Структура і властивості маловуглецевих низьколегованих сталей, які містять домішки миш’яку

Опытно-промышленные испытания сортового проката сталей 10ХСНД и 15ХСНД с содержанием мышьяка 0,15% для подвижного состава железнодорожного транспорта (рамы полувагонов), балок транспортных галерей рудоперегружающего комплекса, опор и жестких поперечин железнодорожной контактной сети в период 2000 - 2005 г.г. показали высокую эксплуатационную надежность этих сталей с ожидаемым экономическим эффектом 53 250 грн.

Эксплуатационные испытания шахтной стойки из стали 20Г2АФпс, в период 2000 - 2005 г.г. в реальных условиях шахты “Южнодонбасская № 1” показали высокую надежность и долговечность, наряду с хорошей коррозионной стойкостью в шахтных водах, что облегчает демонтаж и перенос крепи. Экономический эффект от применения этой стали составил 20 936 грн.

Ключевые слова: феррит, дислокация, структура, отпускная хрупкость, вязкость, коррозия, мышьяк.

ANNOTATION

Samokhvalov G. V. The structure and properties of Low-carbon and Low-alloyed steels containing impurities of arsenic.

Thesis for Candidate's degree of Science on speciality 05.16.01 - Physical metallurgy and Heat - treatment of metals. -Pryazovskiy State Technical University, the Ministry of Education and Science of Ukraine, Mariupol, 2005.

This thesis is devoted to the research of arsenic impurity influence on physical, mechanical and technological properties, performances, corrosion resistance of Low-alloyed and Low-carbon steels. The solution of this task is given, which made it possible to change the Limited content of arsenic in steels and to give practical recommendation on field application steels expansion, containing impurities of arsenic.

It is shown experimentally by criterion of tongh-brittle change of iron-arsenic alloys and by crack of steels 16Д, 15ХСНД and 20Г2АФпс, that the introduction of AS in a-iron up to 0,4 % and to steel up to 0,19 % doesn't Lead to substantial decrease of their plasticity and ductility at the account of density dislocations inrease, subgrain grinding, dispersity pearlite rise.

For the first time temperature range of phosphorus and arsenic influence on reversible brittleness of Low-alloyed and Low-carbon steels have been experimentally determined and distinguished.

The temperature range of 525-565 ^oC is connected with intercrystalline inner absorbtion phosphorus, but 625-665 ^oC - arsenic.

With the help of statistical processing of results of mechanical testing and chemical composition of sleels it is shown, that as for the level of mechanical properties of steels 15XCHД, 14Г2 and others, melted on the basis of Kerchensky ores (steel wilt AS) and Similar marks of steels, melted on other ores (steel without AS) are practically the same, which made it possible to ground the Limited content of arsenic in steels.

The obtained results of arsenic influence on physical and mechanical properties, performancies and corrosion resistance of Low-alloyed and Low-carbon steels on the ground of general analysis and conclusion a great number of industrial experiments, as well as theoretical conclusions enabled to recommend to raise upper Limited Level of arsenic content in ДСТУ 2651-94 (GOST 380-94) and GOST 19281-89 up to 0,5% for Large section and structural shapes of carbon and Low-alloyed steel.

The industrial testings of 10XCHД and 15XCHД containing 0,15% of arsenic for rolling stock (car frame), beams of conveyer galleries of ore gantry complex, contactline supporting structure in the period of 2000-2005 showed high performance reliability of these steels with the expected economic effect 53 250 gr.

Performance testings of pit prop made of steel 20Г2AФпс in the period of 2000-2005 in real conditions ”Yuzhnodonbasskaya №1” mill showed high reliability and durability along with good corrosion resistance in colliery sewage which makers dismounting and support transfer easier.

The application of the steel gave economic effect 20 936 grivnas.

Key words: ferrite, dislocation, structure, temper brittleness, ductility, corrosion, arsenic.

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