Характеристика твердості чавунних гальмових колодок залізничного транспорту

• Дата: 2023
• Автор: Сіренко, Катерина
• Формат: Стаття
• Мова: Українська
• Опубліковано: Physico-technological Institute of Metals and Alloys 2023
• Теми: чавун; литво; гальмові колодки; хімічний склад; твердість; вуглецевий еквівалент
• Онлайн доступ: https://www.metalsandcasting.com/index.php/mcu/article/view/33
• Назва журналу: Metal and Casting of Ukraine

The dependence of the hardness of these castings on the chemical composition and carbon equivalent of the cast iron from which they are made was analyzed on the example of brake pads of railway rolling stock. In the product range of foundries, brake pads for railway transport are responsible products. An indicator of the quality of cast iron used for the manufacture of brake pads is compliant with strict requirements for their structure and mechanical properties, including hardness and tensile strength. The results of research performed at the foundry of LLC “M-LIT” showed that in the area of factor space, limited by the mass fraction of chemical elements in synthetic cast iron, which is used for the manufacture of brake pads brand “M” in accordance with GOST 30249-97, their hardness and tensile strength do not correlate with the values of the carbon equivalent of the chemical composition of cast iron, calculated by different formulas. The coefficients of variation of hardness of HB brake pads were 0.084 and 0.073, respectively, according to the initial factory data of different batches of this foundry and (0.082 and 0.069) after removing errors from the sample arrays. The hardness and breaking strength of the brake pads of industrial batches produced at the LLC “M-LIT” plant did not correlate with the content of individual chemical elements or with the carbon equivalent of the cast iron from which they are made. The results of researches of dependence of hardness of cast-iron pads on their chemical composition and carbon equivalent of Ceqv of cast iron are generalized. It is shown that in the range Ceqv = (3.13...3.64) % the hardness of HB pads does not depend on the value of the carbon equivalent of the cast iron from which they are made. The analysis of data given in the literature also showed that in cast-iron castings, the carbon equivalent of which is approximately within Ceqv ~ (3.0...5.0) %, the dependence of the hardness of HB on the carbon equivalent is not clearly visible.