Scenario 1 S

No CRACK, Lamellar Tearing

Pipe line project…. There is additional jumper with pipe…. There is an
attachment….. With type Set In & Set On

1 The Inspector report that Lamellar Tearing was occur Lamelar Tearing occur in Set In? or Occur in Set On?
Inspector Reported Lamellar Tearing occur in pipe to pipe butt weld found by
2 Lamellar Tearing not occur in this type of join and Can't found by RT
RT

3 From Vessel drawing…. BOM plate S355xxZ, what NDT requirement base on Lam Check (UT) for thickness > 25 mm (Spec 9.1 Page 17 of 48).
that materials?
4 Lamellar tearing occur in the type join? Pipe to pipe 2G position, Pipe Tee Join single bevel

CRACK, Solidification Crack

CS pipe CE 0.45, U butt join welding with SAW, there is centre line crack
Excessive load, Less restrain, Chemical composition, or SAW not suitable for this join, ada
5 juga jawaban Dilution
Inspector reported centre line crack was occurred, What is the main reason?
6 Solidification Crack occurred because? Sulphur content < 0.015, Sulphur content > 0.15, C-Mn content 1.35% or No effect from
chemical
7 The inspector reported that there is improper preheat before welding
Preheat litle or no significant effect on this type of crack, Preheat is one of the problem
8 In the weld process using SAW and than back gauge than re weld using MMA , Depth to Width ratio > 2:1, Deth to Width ratio < 2:1
any possibility crack happen, why?

HICC
9 Four factor of Hydrogen cracking Hydrogen level, Stress > 0.5 YS, Temperature < 300ᵒC, Susceptible microstructure
10 Four factor of Preheat HI, Hydrogen level/ molecular hydrogen, CEV, Combine material thickness
11 Inspector said PWHT will perform 5 days after welding completed a. PWHT shall be perform after weld completed (Spec 19.4 note page 38 of 48, Note)
b. PWHT shall be perform earlier to eliminate residual stress
c. PWHT shall be perform after weld completed and NDT performed.
12 Temperature < 300ᵒC …….Preventive Post Heat (tidak jelas)

Consumable
13 Copper coating on MAG steel wire melengkung, apa alasannya? Corrosion resistance, Electrical pick up and improve wire feeding.
14 Helix size on MAG wire: To avoid problem with arc wandering
15 E 51 3 B Cover Electrode, 510 N/mm² Yield strength, impact test at -30ᵒC with 47 Joules energy,
Basic electrode
16 Electrode wire on MAG steel wire keluar melengkung, apa alasannya? ada pilihannya karena di buat memang begitu, Harus disupport dengan sesuatu,
Arc Energy and Heat Input
16 Hitung Arc energy for MMA Gampang
17 Hitung parameter yg masuk, Process pakai TIG, thickness 6 mm. Spec
18 Pilih HI yg out of heat input permitted (MAG Process). 1.6 KJ/mm
Hitung dulu Heat Input dengan parameter yg sudah ada, setelah dapat lihat di
WPS parameter itu bisa lari 15% dari value yg ada. Hitung maximum dan
minimumnya

Destructive test
19 Hitung elongation L1= 185, Lo= 160, 25:160= 15.6% 15%
Break di Weld metal 120% of UTS, Break di Parent metal 0.9 of UTS (hitung dan cari), UTS
20 Check hasil tensile test yg out of spec material 480 N/mm² (Max 480 x 1.2 = 576 pilihannya ada 600).
21 Root dan Face bend dilakukan di material 25 mm thickness Side bend should be perform on this thickness material.

Weld Fracture
22 Rough and Torn Ductile, Shear lips, over loaded, Dull and gray, High temperature.
23 Brittle combine with Ductile Flat and torn
24 Suddently Fracture/ yg tiba-tiba Brittle fracture, Speed of sound, Chevron marks, Flat and rough but not torn & Crystalline
appearance
25 Fatique Fracture Smooth profile, Beach mark, Colour contrast, slow propagation
26 Chevron Marks Brittle fracture, Speed of sound, Chevron marks, Flat and rough but not torn & Crystalline
appearance
Residual stress and distortion
27 Material the least residual stress a. HSLA steel b. Low carbon steel c. Medium Carbon steel d. All material same
residual stress
27 Best practice to control distortion on welding Place weld about neutral axis, Reduces number of passes, Reduce weld metal volume,
use balance welding.

Heat Treatment
28 Process PWHT (ada 2 soal beda tipis) Yield fall, Stress fall (during heating), stress remain flat (at lower level) and Yield goes up
(during cooling).
Unrestricted heating rate to 320ᵒC, resticted heating rate to 650ᵒC, short soaking,
29 PWHT sequence on C-Mn steel Steam pipe (Spec 19.3 Page 38 of 48)
Resticted cooling rate to 320ᵒC, Unrestricted cooling rate.

Weld Repair
30 Weld repair inside vessel using TIG argon shielding gas Safety precaution
31 There is a repair by RT (lack of side wall fusion), What you should do? Gauging and check by MT or PT (Spec 10.3 Page 19 of 48).
32 After VT, UT, RT there is defect slack inclusion 29mm, LOF 10mm, Under Cut 2
location 20mm & 30mm with depth 1 mm, what will you do? Check with the acceptance level

WPS and Welder Qualification

33 What kind test shall be carried out for welding Qualification Tee Fillet Weld? Hardness, Macro and Fracture (Spec 17.8 Table 8a. Page 37 of 48).
34 Welding Position if any impact requirement 12.5 mm thickness Vertical up position with Impact energy 40 joules averages Value. Spec 17.12, 17.13 Table
9
35 Welding Position which highest and Lowest Heat Input/ Pernyataan PF (Slowest travel speed) and PE

Specification (Mostly refer to Pressure Vessel drawing and TWI spec).

Materials:
Head : EN 10028-2 P355GH Z, PL 50 mm THK
Shell : EN 10028-2 P355GH Z, PL 50 mm THK
Neck : EN 10028-2 P355GH Z, PL 30 mm THK
Base Plate : 20 mm THK
Web Saddle : 20 mm THK
Saddle Repad : 20 mm THK
Horizontal Vessel with 2 Saddles.

36 Cut hole Nozzel using arc flame Cutting: a. Remind 3 mm and grind. b. Is not allowed (Spec 4.2 Page 10 of 48).
37 On which velocity you should stop MMA weld activity? a. 15 Mph b. 17 Mph c. 30 km/hour d. 45 km/hour (Spec 4.6 Page 12 of 48)
38 Minimum fillet weld size for joint base plate to saddle web? 20 mm (Spec 5.3 Page 12 of 48).
39 Refer to Shell material, what is testing has been carried out as stated Z / Hati2
ada yg bilang ditanya untuk face bevelnya (dia bicara joint W1) a. MPI b. RT c. UT d. STRA (Spec 9.1 Page 17 of 48). Kalau face brarti MPI

40 Join Head to Shell using single Bevel a. 45 deg b. 35 deg (Spec 4.2 Page 10 of 48) 30 +5/ -0 c. 60 deg
41 Advantage of Set On the Nozzel to Shell a. No back gauging required b. Less bevel preparation c. No Lamellar Tearing
42 Long arc welding Lack of shielding, hydrogen level increase
43 Porosity in the SAW process (tak ada jawaban berkaitan dengan flux) Kira - kira CTWD contol out of WPS
44 Destructive testing for Welding Procedures- Joint Web Saddle to Repad Fillet Weld: Hardness, Macro & Fracture (Spec 17.8 Table 8a Page 31 of 48)
45 Destructive testing for Welding Procedures- Joint Neck to Head (Jt. 5) But Weld: Transverse Tensile + Impact + Side Bend + Hardness + Macro (Spec 17.8 Table
8a Page 31 of 48) (Qualified by pipe to pipe).
46 Joint Base Plate to Sadle Web Fillet Weld
47
a. Impact b. Penetrant c. Fracture d. 2 option are correct
Testing perform during welding qualification for joint base plate to saddle web
48 Joint Nozzel to Shell Set In PA position No danger Lamellar Tearing, Easy access to back side or root so full penetration are
easier, beveled in Shell, More weld volume so more distortion

No General 1S
1 Improve Toughness Manganese
2 Improve Hardness Carbon
3 Elongation (L1 - Lo)/Lo x 100%
4 Fillet Fracture Test (Qualification Weld) Hardness + macro, Qualitative test, to check quality of weld, for welder test
Hydrogen >15% ml/100, Stress > 0.5 of Yield Strength, Temperatur < 300ᵒC, Susceptible
5 Factor HICC
microstructure (Martensite) hardness > 400 VPN
6 Sequence of PWHT Heating, short soaking, cooling
7 BS EN 1011 Welding - Recommendation for Welding of Metallic Materials
A documents, which recommends practice or procedure. A documents that recommends
8 Code of practice is, Jawabnya pendek je practice or procedures for the design, manufacture, installation, maintenance, utilisation,
of equipment, structure or products.
9 Dimana Lamellar Tearing terjadi Set On, T Joint, MMA
10 Heat Input Hitung
11 Brittle Rough but not torn, Flat, Crystalline appearance, Chevron mark, fast, low temp.
12 Ductile Rough and Torn, shear lips, Reduction area,
13 STRA (Short transverse reduction area) Z material, > 20% STRA is good quality, unlikely lamellar tearing
14 Quenching, Normalizing & Annealing terjadi di? Upper Critical Point
15 Dip transfer compare to spray transfer which one will be more affected to Dip Transfer lower HI / All position
heat input
16 Hitung UTS Easy lah
17 Bend Test (20 mm) Side Bend Test
18 Distortion Control Technique Balance welding, reduce number of passes, use fast welding process, Use back skip
welding. Joint preparation from single to double.
19 Reduce Welding Time (Single or double?) by Change join design or change welding process (manual to semi auto or to auto)
20 k Factor Loss energy, arc energy efficiency
21 Weaving - Width weld bead High Heat Input, lower toughness
22 Element- Sulphur Solidification Creck
23 Arc length too long increase Hydrogen/ lack of shielding/ Tendency HICC
24 Fatique fracture will be continues with what fracture Commontly ductile fracture
25 Chevron mark usualy present in what fracture Brittle fracture
26 Cyclic load corelation with fatique Load below YS, crack growth
27 For welding TIG what current charateristic Constant current
28 Why austenitic stailess steel not require to pree-heat? Becouse not change during heating and cooling
29 Burmah castrol for what MPI sensitivity test (Flux measurement)
30 Temperatur for UT Testing as per ISO 17640 0ᵒC to 60ᵒC
31 Thickness 12.5 mm, how many probe will used? 3 probe, 0, 60 and 70
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33 CONSENTRATION ON LOWER RESIDUAL STRESS; materials, joint preparations, etc
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Factor that effect Weldability:

Actual chemical composition

Weld joint configuration
Welding process to be used
Properties required from the weldment

Low alloy steel sulit mengontrol hardness di HAZ jadi

lebih tendecy H cracking dari C atau C-Mn

H Cracking in weld metal happen in HSLA and usually V

shape/ Chevron crack

Factor that effect suscetibility of Hot Cracking:

Weld metal has a susceptible chemical composition

A.sulphur max 0.015, if in the mill cert show 0.15% B.Sulphur max 0.015, if in the mill cert show 0.005%
High level of restraint or tensile stresses present in the
weld area