AWS Certified Welding Inspector — Fundamentals

D. Unacceptable, because it violates both the absolute undersize limit and the percentage reduction limit.

Specified weld size = 1/4 inch (6 mm). Measured weld size = 3/16 inch (4.8 mm). Undersize = 1/4 - 3/16 = 1/16 inch (1.6 mm). The code allows a maximum undersize of 1/16 inch (1.6 mm), so this is at the limit. However, the code also states 'provided the reduction does not exceed 10% of the specified size.' 10% of 1/4 inch (6 mm) is 0.025 inch (0.6 mm). Since the actual undersize (1/16 inch or 1.6 mm) is greater than 10% of the specified size (0.025 inch or 0.6 mm), the weld is unacceptable.

D. Depletion of chromium at grain boundaries, leading to intergranular corrosion.

Sensitization in austenitic stainless steels (like 304L) occurs when exposed to temperatures in the range of approximately 800-1500°F (425-815°C) for a sufficient time. During this exposure, chromium carbides precipitate at the grain boundaries, which depletes the adjacent regions of chromium, making them susceptible to intergranular corrosion. Excessive heat input during welding can keep the HAZ in this temperature range for too long, promoting sensitization.

B. Inform the project manager of the missing document and state that the final report cannot be issued until all required documentation is complete.

The CWI cannot issue a complete final inspection report if required documentation is missing. The RT report is a critical component of the weld's acceptance record. The CWI's obligation is to ensure all documentation is complete and compliant before certifying the work. Informing the project manager is the appropriate step to initiate resolution.

B. Presence of low melting point constituents at grain boundaries.

Solidification cracking (also known as hot cracking) occurs when low melting point constituents are present at grain boundaries during the final stages of solidification. As the weld metal contracts, these liquid films cannot withstand the tensile stresses, leading to cracks. High carbon equivalent is related to hydrogen cracking, a narrow freezing range generally reduces hot cracking, and high fluidity doesn't directly cause solidification cracking.

D. A change from stringer bead to weave bead technique.

In most welding codes (e.g., AWS D1.1, ASME Section IX), a change in technique from stringer bead to weave bead is typically considered a non-essential variable. This means it can be changed without requiring requalification of the WPS. The other options (change in P-number, significant decrease in preheat, change in electrode classification) are generally considered essential or supplementary essential variables that would require requalification.

B. The welder needs to qualify specifically for the 4F position.

According to AWS D1.1, a 3G (vertical groove) qualification covers 1G, 2G, and 3G groove positions, and 1F, 2F, and 3F fillet positions. It does NOT cover the 4F (overhead fillet) position. Therefore, the welder would need to specifically qualify for the 4F position to perform overhead fillet welds.

A. Politely refuse the request and explain that the inspection must be performed as per the project specifications and governing codes.

A CWI's primary ethical responsibility is to ensure compliance with project specifications and governing codes, regardless of pressure from management or clients. Compromising inspection standards for expediency is a serious ethical breach that can jeopardize safety and quality. The CWI must uphold the specified inspection requirements.

B. Instruct the welder to thoroughly remove all slag and visually inspect the surface before allowing the next pass.

Even if the WPS doesn't explicitly detail slag removal, the governing code's requirement for a clean surface between passes takes precedence. Slag inclusions can lead to lack of fusion and other critical defects in the final weld. The CWI must ensure this is addressed immediately.

B. Phosphorus (P)

Temper embrittlement in low-alloy steels (like 2.25Cr-1Mo) is a form of embrittlement that occurs when the steel is held or slowly cooled through a specific temperature range (typically 750-1100°F or 400-600°C). It is caused by the segregation of certain impurity elements to grain boundaries, with phosphorus (P) being the most potent and common contributor, followed by tin (Sn), antimony (Sb), and arsenic (As).

A. Implementing adequate preheating and controlled interpass temperatures.

A high carbon equivalent (CE) indicates increased hardenability and a higher susceptibility to cold cracking (hydrogen-induced cracking). To mitigate this, preheating is crucial to slow the cooling rate, allowing hydrogen to diffuse out and preventing the formation of brittle martensite. Controlled interpass temperatures maintain this slower cooling effect.

A. Document the undersized weld and issue a Non-Conformance Report (NCR).

According to AWS D1.1, undersized fillet welds are considered defects if they fall below specified tolerance limits. For a 5/16-inch fillet weld, a consistent 1/4-inch leg size (1/16 inch undersize) exceeds the typical permissible undersize of 1/32 inch for fillet welds less than 3/8 inch. Therefore, it is a non-conformance that must be documented and addressed.

A. Undercut

Undercut is a groove melted into the base metal adjacent to the toe or root of a weld and left unfilled by weld metal. The description of a 'continuous, shallow groove along the toe of the weld' perfectly matches the definition of undercut.

D. Stop the welding operation immediately and require that the equipment be repaired or replaced before resuming.

Consistent fluctuation of welding current outside the WPS-specified range due to equipment malfunction is a critical non-conformance. This directly impacts weld quality and can lead to defects. The CWI must stop the operation to prevent further unacceptable welds until the equipment is rectified.

A. Decline the assignment to avoid a conflict of interest and maintain impartiality.

The AWS Code of Ethics for Certified Welding Inspectors explicitly states that inspectors shall avoid conflicts of interest. Having a personal financial interest in the fabrication company compromises impartiality and creates a direct conflict of interest, making it impossible to perform duties objectively. The CWI must decline the assignment.

C. Hydrogen-induced cracking (HIC).

The description points strongly to Hydrogen-Induced Cracking (HIC), also known as cold cracking. Key indicators are: 'intergranular cracks in the HAZ' (a common site for HIC), 'high-strength low-alloy (HSLA) steel' (susceptible to HIC), occurrence 'several hours after welding' (delayed cracking characteristic of HIC), and 'non-metallic inclusions' (which can act as hydrogen traps and stress concentrators). High restraint also exacerbates HIC.

B. Report the non-compliance to the project management or client for appropriate action.

The CWI has a professional and ethical responsibility to ensure that all personnel meet project requirements, including certification standards. Discovering a non-compliance with the QC manual mandates reporting it to the appropriate authority for resolution, not ignoring it or handling it privately.

C. Unacceptable, as the reinforcement exceeds the specified maximum and must be reduced.

Excessive weld reinforcement, even if it blends smoothly, creates stress risers and can be a non-conformance. The WPS specifies a maximum of 1/8 inch, and 3/16 inch clearly exceeds this. According to AWS D1.1, reinforcement must be within specified limits. Thus, these welds are unacceptable and require grinding down to the specified limits.

B. Excessively high interpass temperatures can degrade the mechanical properties of HSLA steels.

For HSLA steels, maintaining interpass temperature within a specific range is critical. While preheat helps prevent hydrogen cracking (associated with low temperatures), excessively high interpass temperatures can lead to grain growth, loss of strength, and reduced toughness in the heat-affected zone (HAZ) of HSLA steels. API 1104, while less prescriptive than ASME, expects the WPS to control these critical variables to maintain mechanical properties.

C. Quarantine the affected electrodes and prevent their use until they can be properly reconditioned or discarded.

Low-hydrogen electrodes are highly susceptible to moisture absorption, which can introduce hydrogen into the weld metal and cause hydrogen-induced cracking. Storing them in an open, unheated area is a critical violation of storage requirements. The CWI must immediately quarantine these electrodes to prevent their use, as they are likely compromised. Reconditioning may be an option, but preventing use is paramount.

C. The welder's qualification does not cover the specific electrode and material combination for the root pass.

The primary concern is that the welder's qualification may not extend to the specific combination of P-number material and electrode type (E7018 for root pass) required by the project specifications, even if 6010 is generally acceptable for other applications. Qualification is often specific to electrode type or grouping, especially for critical applications like root passes on certain materials, and the project specification reinforces this. Option D is part of C, but C is more comprehensive.

D. Immediately halt all welding operations on critical welds until the specified inspection rates are met.

The CWI's primary responsibility is to ensure compliance with the specified quality control plan. Failure to perform mandated inspections, especially NDT methods like MT and RT for critical welds, is a severe non-conformance that directly impacts weld integrity and safety. Halting operations is necessary to prevent further non-compliant work and potential safety hazards.

A. Undercut

Undercut is a groove melted into the base metal adjacent to the toe or root of a weld and left unfilled by weld metal. It reduces the base metal thickness and can act as a stress concentrator.

C. Instruct the welding operator to immediately cease operations until the filler metal storage issue is rectified.

The CWI's primary responsibility is to ensure compliance with the WPS and prevent defective work. Improper storage of low-hydrogen electrodes can lead to hydrogen-induced cracking, a critical defect. Halting operations is necessary to prevent potential defects.

C. Issue a non-conformance report (NCR) and inform all relevant parties that the NDT results are invalid due to improper certification.

The project specification clearly outlines the certification requirements for NDT personnel (ASNT SNT-TC-1A, Level II or III, by an ASNT NDT Level III). A technician certified only by an in-house program, without the specified ASNT Level III oversight, means the NDT was performed by unqualified personnel according to the project requirements. The results are invalid, and an NCR must be issued immediately.

B. Require the welder to immediately stop work and adjust the travel speed to comply with the WPS.

Travel speed is an essential variable in most welding processes, directly impacting heat input, penetration, and weld quality. Deviating from the WPS without approval makes the weld non-compliant. The CWI must ensure adherence to the WPS during welding.