API 577 (Welding Inspection) [exercise]

The correct answer is c. Rockwell, Vickers, Brinell. These three tests are commonly used to measure the hardness of materials. The Rockwell test measures the depth of indentation made by a hard steel ball or diamond cone, the Vickers test measures the size of the indentation made by a diamond pyramid, and the Brinell test measures the diameter of the indentation made by a hard steel ball. These tests are important in determining the strength and durability of materials in various industries.

The mechanical properties of a weldment are mainly influenced by carbon. Carbon is a key element in steel, and its content affects the strength, hardness, and toughness of the material. The presence of carbon allows for the formation of various phases in the steel microstructure, such as ferrite, pearlite, and martensite, which greatly impact the mechanical properties. Higher carbon content generally results in increased strength and hardness, but it can also reduce ductility. Therefore, controlling the carbon content is crucial in achieving the desired mechanical properties in a weldment.

The other expression or abbreviation for penetrameter is I.Q.I.

NDE examination personnel should be qualified to SNT-TC-1A when specified by the referencing code. SNT-TC-1A is a recommended practice for the qualification and certification of nondestructive examination personnel. It provides guidelines for training, experience, and examination requirements for NDE personnel. This ensures that the personnel have the necessary knowledge and skills to perform NDE examinations effectively and accurately.

The number 1 in 7018 indicates the position of welding recommended for this electrode. Different welding positions require different techniques and considerations, and the number 1 helps identify which position is suitable for this particular electrode.

The preferred NDE method to inspect butt joints volumetrically (through the entire weld) is radiographic testing (RT). Radiographic testing involves the use of X-rays or gamma rays to create an image of the weld, allowing for the detection of any internal defects or discontinuities. This method is commonly used in industries such as construction, manufacturing, and oil and gas to ensure the quality and integrity of welds.

A welder continuity log should be written for verification that every welder has utilized each welding process within a six-month period. This ensures that welders are regularly practicing and maintaining their skills in different welding processes. It also helps in tracking the progress and performance of each welder over time. Writing the log every six months allows for a reasonable timeframe to assess the welder's proficiency in various welding techniques.

Hydrogen can come from moisture, lubricants, and damp electrodes in welding. Moisture in the form of water vapor can be present in the air or on the surface of the materials being welded. Lubricants used during the welding process can contain hydrogen, which can be released during welding. Damp electrodes can also contain moisture, which can then release hydrogen when heated during welding. Therefore, all of the above options can be potential sources of hydrogen in welding.

The preheat process is generally monitored by various methods, including the use of thermocouples, contact pyrometers, or even crayons. Thermocouples are temperature sensors that can measure the heat of an object, while contact pyrometers are devices that can measure temperature by making direct contact with the surface. Crayons, on the other hand, are heat-sensitive sticks that melt at specific temperatures, providing a visual indication of the heat level. Therefore, any or all of these methods can be used to monitor preheat.

Low hydrogen electrodes must be stored in a heated oven after initial removal from the package. This is because low hydrogen electrodes are extremely sensitive to moisture and can absorb moisture from the atmosphere, which can lead to hydrogen cracking in the weld. Storing them in a heated oven helps to keep the electrodes dry and prevent moisture absorption, ensuring the quality and integrity of the weld.

The minimum qualification of an NDE examiner who performs radiographic film interpretation is ASNT Level II. This means that the examiner has completed the necessary training and has demonstrated the required knowledge and skills to interpret radiographic films accurately. ASNT Level II is a higher qualification than Level I, III, and IV, indicating a higher level of expertise in radiographic film interpretation.

One of the most common types of fracture toughness tests is the Charpy test. This test measures the amount of energy absorbed by a material when it is subjected to a sudden impact. It involves striking a notched specimen with a pendulum and measuring the energy required to break the material. The Charpy test is widely used to evaluate the toughness and impact resistance of materials, especially in the field of metallurgy.

When welding defects are discovered, the appropriate action to take is to remove the defects and then re-inspect the weld. This ensures that the defects are completely eliminated and the weld meets the required standards. Simply evaluating the defects or conducting tests may not be sufficient to address the issue, as they do not guarantee the removal of the defects. Therefore, the best course of action is to remove the defects and then re-inspect the weld to ensure its quality and integrity.

SMAW, or Shielded Metal Arc Welding, has the advantage of being able to be used on almost all commonly-used metals or alloys. This means that it is a versatile welding process that can be applied to a wide range of materials. This versatility makes SMAW a popular choice in various industries where different types of metals or alloys need to be welded together.

An arc strike refers to a discontinuity caused by an arc, which can lead to localized re-melted metal, heat-affected metal, or a change in the surface profile of a metal object. This can occur when an electric arc unintentionally strikes a metal surface, causing damage or alteration to the material.

The correct answer is d. Not a replacement for AWS CWI training. This means that RP 577 does not provide the same level of learning or training as required for an AWS CWI certification. It suggests that RP 577 should not be considered as a substitute for the training required to become an AWS CWI.

Preheating CS (carbon steel) before welding reduces hydrogen-induced delayed cracking by slowing down the cooling rate and preventing the formation of martensite. Martensite formation is known to be a cause of cracking in steel. By slowing down the cooling rate, the steel is allowed to undergo a more controlled transformation, reducing the likelihood of cracking. This is because slower cooling allows the atoms to rearrange themselves more evenly, reducing the stress and strain on the material.

Welding inspection is an important part of the Quality Assurance program. Quality Assurance ensures that all processes and products meet the required standards and specifications. Welding inspection plays a crucial role in ensuring the quality of welded joints, identifying any defects or issues, and ensuring that the welding process meets the required standards. It helps in preventing potential failures, ensuring the structural integrity of the welded components, and maintaining the overall quality of the final product. Therefore, welding inspection is an integral part of the Quality Assurance program.

The term "defect" refers to a flaw or imperfection in a product or system. It suggests that there is something wrong or not up to standard. The term "rejectable" further emphasizes the severity of the flaw, indicating that it is not acceptable and should be rejected. Therefore, option d, "A rejectable flaw," is the most appropriate synonym for a defect.

The most common measure of weldability and hot cracking of stainless steel is the Ferrite number. This number indicates the amount of ferrite present in the microstructure of the stainless steel weld. Ferrite is a type of iron that can help improve the weldability of stainless steel by reducing the risk of hot cracking. By measuring the Ferrite number, engineers and welders can determine the optimal welding parameters and ensure that the stainless steel weld has the desired properties.

Prior to welding, it is important to check all of the above mentioned factors. Confirming the qualifications of NDE examiners ensures that they are capable of performing the necessary non-destructive examinations. Reviewing WPS, PQR, and WPQ's helps to ensure that the welding procedures, qualifications, and performance records are in compliance with the required standards. Additionally, confirming the acceptability of heat treatment procedures ensures that the necessary heat treatment has been carried out correctly. Therefore, all of these factors should be checked prior to welding to ensure the quality and safety of the welding process.

Due to the similarities in the shape of the grains and cooling characteristics, a weld can be called a small casting. Casting involves pouring molten metal into a mold and allowing it to solidify, which is similar to the process of welding where metal is melted and fused together. The grains formed during solidification in both casting and welding can have similar shapes and cooling characteristics, making the term "casting" an appropriate description for a weld.

LOF stands for Lack of Fusion, which is a common weld defect in the GMAW-S (Gas Metal Arc Welding - Short Circuit) process. Lack of fusion occurs when there is inadequate bonding between the weld metal and the base metal, resulting in a weak joint. This defect can lead to structural integrity issues and potential failure of the welded component.

Short circuiting is the coolest or fastest freezing transfer mode of GMAW. In this mode, the wire electrode makes contact with the weld pool and creates a short circuit, causing the wire to melt and transfer metal droplets to the workpiece. This process is characterized by low heat input and a relatively low deposition rate, resulting in a cooler and faster freezing weld. Pulse-spray, spray, and globular transfer modes have higher heat inputs and deposition rates, making them less cool and slower freezing compared to short circuiting.

One of the unusual aspects of SAW is that the arc is not visible during welding.

GTAW (Gas Tungsten Arc Welding) and SMAW (Shielded Metal Arc Welding) are both welding processes that require a constant current (cc) power supply. Unlike other processes that may use constant voltage (cv) power supplies, GTAW and SMAW rely on cc power supplies to provide a stable and consistent current for the welding operation. This allows for better control and precision during the welding process. The use of cc power supplies is a key characteristic that distinguishes GTAW and SMAW from other welding processes.

When aluminum (Al) and magnesium (Mg) are welded using the Gas Tungsten Arc Welding (GTAW) process, alternating current (AC) is generally used. AC allows for better control of the heat input and helps prevent excessive melting or distortion of the base metals. Additionally, AC helps to clean the surface of the weld and remove any oxide layers, resulting in a stronger and more reliable weld joint.

Undercut is a welding defect that occurs at the weld interface. It is characterized by a groove or depression in the base metal adjacent to the weld. Undercut is typically caused by excessive heat or improper welding technique, which leads to the melting and removal of the base metal at the weld interface. This defect weakens the weld joint and can result in structural failure. Therefore, it is important to properly control the welding parameters and ensure proper fusion between the base metal and weld metal to prevent undercut.

The limitation of the FCAW process is slag removal. FCAW (Flux-Cored Arc Welding) involves the use of a flux-cored electrode that creates a protective shield of gas around the weld. This process produces slag, which is a byproduct that forms on the surface of the weld. Slag removal can be time-consuming and labor-intensive, requiring additional cleaning and grinding to achieve a smooth and clean weld.

When the CE (Carbon Equivalent) number of steel is above 0.55, it indicates a higher risk of cracking during welding. To prevent this, preheating the steel before welding is recommended. Preheating helps to reduce the cooling rate and minimize the risk of cracking. Additionally, Post Weld Heat Treatment (PWHT) is also advised. PWHT involves heating the welded steel to a specific temperature and holding it there for a certain period of time. This process helps to relieve residual stresses and improve the overall strength and integrity of the welded joint. Therefore, the correct answer is d. Preheat and PWHT.

A constant voltage power supply is an arc welding power source that maintains a consistent voltage output regardless of changes in the welding current. This means that even with small changes in voltage, there will be a large change in welding current. This type of power supply is commonly used in applications where maintaining a stable voltage is crucial for achieving desired welding results.

ACFM stands for Alternating Current Field Measurement, which is a non-destructive evaluation (NDE) technique used to detect surface indications in carbon, alloy, and stainless steel. This technique uses electromagnetic fields to identify any surface defects or flaws in the material being inspected. It is particularly effective in identifying cracks, corrosion, and other surface irregularities that may compromise the integrity of the steel. It should be noted that ACFM is not capable of detecting sub-surface indications or flaws in carbon steel, as indicated in the other options.

F numbers are assigned to electrodes based on their usability characteristics. This means that the F number indicates the usability of the electrode in terms of its performance, efficiency, and suitability for specific welding applications. The F number system helps welders select the appropriate electrode for their specific needs, considering factors such as weld position, type of joint, and welding process.

A material with high thermal conductivity requires a higher heat input to weld because it can quickly dissipate heat. This means that more heat needs to be applied during the welding process to ensure that the material reaches the desired temperature for proper joining. If the heat input is too low, the material may not reach the necessary temperature for welding, resulting in a weak or incomplete weld.

ACFM (Alternating Current Field Measurement) is a non-destructive testing technique used to detect and measure surface-breaking cracks in metals. One of its features is that it does not require calibration standards. This means that it does not need to be calibrated against known standards or reference materials to ensure accurate measurements. This feature simplifies the testing process and allows for more efficient and cost-effective inspections.

Hydrogen cracking, also known as cold cracking or delayed cracking, is a type of welding defect that occurs when hydrogen atoms become trapped in the weld metal and cause it to crack. It is commonly associated with processes that produce high levels of hydrogen, such as shielded metal arc welding (SMAW), flux-cored arc welding (FCAW), and submerged arc welding (SAW). However, gas metal arc welding (GMAW), also known as MIG welding, typically does not produce high levels of hydrogen and therefore is less prone to hydrogen cracking. Therefore, the correct answer is d. GMAW.

Slightly damp low hydrogen electrodes should be re-baked in special ovens. This is because low hydrogen electrodes are designed to have a low moisture content, and any moisture present can negatively affect the quality of the weld. Re-baking the electrodes in special ovens helps to remove the moisture and restore the electrodes to their proper condition for use.

Under-bead cracking refers to the formation of cracks in the heat-affected zone (HAZ) of a weld. The HAZ is the area surrounding the weld where the base metal has been heated and cooled during the welding process. This area is prone to cracking due to the high levels of residual stress and changes in microstructure caused by the welding heat. Therefore, it is common to find under-bead cracking in the HAZ of a weld.

The approximate CE (Carbon Equivalent) of this material can be calculated using the formula supplied in RP 577. The formula for CE is: CE = C + (Mn/6) + (Cr+Mo+V)/5 + (Ni+Cu)/15. Plugging in the values given in the material test report, we get CE = 0.15 + (0.20/6) + (1.25+1.00+0.02)/5 + (0.35+0.01)/15 = 0.7. Therefore, the approximate CE of this material is 0.7, which matches option c.

Incomplete penetration is a welding defect where the weld metal fails to fuse completely with the root of the joint. In austenitic stainless steel, this can be caused by several factors, including:

Travel speed: If the travel speed is too fast, the weld metal may not have enough time to penetrate the root of the joint.

Heat input: Insufficient heat input can also lead to incomplete penetration, as the weld metal may not reach the melting temperature of the base metal.

Ferrite content: The ferrite content of the weld metal can also affect penetration. A higher ferrite content can improve penetration, but it can also reduce the corrosion resistance of the weld.

Therefore, all of the options listed can be used to correct incomplete penetration in austenitic stainless steel.