Prakt. Met. Sonderband 46 (2014) 137
ULTRA-FAST CHARACTERIZATION OF NON-METALLIC
INCLUSIONS IN STEEL WITH SPARK-OES - PRINCIPLES AND
APPLICATION TO QUANTITATIVE SIZE DISTRIBUTION
ANALYSIS AND TO ULTRA-LOW OXYGEN DETERMINATION
J.-M. Béhlen, K. Li, R. Yellepeddi
Thermo Fisher Scientific, Ecublens, Switzerland
10 um
ABSTRACT
For many steel grades and products, control of non-metallic micro-inclusions during
production process is essential to guarantee steel cleanness and properties, and to avoid
considerable quality costs. As a production process control tool used in every steel plant,
the OES spectrometer is ideal for achieving this important task that standard inclusion
analyzers cannot perform fast enough. The Thermo Scientific™ ARL iSpark™ allows
qualitative evaluation of inclusions in term of type, composition, size (distribution) and
a number. In advanced methods it even allows quantitative size (distribution) analysis and in
10 um killed steels determination of oxygen concentration down to a few ppm. It achieves
inclusion and elemental spectrochemical analyses together in seconds, making ARL
1i- Ätzung iSpark the all-in-one instrument for optimal, economical, in-process steel quality control.
Other benefits of using the ARL iSpark OES spectrometer for inclusion analysis include
minimal investment cost and overall low cost of ownership.
hie D1 und
ebnissen: 1. INTRODUCTION
Eisen sind
vorhanden. Non-metallic inclusions are of considerable importance for the steel industry due to the
C-Diffusion dramatic influence that even small amounts of them may have on properties of the metal
ZU. (mechanical and others) or on the production process itself [1, 2]. The inclusions can have
2gierte) ge- positive effects and may increase the value of the steel, but most often inclusion signify
nd V-reiche quality problems and costs. This is true in particular for an increasing number of steel
K600 kann types used for demanding applications and industries (e.g. automotive, aerospace,
ind an der nuclear, offshore and pipeline industries). Therefore for many companies, a main objective
gänge bzw. is to keep the critical inclusions under very tight control during the production.
schiedlicher
stättenscher The modern reference for inclusion analysis is the SEM/EDX (scanning electron
eile wurden microscope coupled with energy dispersive X-ray fluorescence spectroscopy). It takes
kterisiert. typically several hours, including sample preparation and interpretation. by far too long to
be applicable for production control.
The ARL iSpark - like its predecessor, the ARL 4460 - offers extremely fast and
economical methods, known as Spark-DAT (Spark Data Analysis and Treatment) methods
which are able to provide inclusion information even during the steel production process.
falz, 1999. The methods use the principle of Single Spark Acquisition (SSA), where signals from the
I~ individual “single sparks” are not summed as in conventional OES acquisition, but
processed with special algorithms. Spark-DAT is sometimes referred to as OES-PDA.
