SU729273A1 - Cast iron - Google Patents

Description

one

The invention relates to the field of metallurgy, in particular to cast iron, working under conditions of abrasive wear and can be used for parts of shot blasting equipment.

Known cast iron l of the following composition, wt.%;

Carbon2,3-2,8

Kremniydo 1,5

Manganese-0.2-0.8

Chrome-17.0-21.0

Boron (titanium) 0.1-0.3

Iron Steel,

Such a cast iron after heat treatment (heating to 950 C, cooling in air) has the TE hardness HRC 53-6О, tensile strength6 g 5О-55 kg / mm.

The disadvantage of such a cast iron is its low durability under conditions of abrasive-erosive wear.

The purpose of the invention is to increase the wear resistance of the cast iron

This is achieved by the fact that the iron additionally contains molybdenum in the following ratio of components, wt.%:

1.8-2.2

Carbon 3.5-6.0 Silicon 0.2-0.8 Manganese 16.0-21.0 Chromium

Component selected from the group containing boron and ThiOD-0, 3 tan

0 0.5-1.5

Molybdenum X Selezo Else

The increased value of durability under conditions of abrasive erosion provides

15 with a carbon content close to eutectic. With an increase (carbon content of over 2.2%, the toughness of the material is significantly reduced, and as a result, the durability decreases

20 details. When the carbon content is less than 1.8%, the wear resistance of the material decreases due to a decrease in the number of strengthening media. 3 The amount of manganese is extremely high in iron smelting conditions, since, according to research, manganese is not an effective element that affects the durability of parts. When the chromium content is below 16%, the durability of the material decreases with abrasive-corrosion resistance due to the formation of cement type carbides with lower wear resistance. By increasing the chromium content above 21, the durability is reduced due to the appearance of brittle primary carbides in the structure. The silicon content below 3.5% does not in any way affect the wear resistance of the alloy. At 3.5-b, O% silicon, self-sustaining silicon carbide appears in the cast iron structure, its amount and dispersion increase, with increasing silicon content in the alloy. Chromium carbides are also crushed. An increase in the silicon content of 6.0% leads to a strong embrittlement of the alloy and, as a result, to a decrease in toughness and wear resistance. The introduction of molybdenum in an amount of up to 0.5% does not significantly affect the wear resistance of the alloy. When the content of MapibDena O is 5-1.5%, the wear resistance of the alloy increases due to the fact that molybdenum, dissolved in chromium carbides, contributes to an increase in the hardness of these carbides. In addition, molybdenum additives milled grain somewhat. 3 The addition of molybdenum of more than 1.5% leads to the formation of stable austenite instead of the metastable austenite required for wear resistance. Due to this, the wear resistance of the cast iron is reduced. Under the conditions of the pilot production of the IPL of the Academy of Sciences of the Ukrainian SSR, cast iron was produced in various versions, as well as cast iron in accordance with ed. St. № 195118 (table. № 1). The prototypes and shot-blasting blades were cast and their comparative tests were carried out on industrial shot-blasting plants: the features of the microstructure were also investigated. Example. The smelting of the proposed and well-known cast irons was carried out in an IGP-1.02 furnace with the main lining, the same materials were used as charge materials. The compositions of cast iron are given in table. 1. Samples of cast iron were tested on the installations of abrasive erosion, where quartz sand was used as an abrasive material. Research data are shown in Table. 2. Research results indicate that the proposed cast iron has a higher wear resistance, providing it with an increase in the efficiency of parts by 2 times. The resistance of the pig from the proposed cast iron is 120 hours. Table 1

 Test time f- 4 h Load P 4,15 kg

table 2

Claims (1)

Claim Cast iron containing carbon, silicon, manganese, chromium, iron and a component selected from the group consisting of boron and titanium, characterized in that, in order to increase wear resistance, it additionally contains molybdenum in the following ratio of components, weight% „ Carbon 1.8-2.2 Silicon 3.5-6.0 Manganese Chromium A component selected from the group consisting of boron and titanium Molybdenum Iron 0.2-0.8 16.0-21.0 0, .1-0, .3 0.5-1.5 Rest