Steel chemical analysis: the identity of the material

Chemical analysis makes it possible to verify that the material produced falls within the expected compositional limits:

• technical standards
• customer specifications

👉 In other words:
it defines the very identity of the steel.

Each element present in the alloy contributes to determining the behavior of the material during:

• machining
• heat treatments
• final use

The determination of chemical composition is carried out using advanced analytical techniques.

👉 Steel mills mainly use:

• spectrometric methods
• fast and high-precision analyses

These technologies make it possible to carry out checks:

• during the production process
• in final laboratory inspections

Among the most widely used techniques for measuring chemical composition is optical emission spectrometry, OES.

👉 How it works:

• a metal sample is subjected to an electrical discharge
• the atoms become excited
• they emit light with specific wavelengths
• the spectrometer detects these emissions

👉 The result:

• identification of the elements
• precise measurement of concentrations

✔ simultaneous analysis of multiple elements
✔ possibility of determining carbon content
✔ fast times
✔ high precision

Before analysis, the sample must be properly prepared.

👉 The surface is processed in order to:

• eliminate oxides
• remove contamination
• ensure uniformity

✔ This phase is essential to avoid measurement errors.

Compared to the portable XRF analyzer available at BA, OES analysis does, however, have some disadvantages.

One of the main ones is the need to have a small-sized sample suitable for placement inside the analysis instrument. This makes direct inspection of large manufactured parts or already installed components more complex, for which it is often necessary to first take a sample from the material.

OES analysis is also a partially destructive test, since during the inspection a spark is generated on the surface of the material, which may leave a small mark at the analysis point.

To obtain reliable results, more accurate surface preparation is generally required, through sanding or grinding.

👉 In summary:

✔ need to use small-sized samples suitable for analysis
✔ difficulty in directly analyzing large manufactured parts or installed components
✔ need, in many cases, to take a sample from the part to be inspected
✔ partially destructive test

The results of the chemical analysis are reported in the steel certificate 3.1.

👉 This document:

• certifies the conformity of the material
• guarantees lot traceability

👉 It allows the customer to verify that:

• the material complies with the specifications
• it is suitable for the intended application

In the BA Bonomi Acciai laboratory, the chemical analysis of steel is carried out internally, guaranteeing fast, precise and reliable quality control.

The company is equipped with a portable Niton Analyzer XL2 Gold XRF analyzer, a technologically advanced instrument that makes it possible to accurately identify and verify the chemical composition of metallic materials.

Thanks to X-ray fluorescence technology, XRF, it is possible to carry out immediate checks on the alloying elements present in the steel, ensuring compliance with the required specifications and reference quality standards.

The chemical analysis of steel is carried out in different contexts, with the aim of guaranteeing the conformity and quality of the material.

Within the BA laboratory, the check is performed on a sample basis during goods acceptance, to verify the conformity of the material received and compare its chemical composition with what is reported in the certificate 3.1.

The analysis can also be carried out upon specific customer request, for example in the presence of doubts regarding materials present in their own warehouse.

It is also used in the event of non-conformity, to investigate and verify the characteristics of the material, or as technical support for reverse engineering activities.

Sample preparation for chemical analysis using an XRF analyzer is extremely simple and fast.

One of the main advantages of this technology is in fact the possibility of carrying out non-destructive tests, without altering or damaging the material being analyzed.

The analysis can also be carried out directly on large manufactured parts, without the need to take samples to be sent to the laboratory.

Before the inspection, it is sufficient to clean the surface of any traces of:

• dirt
• oxidation
• oils present on the material

In some cases, light surface sanding may be necessary in order to ensure an even more accurate reading of the chemical composition.

Chemical analysis performed using an XRF analyzer makes it possible to detect most of the elements present in steels and metal alloys, allowing the composition of the material and conformity with the required specifications to be quickly verified.

Through this technology, it is possible to identify and check the most common alloying elements, such as:

• chromium
• nickel
• molybdenum
• manganese
• titanium
• vanadium
• copper
• many other elements

The only element that normally cannot be detected with a standard portable XRF analyzer is carbon.

This limitation is linked to the very physics of X-ray fluorescence technology: carbon, being a very light element and characterized by a low atomic number, emits energy signals that are too weak and are easily absorbed by the air or by the material itself before reaching the instrument detector.

The results of the chemical analysis are compared with different technical references, depending on the needs of the inspection and the customer’s requirements.

The main references include:

• certificate 3.1
• reference standards
• technical data sheets
• customer specifications
• applicable quality standards

This comparison makes it possible to verify whether the detected composition is consistent with the declared material and with the intended application.

The possibility of carrying out chemical analysis of materials internally represents an important added value for BA customers.

Having an immediate and direct check available makes it possible to:

• reduce verification times
• ensure faster responses
• act promptly in case of doubts
• manage additional checks or non-conformities

Thanks to the use of the portable XRF analyzer, BA can carry out fast and non-destructive checks directly on materials or components, without the need to rely on external laboratories or invasive sampling.

This translates into greater operational efficiency and concrete technical support for the customer.

Internal control also makes it possible to increase the level of reliability and traceability of the materials supplied, offering an additional guarantee tool on the conformity of the alloys with respect to the required specifications, certificates and reference regulations.

For the customer, this means being able to count on a qualified technical partner, capable of providing fast, competent and quality-oriented support throughout all stages of the supply process.

Chemical composition is not just data.

👉 It is what determines:

• the behavior of the material
• final performance
• the overall quality of the steel

An error in the composition can compromise:

❌ heat treatments
❌ machinability
❌ service life

In the certificate analyzed in the previous article, chemical analysis represents the first level of control.

👉 In the next contents, we will explore:

• hardness
• impact strength
• internal checks

The chemical analysis of steel represents the starting point for understanding the quality of the material.

👉 It is what defines the identity of the alloy.
👉 And it is the basis on which all subsequent performance is built.

Understanding it means truly reading steel.