Chemical Composition Of Inclusions Research Articles

Study of the nature of non-metallic inclusions in samples of aluminum and silicon killed low carbon steels, collected in the refining treatment and continuous casting stages

The amount, distribution, size and chemical composition of non-metallic inclusions have a direct influence on steel properties. By controlling size and chemical composition of these inclusions, it is possible to get a product with good quality. The identification of the nature and the control of inclusion formation are very important for steel cleanness. The behavior of these inclusions is predictable, in some extent, by the determination of the chemical composition of non-metallic phases that form such inclusions. With the objective of studying the chemical composition, the size and the distribution of such inclusions, samples of aluminum and silicon killed low carbon steels were collected in a national steel industry in the secondary refining and continuous casting stages. These samples were analyzed in the scanning electron microscope (SEM) coupled to an energy dispersive analysis system (EDS). From the results, it was possible to evaluate the nature of inclusions and to analyze the effectiveness of the refining process in the reduction of the number and area fraction of the inclusions. It was also possible to verify that the inclusions that remained after treatment, are less damage both to the steel properties as to the continuous casting process (clogging of the submerged valve).

Avaliação do tamanho, da morfologia e da composição química de inclusões não metálicas em aço baixo carbono desoxidado ao alumínio

A presença de inclusões não metálicas endógenas e exógenas prejudica a lingotabilidade e as propriedades mecânicas dos aços. A busca contínua pelo controle da quantidade, do tamanho, da morfologia e da composição química de inclusões não metálicas tem sido tema de estudos nas últimas décadas, em especial durante o processo de refino secundário dos aços. Através do controle, principalmente, do tamanho e da composição química das inclusões, é possível obter um produto final de boa qualidade. A identificação da natureza e o controle da formação de inclusões são de suma importância para a obtenção de aços limpos. Este trabalho tem como objetivo fazer uma investigação de inclusões não metálicas em aço de baixo teor de carbono(SAE 1015), desoxidado ao alumínio, através de um método de dissolução parcial e total da matriz metálica e posterior análise ao Microscópio Eletrônico de Varredura (MEV), acoplado a um sistema de análise por energia dispersiva (EDS), permitindo uma visualização do tamanho, da forma e da composição química das inclusões com maior precisão, sem interferência da matriz ferrítica.

アルミナるつぼで溶解した高純度鉄中に観察される介在物の組成

アルミナるつぼで溶解した高純度鉄中に観察される介在物の組成

Sur les roches pyroclastiques au Nord du Dacht-e-Nawar (Afghanistan); les quartz et leurs inclusions vitreuses

Abstract Quaternary, chemical composition of inclusions, magmatic origin

軟鋼熔着金属中の非金属介在物の形態と組成(第3報)

In the 1st and 2nd reports, the authors analyzed chemically the non-metallic inclusions in weld metals and observed these shapes under optical and electron microscope. From these experiments, authors confirmed the mechanisum of the formation process of inclusion particles in molten weld metal.In this report, inclusions were separated as residue from alcoholic iodine solution and analyzed these crystal formes using x-ray diffractometer. In the previous report, inclusions were analyzed using electron diffraction method but identification was difficult. The results of x-ray diffraction supplied the previous results and confirmed the relation between crystal forms, chemical compositions of inclusions and chemical compositions of weld metals.Inclusions in weld metals were consist of the majority of amorphous and a part of crystal structure. 2MnO⋅SiO2 was found in ilmenite type A, MnO-SiO2 and 2MnO⋅SiO2 was found in ilmenite type B and SiO2 was found in low hydrogen type.The chemical compositions of weld metals were as follows : ilmenite type A was Si poor, low hydrogen type was Si rich and ilmenite type B was most popular compositions of Mn and Si in weld metal. The chemical compositions of inclusions in all these weld metals were consist of MnO and SiO2 but SiO2 contents in these inclusions were varied as follows : 33% in ilmenite type A, 46% in ilmenite type B and 49% in low hydrogen type. From these results and phase diagram of MnO-SiO2 system or [O]-[Mn]-[Si] in molten steel (by Kdrber and Oelsen), the shapes of inclusion particles and the crystal forms of inclusions in weld metals could be estimated. These estimations were supported with the results of the experiments in this and previous reports.Second experiment in this report, inclusions were separated and analyzed using x-ray diffractometer in the heat treated weld metals at 900°C and 1400°C. The crystal forms of inclusions in these weld metals were changed by means of heat treatments as follows : In the weld metals heated at higher temperature than the melting point of inclusions, inclusions were changed amorphous structure. On the other hand, in the weld metals heated at lower temperature than the melting point of inclusions, the crystal parts of inclusions were increased than the as-welded state.

軟鋼熔着金属中の非金属介在物の形態と組成(第1報)

In the 1st and 2nd reports, the authors analyzed chemically the non-metallic inclusions in weld metals and observed these shapes under optical and electron microscope. From these experiments, authors confirmed the mechanisum of the formation process of inclusion particles in molten weld metal.In this report, inclusions were separated as residue from alcoholic iodine solution and analyzed these crystal formes using x-ray diffractometer. In the previous report, inclusions were analyzed using electron diffraction method but identification was difficult. The results of x-ray diffraction supplied the previous results and confirmed the relation between crystal forms, chemical compositions of inclusions and chemical compositions of weld metals.Inclusions in weld metals were consist of the majority of amorphous and a part of crystal structure. 2MnO⋅SiO2 was found in ilmenite type A, MnO-SiO2 and 2MnO⋅SiO2 was found in ilmenite type B and SiO2 was found in low hydrogen type.The chemical compositions of weld metals were as follows : ilmenite type A was Si poor, low hydrogen type was Si rich and ilmenite type B was most popular compositions of Mn and Si in weld metal. The chemical compositions of inclusions in all these weld metals were consist of MnO and SiO2 but SiO2 contents in these inclusions were varied as follows : 33% in ilmenite type A, 46% in ilmenite type B and 49% in low hydrogen type. From these results and phase diagram of MnO-SiO2 system or [O]-[Mn]-[Si] in molten steel (by Kdrber and Oelsen), the shapes of inclusion particles and the crystal forms of inclusions in weld metals could be estimated. These estimations were supported with the results of the experiments in this and previous reports.Second experiment in this report, inclusions were separated and analyzed using x-ray diffractometer in the heat treated weld metals at 900°C and 1400°C. The crystal forms of inclusions in these weld metals were changed by means of heat treatments as follows : In the weld metals heated at higher temperature than the melting point of inclusions, inclusions were changed amorphous structure. On the other hand, in the weld metals heated at lower temperature than the melting point of inclusions, the crystal parts of inclusions were increased than the as-welded state.