In industry, civil engineering or architecture, the choice of the material composition of a metal part is of utmost importance when analyzing the characteristics that each particular part demands.
For this reason, the materials in our forged flanges are thoroughly verified and tested in our laboratories. Only in this way can we precisely identify the exact strength and toughness of the materials used.
What is an impact test?
Impact tests are one of the most widely used resources for analyzing the physical characteristics of a material in engineering. This type of test is used to study the toughness of a material, i.e., to measure its ability to withstand an impact before it breaks.
There are two main methods that are commonly used to conduct an impact test: the Charpy method and the Izod method. Although both tests measure the toughness of a material using a Charpy pendulum (a tool named after a well-known French engineer of the early 20th century), the Izod method differs in the geometrical details of the specimen involved in the measurement process.
An impact test pendulum is designed to strike the metal specimen of the material being studied. In both methods, the pendulum falls from an initial height and strikes the specimen with force until it breaks. At the time of impact, the pendulum loses energy, and this energy is absorbed by the specimen as it fragments. Thus, the amount of energy absorbed by the specimen will yield the point of fracture of the material. In other words, there is a difference between a specimen that absorbs three joules versus five joules of energy before fracturing, and that result is indicative of a higher or lower toughness.
In the Izod method, a square-shaped (10×10 mm) specimen is broken using three notches located on different faces. The test is completed by repeating the procedure two more times and calculating the average of the three results.
These tests show us the resilience of the material. The main difference between the Izod method and the Charpy method lies in the design and configuration of the specimen used in measurement. Both impact tests are used to analyze the toughness of a material, but the way the two tests are performed is slightly different.
A105N is one of the most widely used materials for forged flanges. It is a type of carbon steel named according to the criteria of ASTM, the chief international standards body in materials engineering.
A105N flanges are most commonly used in Oil & Gas infrastructure designs. These designs are regulated by different ASME design standards such as ASME B31.3 which applies to piping designs for all fluids. This particular standard indicates that A105N can be used in piping designs that operate at temperatures as low as -29°C without being tested, which makes it important to know the material’s toughness.
Impact tests on A105N are therefore useful to find out exactly what structural arrangements this type of steel flange can be used in without breaking. To give you an idea, industrial pipelines where forged flanges are used commonly undergo temperature changes capable of causing sudden fractures related to the toughness of the material, so it is extremely important to know the point of fracture of the forged flange you are using.
In sum, forged A105N flanges are used in industrial pipelines, especially in oil refineries. In the context of these uses it is very important to conduct all the necessary impact tests to ascertain the exact limits in terms of ductility and toughness of the material.