Welding cracking

Atomic hydrogen welding Corrosion effect of welding Cracking tendency Prefabrication treatment effects Electric flash welding Flux... 

Estimate air leakage into the system based on possible weld cracks, metal weld, or metal porosity ... 

F. Feed/effluent exchanger nozzle-to-shell weld, cracks in welds and in exchanger tubes. 

Circumferencial weld crack leaded propane which ignited resulting in a vapor cloud. Resulting explosion and fires severely damaged facility. 

Leaks due to weld cracks resulting from thermal cycling or high stress may occur at any of the weld connections. 

A program for acoustic emission under the name Monopac was developed for external and internal corrosion, stress corrosion cracking and weld cracking.55 This program consists of the test procedures as well as case histories. 

In selecting a suitable filler alloy, a proper balancing of the desirable qualities of high tensile strength, good elongation, and freedom from weld cracking must be made. The... 

In the environmental series, nickel is nobler than iron but more active than copper. Reducing environments, such as dilute sulfuric acid, find nickel more corrosion resistant than iron but not as resistant as copper or nickel-copper alloys. The nickel molybdenum alloys are more corrosion resistant to a reducing environment than nickel or nickel-copper alloys [16]. Nickel-based superalloys are extremely prone to weld cracking. 

Nil-ductility transition temperature Fracture toughness Dynamic Tndt Blunt changes to sharp Sharp crack Drop-weight specimen test e.g., ASTM E 208. Uses brittle weld crack starter on test specimen. Propagation test Fracture toughness test of fatigue pre-cracked... 

The use of precracked SCC specimens is necessary for some metals in which an SCC flaw will not initiate, but in which other types of flaws such as weld cracks can propagate by SCC. This is not necessary for aluminum alloys, which will initiate a SCC flaw on an unflawed, smooth specimen. Most SCC testing of aluminum has been done using smooth specimens because these specimens and test methods are faster and less expensive. Although the data from the two types of testing are not interchangeable, both methods tend to rank aluminum alloys in the Scune relative order of increasing resistance to SCC [20]. 

If the project involves demolition and refurbishment, then information on the occupancy of the premises or nearby premises needs to be ascertained. A structural survey should be made of the building to investigate the types of structural defect that may be apparent during a visual inspection and explain the causes of those defects. Typical defects include corrosion of steelwork, cracking due to fatigue in structural steel and welds, cracked brickwork and concrete, concrete degradation (flaking), dropped lintels and... 

What Visually inspect restraining devices and barriers for Cracks at welds Cracked or broken components Bent or sprung components caused by mishandling, abuse, tire expiosion, or rim wheel separation Pitting components due to corrosion or Other structurai damage which would decrease its effectiveness. Defective equipment must be immediately removed from service. 

Standard structural shapes, including pipe, which makes an excellent structural shape, can be used. Electrodes such as the E6OIO-II types are often the welder s first choice for this kind of fabrication welding because of their all-position characteristics. These electrodes, which are not low-hydrogen types, may be used providing the weldability of the steel is such that neither weld cracks nor severe porosity is likely to occur. 

This alloy is readily fabricated and has excellent resistance to post-weld cracking. Excellent oxidation resistance is displayed up to 1800°F (952°C). Alloy 718 is resistant to sulfuric acid, organic acids, and alkalies. It is also resistant to chloride SCC. Hydrochloric, hydrofluoric, phosphoric and nitric... 

NOTE Any repair weld cracking, well defined (especially open)... 

NOTE Any repair weld cracking, well defined (especially open) cracks in stress or load-bearing areas, cracks through 20 percent or more original welds or parent metal. 

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