API API-577 Practice Exam Questions & Answers
7 Free Questions
· Last reviewed: October 25, 2026
· Prepared & Reviewed by the ValidExamDumps Editorial Team
Exam Facts
API API-577 Exam Details
Key details for this exam, checked against the published exam outline
110
Practice Questions (Our Bank)
110 minutes
Exam Duration
Scaled score of 400 out of 500
Passing Score
- Exam Code
- API-577
- Full Name
- API 577 Certification: Welding Inspection and Metallurgy
- Issuing Body
- American Petroleum Institute (API)
- Question Format (Our Bank)
- Multiple Choice
- Delivery
- In-person test centers or remote proctored
- Eligibility
- Current API 510, 570, or 653 certification holders qualify automatically. Otherwise, qualification is based on a combination of education level and industry experience acquired within the last 10 years.
Practice Questions
Free API-577 Practice Questions
Each question shows the correct answer and an explanation of why it is right
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Eddy current can be used to measure the:
Correct Answer:
B
Explanation
A PQR (Procedure Qualification Record) documents the results of welding a test coupon to qualify a WPS (Welding Procedure Specification). For SMAW (Shielded Metal Arc Welding), the PQR must record the welding process used and the P-numbers of the base metals in the coupon. P-numbers group similar metals for qualification purposes. Without documenting the specific process and base metal P-numbers, the qualification would not be valid or traceable to the procedure being qualified.
Heating a round bar to an elevated temperature and then quenching one end is a test method to determine:
Correct Answer:
A
Explanation
Lamellar tearing is a type of crack that forms below the weld surface in a step-like or terraced pattern. It occurs in thick sections of alloy steel where residual stresses act through the thickness. Planar-shaped inclusions, typically oxides and silicates, weaken the steel and provide planes where cracks can propagate. The crack path follows these inclusion layers, creating the characteristic subsurface stepped appearance. Other weld flaws do not produce this specific combination of subsurface location and inclusion-influenced terraced fracture pattern.
To avoid burn through during in-service welding on thinner wall equipment, it is generally recommended to:
Correct Answer:
B
Explanation
This test is called the end-quench or Jominy test, and it measures hardenability. A round bar is heated to the austenitizing temperature then water-quenched at one end. The rapid cooling at the quenched end produces maximum hardness (martensitic structure), while slower cooling deeper into the bar produces softer structures. By measuring hardness at different distances from the quenched end, you can determine how deeply the steel hardens. This directly indicates the material's hardenability, which is critical for predicting behavior in welded joints.
A ''mill certificate" is a/an:
Correct Answer:
C
Explanation
When a test specimen from a PQR coupon fails during mechanical testing, the entire coupon is considered to have failed qualification. A new coupon must be prepared and tested. You cannot simply re-test another specimen from the same coupon or move forward with partial results. This requirement ensures that the welder and procedure have been properly validated. The strict standard protects the integrity of the qualification record and the quality of production welds.
What term is used to describe the mechanical working of metals using impact blows?
Correct Answer:
D
Explanation
High hardness in alloy steel can indicate the presence of untempered martensite, which is hard but brittle. Martensite forms when steel cools rapidly from high temperature, and it becomes harder and more brittle if not tempered. Untempered martensite is undesirable in most applications because it lacks toughness and can fail suddenly under stress. Other microstructures like ferrite, pearlite, or tempered martensite would show lower hardness values. Identifying high hardness alerts inspectors to potential toughness problems in the material or weld.
What is the purpose of the IQI?
Correct Answer:
A
Explanation
For 1-1/4 Cr-1/2 Mo steel used in refinery service, the maximum allowable Brinell hardness is 225. This limit protects against hydrogen cracking and maintains adequate toughness in service. Refinery and petrochemical applications are particularly sensitive to hard, brittle microstructures that can fail in corrosive environments under stress. ASME and API standards specify this hardness limit for this material in these applications. Hardness values above 225 would indicate a risk of service failure and require remedial action.
Codes/standards sometimes specify impact testing of weldments at minimum design metal temperatures to:
Correct Answer:
C
Explanation
When using radiographic examination for welder qualification with GMAW-S (gas metal arc welding, short arc), the test coupon must be at least 6 inches in length for the examined section. This minimum length ensures adequate representation of the welder's ability to maintain consistent penetration and fusion over a practical weld length. Shorter lengths would not adequately demonstrate skill and consistency. The 6-inch minimum is established in ASME and AWS codes to provide a meaningful qualification test that relates to production welding reality.
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Domain 1: Welding Processes
Demonstrates comprehensive knowledge of various welding techniques, including equipment details and their applications. Requires understanding of the principles behind each welding process and the ability to evaluate process suitability for different materials and situations.
Domain 2: Welding Materials
Focuses on understanding types of metals, alloys, and consumables used in welding. Includes material properties, selection criteria, and compatibility issues.
Domain 3: Welding Procedure
Tests knowledge of developing, qualifying, and implementing welding procedure specifications (WPS). Covers the requirements and methods for establishing procedures that meet industry standards.
Sample question from this domain above:
Q1
Domain 4: Welder Qualification
Evaluates understanding of welder qualification processes, including requirements, methods, and documentation for certifying welders. Familiarity with relevant codes and standards is essential.
Sample questions from this domain above:
Q4Q7
Domain 5: Nondestructive Examination (NDE)
Demonstrates proficiency in various NDE methods and covers principles and applications of NDE techniques in welding inspection. Includes radiographic, ultrasonic, magnetic particle, and liquid penetrant examination methods.
Domain 6: Welding Inspection
Assesses skills in performing welding inspections, including inspection techniques, tools, and documentation requirements. Covers visual inspection and the identification of weld defects.
Domain 7: Metallurgy
Showcases expertise in welding metallurgy, focusing on effects of welding on material properties. Includes topics on heat-affected zones and microstructure changes.
Sample questions from this domain above:
Q2Q3Q5
Domain 8: Refinery and Petrochemical Plant Welding Issues
Addresses welding challenges specific to refinery and petrochemical plant environments, including materials, unique challenges, and safety considerations in these industries.
Sample question from this domain above:
Q6
Domain 9: Safety Precautions
Tests knowledge of safety precautions in welding operations, covering personal protective equipment (PPE), hazard identification, and safety procedures.
FAQ
API-577 Exam FAQ
Common questions about the exam itself
What prior experience or certification do I need to qualify for API 577?
If you hold a current API 510, 570, or 653 certification, you automatically qualify. If not, you need a combination of education and industry experience acquired within the last 10 years. Specific requirements vary by education level and are detailed on the API application.
How difficult is the API 577 exam and what makes it challenging?
API 577 is a comprehensive exam testing specialized knowledge in welding inspection and metallurgy across nine domains. The difficulty comes from the breadth of technical content, the closed-book format, and the requirement to understand principles not just definitions.
Which topic in API 577 do most candidates find hardest to prepare for?
Metallurgy and the effects of welding on material microstructure are often the most challenging because they require understanding heat-affected zones and material property changes at a deeper level than other topics.
How long should I realistically prepare for the API 577 exam?
Preparation time depends on your background, but most candidates benefit from between 4 to 8 weeks of focused study, especially if you need to review metallurgy and nondestructive examination techniques.
What happens on exam day for API 577 and what can I bring?
You will sit for a 195-minute closed-book exam with 110 questions (100 scored, 10 pretest). No paper, reference materials, or notes are allowed in the test center or during remote proctoring.
What is the passing score for API 577 and how is it calculated?
API 577 uses a scaled scoring system where the passing score is 400 out of 500. The scaled score is calculated from your raw score to ensure fair comparison across different exam forms taken on different dates.
How long is the API 577 certification valid and what renewal requires?
Your API 577 certification is valid for three years. At this time, employment verification is not required to recertify, though you must submit your recertification application within 90 days before your certification expires.
What job roles does API 577 certification prepare you for?
API 577 is designed for specialized inspectors, welding engineers, metallurgists, and other professionals in the petrochemical and refining industries who perform welding inspections and need formal validation of their expertise.
How does API 577 relate to other API inspector certifications like API 510 and API 570?
API 577 is the welding specialty certification, while API 510 covers pressure vessels and API 570 covers piping. Holding a current API 510, 570, or 653 certification automatically qualifies you for API 577, and the certifications often work together in inspection programs.
Can I retake API 577 if I fail the first time and are there rescheduling options?
Yes, you can retake API 577. Retake rules and scheduling options depend on API's current policies, which you should verify with API or your exam delivery provider when you receive your results.
