welding inspection and metallurgy. objectives become familiar with definitions and welding...

Welding Inspection and MetallurgyWelding Inspection and Metallurgy

Objectives

• Become familiar with definitions and welding inspection terminology

• Understand the tasks and processes required to perform welding inspections.

- Tasks Prior to Welding.- Tasks during Welding Operations- Tasks Upon Completion of Welding- Non-conformances and Defects- NDE Examiner Certification- Safety Precautions

Welding Inspection and Metallurgy

Objectives

• Introduce the welding process types and their advantages and disadvantages based on intended application, these include:

- Shielded Metal Arc Welding (SMAW)- Gas Tungsten Arc Welding (GT AW)- Gas Metal Arc Welding (GMAW)- Flux Core Arc Welding (FCAW)- Submerged Arc Welding (SAW)- Stud Arc Welding (SW)


Objectives

• Introduce Non-Destructive Examinations methods not covered in previous class lessons and their applications, to include;

- Types of Discontinuities - Materials Identification methods- Visual Examination (VT)- Alternating Current Field Measurement (ACFM)- Eddy Current Inspection (ET)- Hardness Testing- Pressure and Leak Testing (LT)- Weld Inspection Data Recording


Objectives

• Outline basic application of metallurgy to the welding processes, including;

- The Structure of Metals and Alloys - Physical Properties - Mechanical Properties - Preheating - Post-weld Heat Treatment - Hardening - Material Test Reports - Weldability of Steels - Weldability of High-alloys


Objectives

• Present the nature of and remedies for Refinery and Petrochemical Plant Welding Issues, such as;

- General Issues in welding

- Hot Tapping and In-service Welding- Lack of Fusion with GMAW-S Welding Process

Other Items to be discussed

• Welding Terminology and Welding Symbols• Actions to Address Improperly made production

welds.• Guide to common filler metals selection• Example RT reports


Definitions‘Some of the less known’

autogenous weld: A fusion weld made without fillermetal. ( The most common of these types of welds is made on tubing and performed with Gas Tungsten Arc Welding often using an automated welding device)


Definitions

- actual throat: The shortest distance between the weldroot and the face of a fillet weld.


Definitions

- direct current electrode negative (DCEN): Thearrangement of direct current arc welding leads in which theelectrode is the negative pole and work piece is the positivepole of the welding arc. (Commonly known as straight polarity).


Welding Inspection

This Section is to detail the tasks that are considered the responsibility of the Inspection group as well other concerned parties who will design, examine, or perform welding.


Tasks Prior to Welding

• Preplanning will eliminate most mistakes before they happen. A good repair plan will always include a preplanning stage for the welding part of the repair.

Drawings, Codes, Standards requirements should be clearly defined and understood.Quality Control Items to Assess Include:

• Welding symbols and sizes

• Weld joint designs clearly defined

• Weld maps for major projects that specify the WPS used.



Quality Control Items to Assess Include:

• Potential for weld distortion addressed• Welding consumable handling addressed (rod ovens ect.)• Base metal requirements addressed (type, impact tests.)• Mechanical testing required and acceptance criteria• Protection for welding such as wind and rain barriers



Potential Inspector actions:

The inspector’s responsibilities prior to welding can include;

• Look for missing details and information• Determine if the planned testing is adequate• Look for Code and specification violations in the plan • Identify possible welding problems ( Example: inadequate root spacing or a bevel that will not allow full penetration)



Weldment RequirementsQuality Control Items to Assess Include:

• Competency of the Welding Organization to meet requirements of Codes and Standards to be used

• Competency of the Inspection Organization

• The roles and responsibilities of the various parties involved

• Independence of the Inspection Organization from the Production group.



The other issues that the inspector must address as part of tasks prior to welding are;

NDE InformationWelding Equipment and InstrumentsHeat Treatment and Pressure Testing

MaterialsWeld Preparation

PreheatWelding Consumables

The items above are very similar in there language as to the individual of the various group’s responsibilities, concentrate on the INSPECTOR’S tasks during your studies.


Tasks During Welding Operations

Welding inspection during welding operations include things to be checked for conformance to the WPS.

Quality Assurance

• Establish a quality assurance and quality control relationship with the welding organization, the inspector should make it clear what is expected during the job.


During Welding Operations

Quality Control items to assess;

• Make sure all involved know that the welder is responsible for the quality of the welds he makes

• Make sure the welder meets the qualification requirements

• Determine if the welder understands the welding procedure and requirements this includes any inspection hold points.


Tasks During Welding Operations

Welding Parameters and TechniquesQuality Control Items to Assess:

• Make sure essential variables are maintained during welding. Such as;

1. The correct filler metal, fluxes and gasses are used.

2. Purge techniques, flow rate, gas analysis, etc.

3. Rod warmers are used or maximum time out of the rod oven is followed.


Tasks During Welding OperationsQuality Control Items to Assess:

4. Make sure they use the specified preheat during tack welding as well as during the actual welding.

5. Verify equipment setting are in compliance with the WPS. Such as voltage, amperage, wire speed, etc.

6. Verify that interpass temperatures are be observed.

7. Where it applies confirm weld travel speed. This is a key element in control of heat input.


Tasks During Welding OperationsWeldment Examination

Perform visual examination and possibly in-process NDE

Quality Control Items to Assess:

1. Confirm tack welds are acceptable.2. Weld root pass has adequate penetration and quality.3. That cleaning between passes and back gouged surfaces

are adequate.4. Witness or perform NDE between passes as required.5. Verify in-process repairs and defect removal6. Ferrite measurements when required are recorded7. Verify final butt-weld reinforcement or fillet weld size


Tasks During Welding OperationsPotential Inspector Action;

• Reject unacceptable workmanship.


Tasks Upon Completion of Welding

Read and become familiar with all of the following;

Appearance and Finish;Quality Control Items to assess

Inspector action.Other topics include;NDE ReviewPWHTPressure TestingDocumentation AuditNon-Conformances and Defects NDE Examiner Certifications Safety Precautions


1. An autogenous weld is a fusion weld made ____fillermetal.

a. with b. withoutc. with or without

Fill in the blanks:

2. The inspector’s responsibilities prior to welding can include a. ________________b.____________________c._______________________ d.__________________

Class Quiz

1. An autogenous weld is a fusion weld made ____filler metal.

b. without

2. The inspector’s responsibilities prior to welding can include a. ________________ b.____________________c._______________________ d.__________________

a. Look for missing details and informationb. Determine if the planned testing is adequatec. Look for Code and specification violations in the plan d. Identify possible welding problems

Solutions

welding inspection and metallurgy. objectives become familiar with definitions and welding...

Documents

welding arc

metallurgy welding inspection

welding processes

welding preplanning

completion of welding

welding symbolsactions

welding inspections

welding operations tasks