Describe the machine “Arc Spark Spectrometer” 2. What theoretical concept used to identify the elements and the percentages composition contents in the metal matrix? 3. Prepare specimen for arc spark spectrometer test to identify the elements and respective composition accurately. Weld padding (WM)

Base metal

Grind/machine flat for spectrometer test Grind/machine flat for Spectrometer test

4. On carbon steel I. Obtain the composition of BM II. Obtain the composition on WM III. Calculate the Carbon Equivalent (CE) of Base Metal and give meaning. IV. Compare the composition on Weld Metal (WM) with the composition found on Base Metal (BM) and give meaning.

Experiment 2

Title: Effect of Welding Parameters on Weld Penetration

1. Cut, polish, etch, observe, and redraw the macrostructure of the weld bead i.e. WM & HAZ. 2. Measure the depth of weld penetration. 3. Analyze the Macrograph. 4. Discuss the findings. 5. Conclude the experiment.

Experiment 3

Title: Measurement of hardness values

Instruction to students: 1. Cut, polish, etch, observe, and redraw the macrostructure of the weld bead i.e. WM & HAZ. 2. Measure the depth of weld penetration due to changes in welding process both is GMAW & FCAW. 3. Measure the hardness on WM, HAZ and BM using Vickers method at points shown below.

B H W H B M A M A M Z Z 4. Analyze and make comparison in hardness. 5. Discuss the findings. 6. Conclude the experiment.

Experiment 4

Title: Destructive Tests - Bend Test to evaluate quality on Butt Weld.

Weld face

Weld root

Face Band Test (FBT)

Ground flush

Ground flush

40mm

Weld Face

FBT

Root Band Test (RBT) Weld Root

RBT

Experiment 5

Title: Destructive Test – Tensile Strength Test to evaluate quality of weld for Butt Welded Joint 1. Get sample of standard such as ASTM or BS to be used as reference to prepare specimen for Tensile Strength Test.

R

W

R D

B

G

C D

A

A

L = Length of Specimen 2. Configure the test specimen above in detail as according to the selected applicable standard. W = Weld width, D = Reduced section, A = Straight portion, R = Radius, L = Length of specimen (to suit machine), B = Width of specimen (to suit machine), C = Traverse length of weld, G = Gauge Length, T = Thickness of plate 3. Calculate the cross-sectional area at reduced section. 4. Do tensile test and record the yield stress value and UTS value. 5. Observe & record the location of fracture either on WM or BM 6. Obtain from relevant sources the value of yield stress (σ yield ) and UTS of base metal. 7. Calculate/record the % of elongation. 8. Give the meaning of the values obtained in [4] and the observation in [5] to comment on the quality of weld produced as referred to a selected standard for acceptance.