CS204589B1 - Menganese austentic steel with resistance to wear - Google Patents

Description

BACKGROUND OF THE INVENTION The present invention relates to wear-resistant manganese auetenitic steel, particularly suitable for functional parts of hammer, fan, spherical mills used for grinding and crushing heavily abrasive materials, and for other treatment machines at lower levels of dynamic strain.

Meanwhile, the most common manganese auetenitic steel containing about 1.2% by weight of carbon and 12% by weight of manganese, which is produced with the addition of 1% by weight of chromium, has been used for the grinding and treatment of abrasive materials and raw materials such as coal in mills. The main disadvantage of this steel is that at a low level of dynamic stress induced by the force effects between the grinding and the grinding elements of manganese auetenitic steel, the surface layer of this steel does not sufficiently reinforce and transform

Laboratory mechanical and metallographic tests revealed that the hardness of the microhardness was increased by a maximum of 10%, and the austenite microhardness was increased by 100% only in a thin layer up to 0.3 mm. discontinuous due to hard particle scoring. Manganese auetenitic steel under these conditions has low resistance to abrasive and erosive wear.

These deficiencies are eliminated by manganese auetenitic steel containing 1.0 to 1.5% by weight.

5C ··?

% 204 589 carbon, 10.0 to 15.0 wt. % manganese, 1.0 to 3.0 wt. % chromium, 0.3 to 1.5 wt. The molybdenum according to the invention, the subject matter of which is that the steel further comprises 0.81 to 1.3 wt. % silicon and 0.001 to 0.005 wt. The steel according to the invention has an increased austenite microhardness, a higher carbide content and hence an improved particle wear resistance at a lower level of dynamic stress.

The properties of the steel according to the invention are further favorably influenced by other alloys, namely 0.3 to 1.0 wt.%, Nickel, 0.01 to 0.1 wt.%. % titanium, 0.01 to 0.2 wt. % vanadium and 0.3 to 1.5 wt. copper. These elements improve the properties of the steel of the invention by adding individually or in a suitable combination with the other elements.

Compared to conventional manganese austenitic steels, the various steel variants according to the invention exhibit a significantly increased wear resistance of 20 to 50% under particle wear conditions at lower dynamic stresses. To improve the abrasion resistance of the steel, in particular by increasing the austenite strength, increasing the content of finely divided carbides, and refining the grain, the above-mentioned elements were used in the following exemplary melts.

Example 1

A melt containing 1.03 wt. % of carbon, 10.5 wt. % manganese, 0.34 wt. % molybdenum, 1.08 wt. % chromium, 0.83 wt. % silicon; and .001 wt. boron. After austenitization, wear resistance was determined on the abrasive cloth. Values of relative abrasive wear resistance were obtained. - 1.61 to 1.75, while classical manganese austenitic ooel has an abr value. »1.55 to 1.57.

Example 2

A melt having a content of 1.46% by weight was cast. % carbon, 14.4 wt. % manganese, 2.71 wt. %, 1.3 wt. % molybdenum, 1.22 wt. % silicon and 0.005 wt. boron.

After special heat treatment, abr values were reached. 1.69 to 1.86, which are relatively high values, since they are achieved on corundum abrasive cloths, while in most industrial grinding cases, the hardest components are SiO ₂ particles.

Example 3

The melt according to Example 1 was cast in which the alloy was further used:

a) 0.33 wt. % nickel and 0.01 wt. titanium,

b) 0.01 wt. % vanadium and 0.32 wt. copper.

Following austenitization and testing on the abrasive cloth, the following values were found:

(a) rabr 1,63 to 1,79

b) .delta

204 S89

EXAMPLE 4 A melt according to Example 2 was cast in which an additive of the following alloy was used:

(a) 0,93% by weight, nickel, 0,093% by weight, titanium,

b) 0.19 wt.%, vanadium and 1.44 wt. copper,

Austenitization revealed these abr values.

For alternative a) - abr. 1.79 to 1.90

b) - abr, 1.75-1.91

The effect of the alloys of Examples 3 and 4 in combination on the austenitic values of steels was investigated in the melts of Examples 5 and 6.

Example 5

B _in la casting chemical composition:

Carbon - 1.2 wt%, manganese - 12.25 wt%, chromium - 1.4 wt%, silicon - 1.3 wt%, molybdenum - 0.46 wt%, boron - 0.005 wt% , titanium - 0.02 wt.%, vanadium - 0.04 wt.%, nickel - 0.62 wt.

Determined values of yield strength, strength and hardness limits:

<T * Kt - 410 MPa HB - 210-230 <r * Pt - 830 MPa HM _5Q - 550 notched toughness - 150 J

In this melting, a significantly increased microhardness of the basic austenitic mass and abr was found. = 1.75 to 1.92.

Example 6

Casting with chemical composition:

Carbon - 1.33% by weight, manganese - 11.07% by weight, chromium - 1.96% by weight, molybdenum - 0.65% by weight, silicon - 0.94% by weight, boron - 0.002% by weight % by weight, nickel - 0.36% by weight, titanium - 0.10% by weight, vanadium - 0.12% by weight, copper - 0.35% by weight

These values were found after austenitization from 1130 ° C

Kt - 430 MPa HB - 220 to 240 (J ^ Pt - 860 MPa HM50 - 570 notched toughness - 135 J

Abrasion resistance in abr. = 1.79 to 1.90

Claims (2)

1. 'wear-resistant anganese austenitic steel at a lower level of dynamic stress, containing by weight 1,0 to 1,5% of mass; % carbon, 10.0 to 15.0 wt. % manganese, 1.0 to 3.0 wt. % chromium, 0.3 to 1.5 wt. molybdenum, characterized in that it contains 0.81 to 1.3 wt. % silicon and 0.001 to 0.005 wt. boron. 2. Manganese austenitic steel according to claim 1, characterized in that it contains 0.3 to 1.0 wt. % nickel, 0.01 to 0.1 wt. % titanium, 0.01 to 0.2 wt. % vanadium, 0.3 to 1.5 wt. individually or in combination with at least two of said elements. Printed by Moravian Printing Works,