Ra.c Qualification and reliability testing

General Information section 3.0

In a Preliminary Welding Procedure Specification (pWPS), the General Information section provides the basic identification and reference details of the welding procedure. This section allows welders, inspectors, and engineers to easily identify the procedure being used.

📋 pWPS General Information (Typical Items):

✅Base Metals - are the actual workpieces (plates, pipes, structural members, etc.) that will be welded. The WPS clearly identifies them to ensure proper welding parameters and quality.

📌 Key Information Included in pWPS for Base Metals:

1. Material Specification
Example: ASTM A36, API 5L, ASME SA516
Defines the standard and chemical/mechanical properties

2. Material Grouping
Based on codes like ASME Section IX (P-Number)
Example:
P-No. 1 → Carbon steel
P-No. 8 → Stainless steel

3. Thickness Range
Minimum and maximum thickness qualified
Example: 6 mm to 25 mm

4. Material Type
Plate, pipe, tubing, etc.

✅Filler Metals - are materials (wire, rod, electrode) that melt during welding and fuse with the base metal to create a strong joint.

📌 Key Information Included in pWPS for Filler Metals:

1. Specification (Code Standard)
Example:
AWS A5.1 (Carbon steel electrodes)
AWS A5.18 (GMAW wires)

2. Classification
Identifies strength and usability
Examples:
E6013 (SMAW)
E7018 (Low hydrogen electrode)
ER70S-6 (GMAW/GTAW wire)

3. F-Number (ASME Section IX)
Group filler metals with similar usability
Example:
F-No. 3 → E6013
F-No. 4 → E7018

4. A-Number
Based on weld metal chemical composition

5. Diameter / Size
Example: 2.6 mm, 3.2 mm

6. Consumable Type
Covered electrode, solid wire, flux-cored wire, etc.

✅Shielding - refers to the method used to protect the weld pool from contamination (like oxygen, nitrogen, and moisture in the air) during welding.

📌 Types of Shielding in pWPS:

1. Shielding Gas (External Gas)
Used in processes like GMAW (MIG) and GTAW (TIG)
Common gases:
Argon (Ar) → Clean weld, used for TIG and aluminum
Carbon Dioxide (CO₂) → Deep pe*******on, cheaper
Argon + CO₂ mix → Balanced performance
Example (pWPS Entry):
Gas: Argon + 20% CO₂
Flow rate: 15–20 L/min

2. Flux Shielding
Used in SMAW (Stick) and FCAW (Flux-Cored)
Shielding comes from flux coating or core
Produces protective gas and slag during welding
Example:
E6013, E7018 electrodes (SMAW)
FCAW wire with flux core

3. Combination Shielding
Used in FCAW-G
Uses both flux + external gas

📌 Key Parameters in WPS (Shielding Section):

1. Type of shielding (Gas / Flux / Both)
Gas composition (%)
Flow rate (L/min or CFH)
Backing gas (if applicable, e.g., argon for root pass)

✅Technique - refers to the specific way the welder performs the weld to ensure consistency, quality, and compliance with the qualified procedure (PQR).

📌 Key Technique Variables in pWPS:

1. Stringer vs Weave Bead
Stringer bead → Straight pass (narrow, less heat input)
Weave bead → Side-to-side motion (wider bead, more coverage)

2. Electrode Manipulation
Angle (work angle & travel angle)
Motion (zigzag, circular, whipping, etc.)

3. Number of Passes / Layers
Single-pass or multi-pass welding
Includes:
Root pass
Fill passes
Cap pass

4. Cleaning Between Passes
Methods:
Chipping
Wire brushing
Grinding

5. Direction of Welding
Forehand (push) or Backhand (drag) technique

6. Arc Control - Affects pe*******on and stability
Arc length (short, medium, long)

✅Post Weld Heat Treatment—a controlled heating and cooling process applied after welding to improve the properties of the welded joint by:
Reducing residual stresses
Improving toughness
Preventing cracking (especially in thick or high-strength steels)

📌 Key PWHT Variables in WPS:

1. Temperature Range
Example: 580°C – 650°C (for carbon steel)

2. Holding Time (Soaking Time)
Depends on thickness
Typical: 1 hour per inch thickness

3. Heating Rate
Controlled to avoid thermal shock
Example: 100–200°C/hr

4. Cooling Rate
Slow and controlled (often inside furnace)

5. Method
Furnace heating
Local heating (electric resistance pads)

General Information section 2.0

In a Preliminary Welding Procedure Specification (pWPS), the General Information section provides the basic identification and reference details of the welding procedure. This section allows welders, inspectors, and engineers to easily identify the procedure being used.

📋 pWPS General Information (Typical Items):

✅Joint Design - Refers to how the parts to be welded are prepared and arranged before welding. It is a critical element because it directly affects weld quality, strength, pe*******on, and overall performance.

🔧 Key Elements of Joint Design in pWPS

1. Type of Joint - Specifies the configuration of the materials:
Butt Joint – two plates aligned in the same plane
Fillet Joint – typically in T, lap, or corner joints

2. Joint Preparation (Edge Preparation) - Describes how the edges are shaped before welding:
Square edge
Single V-groove
Double V-groove
Single bevel
Double bevel
U-groove / J-groove

3. Groove Angle - The included angle between the prepared edges (e.g., 60° for a V-groove). Affects pe*******on and electrode accessibility.

4. Root Gap (Root Opening) - The distance between two members at the root:
Ensures proper pe*******on
Typical range: 2–4 mm (depends on WPS)

5. Root Face (Land) - The small flat portion at the root of the groove:
Prevents burn-through
Usually around 1–3 mm

6. Backing (if applicable) - Material placed at the root to support molten weld metal:
Permanent backing (left in place)
Temporary backing (removed after welding)

7. Method - refers to how the joint area is cleaned before, during, and after welding to prevent contamination and ensure weld quality.

✅Position - defines the orientation of the weld and the workpiece during welding. It is a key variable because it affects technique, heat control, and weld quality.

1. Welding Progression - refers to the direction in which the weld is deposited, especially in vertical welding positions.

🔧 Types of Welding Progression:
1. Vertical Up (Upward Progression) - Welding starts from the bottom, going upward.

Slower travel speed
Provides deeper pe*******on and stronger weld

✔️ Used for:

Thick materials
Structural and pressure applications

2. Vertical Down (Downward Progression) - Welding starts from the top, going downward.

Faster travel speed
Shallower pe*******on

✔️ Used for:

Thin materials
Sheet metal or non-critical welds

✅Electrical Characteristics - define the electrical settings used during welding. These parameters control the heat generated, arc stability, pe*******on, and overall weld quality.

⚡ Key Electrical Characteristics in pWPS
1. Transfer Mode - refers to the way molten metal transfers from the electrode/wire to the weld pool, mainly in GMAW (MIG/MAG) and FCAW processes.

🔧 Types of Metal Transfer Modes:

🔧 Short Circuit Transfer (Short Arc)
Wire touches the weld pool, causing a short circuit
Low heat input

✔️ Used for:

Thin materials
All positions (including vertical & overhead)

✔️ Advantages:

Less distortion
Good control

🔧 Globular Transfer
Large droplets fall into the weld pool due to gravity
Medium heat input

❌ Disadvantages:

More spatter
Less stable arc

✔️ Usually avoided in high-quality welding

🔧 Spray Transfer
Fine droplets sprayed across the arc
High heat input

✔️ Used for:

Thick materials
Flat and horizontal positions only

✔️ Advantages:

Smooth weld
Deep pe*******on
Minimal spatter

🔧 Pulsed Spray Transfer
Combination of spray transfer with controlled pulses
Lower average heat than pure spray

✔️ Used for:

Thinner materials than spray
Out-of-position welding possible

✔️ Advantages:

Good pe*******on
Low spatter
Better control

2. Current - refers to the amount of electrical flow (amperage) used during welding. It is one of the most critical parameters because it directly controls heat input, pe*******on, and weld quality.

⚡ Types of Welding Current

⚡ Direct Current (DC)

Flows in one direction
Produces a stable arc

Types of DC:
DCEN (Direct Current Electrode Negative)
More heat on the base metal
Deeper pe*******on

DCEP (Direct Current Electrode Positive)
More heat on the electrode
Better arc stability and cleaning action

⚡ Alternating Current (AC)

Current alternates direction
Balanced heat between the electrode and the base metal

✔️ Common for:

SMAW
GTAW (especially aluminum)

🔧 Effect of Current on Welding

🔼 High Current
Deeper pe*******on
Wider weld bead

Risk of:
Burn-through
Undercut
Excessive spatter

🔽 Low Current
Shallow pe*******on
Narrow weld bead

Risk of:
Lack of fusion
Poor arc stability
Slag inclusion

✅Power Source - refers to the type of welding machine and its output characteristics used to supply electrical energy for welding. It is essential because it affects arc stability, metal transfer, and overall weld quality.

⚡ Types of Welding Power Source

1. Constant Current (CC) Power Source
Maintains steady current (amperage) even if arc length changes
Voltage varies automatically

✔️ Commonly used for:
SMAW (Stick welding)
GTAW (TIG welding)

✔️ Advantage:
Stable arc control for manual welding

2. Constant Voltage (CV) Power Source
Maintains constant voltage
Current varies depending on arc length

✔️ Commonly used for:
GMAW (MIG/MAG)
FCAW

✔️ Advantage:
Self-regulating arc (good for wire feed processes)

✅Tungsten Electrode - essential variable in a pWPS because they determine arc stability, current capacity, and suitability for material and welding process.

🔧 Types of Tungsten Electrodes - Tungsten electrodes are classified based on their alloying elements:

1. Pure Tungsten (Green)
99.5% tungsten
Used for AC welding (aluminum)
Stable arc but lower current capacity

2. Thoriated Tungsten (Red)
Contains thorium oxide
Excellent arc stability and easy starting

✔️ Common for:
DC welding (steel, stainless steel)

⚠️ Note: Slightly radioactive (handle properly)

3. Ceriated Tungsten (Gray)
Good for low current applications
Easy arc starting

✔️ Used for:
Thin materials
DC welding

4. Lanthanated Tungsten (Blue/Gold)
Very versatile
Works for both AC and DC

✔️ Good arc stability and long life

5. Zirconiated Tungsten (White)
Best for AC welding
Resists contamination

✔️ Ideal for aluminum and magnesium

📏 Electrode Size (Diameter)

Specified in pWPS depending on current:
1.6 mm
2.4 mm
3.2 mm

✔️ Larger diameter = higher current capacity

🔥 Electrode Preparation

Tip Shape:
Pointed → DC welding (steel, stainless)
Rounded/Balled → AC welding (aluminum)

Looking for:

10 STRUCTURAL FABRICATORS

Location: Biñan City Laguna
Rate: 750/day +OT
Accommodation: YES
PPE : YES

With pre employment requirements is a plus.

Preferably with at least 1 year of relevant experience. Need experienced structural fabricator. Must know how to read and execute engineering drawings

send your CV at [email protected]