Metallurgical Testing

Our metallurgical testing capabilities include several processes for evaluating project materials, testing adherence, identifying contaminants and instances of material failure. This information is provided to our customers as a result of several testing mechanisms we offer.

Corrosion testing services provide the instrumentation and expertise to scientifically determine the rate and intensity at which any metal type will corrode under certain accelerated conditions. This information is critical for determining pipe wall thickness and applied to materials selection for tubes and tanks. Corrosion testing surpasses visual inspection by which it is impossible to determine a material’s interior condition. This type of testing also is beneficial with bridge supports and other types of structural steel beams and pilings. This service is necessary to avoid dangerous structural failures on construction applications and completed projects.

Southern Inspection also has the capability to create high-end machined products according to our customer’s specifications. Our knowledge of material specification and construction codes ensures the most suitable end product for tools, parts and repair work requested by our customers. Our skilled craftsman work with the best machining tools and equipment necessary for inspection testing projects.

Our customers often request initial visual materials inspection from our facility, on site and in remote work environments. Our breadth of industry knowledge ensures proper and accurate identification of material conditions. If our staff identifies complex issues requiring further testing, it is immediately reported to our customers. No matter how hard to reach your inspection site may be, Southern Inspection can get the job done.

Positive Material Identification (PMI)

Positive Material Identification (PMI) is the analysis of a metallic alloy to establish composition by reading the percentage quantities of its constituent elements. The object of this nondestructive testing method is to identify metal alloys in place using a portable X-Ray fluorescent analyzer that determines the elemental composition of the material.

Southern Inspection applies PMI:

1. To test ferrous and non-ferrous metallic materials, stainless steels, Monels, Inconels, Hastelloys,
Aluminum alloys, nickel based alloys, exotic materials
2. While verifying material compliance in power and petrochemical industries
3. To inspect valves and valve components, pipe, fittings, machined parts, castings, forgings, bolts
and stock items
4. To inspect welds and weld overlays
5. To verify compliance of new and in-service pressure vessels, plate material, and structural steel

ADVANTAGES
Rapid and accurate analysis
Highly portable digital technology, can be used on site
Certifies components requiring NACE MR0175/ISO 15156
Leaves no trace of testing on test sample
Care must be taken to ensure that the surface of the test specimen is representative of the material as a whole
The instrument must be able to maintain surface contact with the material

LIMITATIONS
The depth of penetration of the x-ray for most elements is less than one thousandth of an inch in steel. Care must be taken to ensure that the surface of the material being analyzed is chemically representative of the whole.
Surface of the item must be accessible and subject to satisfactory cleaning and visual inspection
Analyzers are limited to identifying only those alloys that are listed in the manufacturer’s library for the analyzer
Material verification cannot be performed where the material temperature is in excess of approximately 200°F, unless specialized equipment and techniques are used
Identification of small amounts of a specific element in an item can be difficult
Carbon, sulfur and phosphorous cannot be identified with x-ray fluorescence

PMI FUNDAMENTALS

Typical methods for PMI include X-ray fluorescence (XRF) and optical emission spectrometry (OES). IRISNDT carries out PMI using the latest portable analyzers. All analyzers have a margin of error that varies by element and activity of the radioactive source. The identification of small amounts of a specific element in an item can be difficult. Test results are summarized in an inspection report.

Hardness Testing

What is Hardness?

Hardness is the property of a material that enables it to resist plastic deformation, usually by penetration. However, the term hardness may also refer to resistance to bending, scratching, abrasion or cutting.

Measurement of Hardness:

Hardness is not an intrinsic material property dictated by precise definitions in terms of fundamental units of mass, length and time. A hardness property value is the result of a defined measurement procedure. Hardness of materials has probably long been assessed by resistance to scratching or cutting. An example would be material B scratches material C, but not material A. Alternatively, material A scratches material B slightly and scratches material C heavily. Relative hardness of minerals can be assessed by reference to the Moh's Scale that ranks the ability of materials to resist scratching by another material. Similar methods of relative hardness assessment are still commonly used today. An example is the file test where a file tempered to a desired hardness is rubbed on the test material surface. If the file slides without biting or marking the surface, the test material would be considered harder than the file. If the file bites or marks the surface, the test material would be considered softer than the file.

The above relative hardness tests are limited in practical use and do not provide accurate numeric data or scales particularly for modern day metals and materials. The usual method to achieve a hardness value is to measure the depth or area of an indentation left by an indenter of a specific shape, with a specific force applied for a specific time. There are three principal standard test methods for expressing the relationship between hardness and the size of the impression, these being Brinell, Vickers, and Rockwell. For practical and calibration reasons, each of these methods is divided into a range of scales, defined by a combination of applied load and indenter geometry.

Hardness Test Methods:

Rockwell Hardness Test
Rockwell Superficial Hardness Test
Brinell Hardness Test
Vickers Hardness Test
Microhardness Test
Moh's Hardness Test
Scleroscope Hardness Test
The Durometer

Hardness Conversion or Equivalents:

Hardness conversion between different methods and scales cannot be made mathematically exact for a wide range of materials. Different loads, different shape of indeters, homogeneity of specimen, cold working properties and elastic properties all complicate the problem. All tables and charts should be considered as giving approximate equivalents, particularly when converting to a method or scale which is not physically possible for the particular test material and thus cannot be verified. An example would be converting HV/10 or HR-15N value on a thin coating to the HRC equivalent.

Ferrite Testing

Ferrite content analysis is a non-destructive testing method which provides critical data for austenitic stainless steel and duplex materials. The delta ferrite percentage or number allows a technical assessment of material corrosion susceptibility, mechanical properties, service suitability, and service reliability.

To perform properly ferrite testing, both a minimum material thickness and a minimum specimen size are required. Test results are interpreted in accordance with current specifications and/or customer requirements. Reports issued are accompanied when necessary by drawings to identify locations tested.

Southern Inspection applied Ferrite Testing to inspect:

1. Austenitic stainless steel/Duplex stainless steels

Welds (tubing, etc.)
Normal construction steel with Austenitic chrome alloy steel welded cladding (Ex. Boilers, vessels, etc.)

2. Weldments, Castings, Forgings, Weld Overlays, Wrought materials

3. Weld materials

Butt/fillet welds
Category A-D welds
Stainless weld overlays on non-ferrous interfaces

4. In-service and in-construction components

ADVANTAGES

Rapid and accurate analysis
Highly portable digital technology
Variable calibration in both Ferrite Number (FN) and % Ferrite (FN) using AWS Standards
Testing instrument meets all requirements of ANSI/AWS A4.2 and DIN EN ISO 8249
Calibration is traceable to internationally approved IIW secondary calibration standards

LIMITATIONS

Not recommended where the material is at temperatures greater than approximately 125°F
Surface preparation is very important for result accuracy
Both a minimum material thickness and a minimum specimen size are required
Shape of the specimen may have a negative effect on the results obtained. Correction calculations can be performed in some instances.

Navigation

Positive Material Identification (PMI)

Hardness Testing

Corrosion

Microetch

Ferrite Testing

Chemical Analysis