At present, the grate material of sintering machine trolley used by iron and steel enterprises has the characteristics of various types, large consumption, and short service life. Therefore, the study of the chemical composition, structural properties and failure process of cast iron materials used in grate bars is of great significance for reducing production costs and improving production efficiency of iron and steel enterprises.

grate of sintering machine

1. Working conditions and failure process of sintering machine trolley grate bars.

The sintering machine trolley runs under cold-hot-cold working conditions, and the trolley grate strips have been subjected to such repeated alternating effects of cold and heat for a long time, and it is prone to high temperature oxidation. In addition, in the sintering process of iron ore, the complex chemical composition and chemical reaction in the sintering raw materials make the sintering flue gas contain a lot of corrosive gases such as CO, CO2, and SO2, which will inevitably cause serious high temperature to the trolley grate.

Under such working conditions, the surface layer of the trolley grate bar is prone to oxidation and fall off, and impact and abrasion will also occur during the loading and unloading of sintered raw materials and sintered ore, which will eventually increase the gap between the trolley grate bars. According to on-site production practice, when the gap between the trolley grate bars exceeds 8mm, the grate bars can no longer be used, and the replacement requirements are met. In addition, when the sintering machine is working with the base material, the low-melting point substances will adhere to the grate bar at high temperature, resulting in the narrowing of the grate bar gap and poor ventilation, and finally it must be replaced. During the sintering process, the grate bar is worn and impacted by the sinter, coupled with the effects of high temperature and stress, will creep, and will fail when the creep exceeds a certain size.

According to the analysis of the working conditions of the sintering machine trolley, the grate bars need to have excellent heat resistance, oxidation resistance, high strength, toughness and wear resistance, and other comprehensive properties. High demands.

2. Current status of development and application of cast iron materials for trolleys

The higher the output of sinter, the greater the demand for grate bars. As a vulnerable part of the sintering machine trolley, the quality and performance of the grate directly affect the production cost of the sintering machine and the operation rate of the sintering machine equipment. At present, the annual output of sinter in my country is more than 800 million tons, and the annual consumption of trolley grate bars is more than 100,000 tons.

Therefore, the material of the grate is a problem that cannot be ignored in the entire sintering production. The materials used in the grate bars of the sintering machine trolley in my country have experienced ordinary cast iron, heat-resistant ductile iron, high chromium alloy cast iron and multi-alloyed high chromium alloy cast iron materials.

Jinggong Measuring Tools Producing Co., Ltd is specializing in manufacturing and exporting all kinds of cast iron products，especially for cast iron floor plates, cast iron surface plates, cast iron clamping plates, cast iron angle plates, cast iron box table and other machine tool castings. Our engineering enables us to design the cast iron plates and tables according to DIN Standards, Indian Standards and Chinese Standards, machining by CNC machine tools and install in the world market.