SU621786A1 - Steel - Google Patents

Description

one

This invention relates to the metallurgy of ferrous metals, in particular, to manganese steels used for the manufacture of parts operating under conditions of impact-abrasive wear, for example, tractor tracks, wear parts of crushing equipment, drags, excavators and other machines.

Closest to the invention is steel containing, by weight. %:

Carbon 0.8-1.4

Silicon0.5-1.5

Manganese about 10

ChromeDo 8

Iron Else I.

A disadvantage of the known steel is low wear resistance under abrasive wear.

The purpose of the invention is to increase the wear resistance of steel with abrasive wear.

This is achieved by the fact that the proposed steel contains components in the following ratio, weight. %:

Carbon1.0-1.3

Manganese6.0-8.0

Chrome 1.5-2.5

Silicon1,1-1,5

IronErest

The ratio of manganese to silicon does not exceed 6.

The proposed steel may have impurities, weight. %;

Sulfur0,002-0,05

Phosphorus 0.05-0.1

The structure of this steel after casting and heat treatment consists of an austenitic matrix and carbides. Low content:

manganese in steel provides a metastable matrix. Such a matrix provides hardening of the surface layers of steel in the process of wear, both due to the hardening of the metastable austenite, and due to its phase transformations into a high-hard and wear-resistant c-phase called martensitol deformation, and the more complete the more carbon and less manganese is in it. The microhardness of the surface steel layers during the wear process increases from H 306 to H 950, and the amount of deformation martensite formed during the wear process is 30%. This hardening and causes an increase in wear resistance of steel. The relative wear resistance of the steel is 1.45.

In addition, the ratio of the constituent components of the steel reduces the stability of austenite against isothermal decomposition, and the ratio of manganese content to silicon content less than 6 increases the activity of carbon in austenite. This increases the rate of austenite decomposition and carbidization, which increases the amount of the carbide phase, contributes to the phase recrystallization of austenite and thereby provides a fine-grained austenitic-carbide structure with a uniform distribution of carbides in the unstable austenitic matrix. This increases wear resistance as well as strength, ductility and toughness of steel.

The composition of the proposed steel is given in table. 1, and their properties in table. 2

Table 1

table 2