: Standard computer monitors cannot replicate the precise optical density required to grade actual X-rays accurately.
ASTM E155, titled "Standard Reference Radiographs for Inspection of Aluminum and Magnesium Castings," provides a set of reference radiographs (X-ray films or digital equivalents) that illustrate typical discontinuities. These standards are developed by the American Society for Testing and Materials (ASTM) to provide a universal baseline. Instead of guessing whether a casting is fit for service, inspectors compare production radiographs directly against these master references.
Porosity in castings primarily occurs due to trapped gas (usually hydrogen in aluminum) or volumetric contraction during solidification. ASTM E155 categorizes these discontinuities into specific , typically ranging from Level 1 to Level 8 .
ASTM E155 Discontinuity Levels Guide | PDF | Materials - Scribd astm e155 porosity levels pdf repack
If you’ve already obtained this “repack,” I strongly advise scanning it for security risks and verifying its contents against an official copy before any professional use.
: Round, elongated, or pocket-like voids caused by trapped gas (usually hydrogen in aluminum) during solidification.
The standard keyword is not just about downloading a file. It represents a specific need in the NDT community. Here is why a well-organized "repack" matters: : Standard computer monitors cannot replicate the precise
Understanding ASTM E155 Porosity Levels: A Guide to Radiographic Inspection and PDF Repack Resources
Jagged, angular voids caused by metal contraction during solidification. Foreign material: Inclusions of lighter or heavier density.
Designers often apply different levels to the same part; critical thin "arms" may require Level 1, while thicker "truck" areas might allow Level 3. Instead of guessing whether a casting is fit
| Fault Type | Thickness Reference Part | Severity Level | |---|---|---| | Gas inclusions | 1/4″ (6.35 mm) | Levels 1, 3, 5, 6 | | Gas inclusions | 3/4″ (19.1 mm) | Levels 1, 3, 5, 6 | | Gas pores (round) | 1/4″ (6.35 mm) | Levels 2, 3, 5, 7 | | Gas pores (elongated) | 1/4″ (6.35 mm) | Levels 2, 4, 5, 6 | | Shrinkage porosity (spongy) | 1/4″ (6.35 mm) | Levels 2, 3, 5, 6 |
The ASTM E155 standard defines four levels of porosity in steel castings, ranging from Level I (no porosity) to Level IV (severe porosity). The levels are based on the size and distribution of pores within the casting.
Microshrinkage having an elongated appearance resembling feather-like streaks. 4. Microshrinkage (Sponge Type)
| Level | Description | Typical Disposition | |-------|-------------|----------------------| | | Very fine, widely scattered pores – barely detectable under standard viewing conditions. | Always acceptable for most applications. | | Level 2 | Small pores, still scattered but more frequent. | Acceptable for general commercial use. | | Level 3 | Moderate pore size and frequency. The "gray area" – often requires engineering review. | Acceptable only with reduction factors. | | Level 4 | Coarse pores, frequent clustering, measurable loss of section integrity. | Usually rejectable for structural parts. | | Level 5 | Severe porosity – gross discontinuities visible without viewers. | Unacceptable for all but the lowest-grade castings. |