SU1004482A1 - Austenite steel - Google Patents

Description

The invention relates to metallurgy, in particular, to austenitic steels and can be used in metallurgical mining and other areas of the scale for the manufacture of fast-wearing steel parts of sintering machines, crushing and grinding equipment and other parts operating under conditions of contact-shock loading, friction wear at temperatures up to 40r-450 s.

Nowadays, steel 110G13L tl is widely used for this type of cast parts.

However, well-known steel often does not meet modern requirements due to the insufficiently high wear resistance of this steel at temperatures of heating the surface of parts above ZOO.C.

The technical essence and the achieved effect closest to the proposed steel is austenitic steel .pj, containing, wt.%:

Carbon 0.28-0.32

Manganese 9.0 -10.0. Chrome9.0 -10.0

Silicon To 0.5

Iron Else

The main disadvantages of steel are relatively low ductility and toughness. Under operating conditions, this often contributes to the brittle fracture of cast parts.

The purpose of the invention is to improve the plastics, impact toughness, wear resistance under conditions of heating the surface of parts up to 400-500 ° C, as well as in friction with increased slip rates.

To achieve this goal, the described austenitic steel containing carbon, manganese, chromium, silicon, iron further contains molybdenum and vanadium in the following ratio of components, wt.%:

Carbon, 0.35-0.50

20 Manganese 7.1 -8.0 Chrome 10.5-12.01

Silicon 0.35-0.50 Vanadium .- 0.12-0.29 Moss hbden 0.25-0.38

25 Iron Else Introduction to steel in addition to molybdenum prototype contributes to the improvement of ductility and impact strength of cast steel. In addition, the alloying of steel with molybdenum prevents the precipitation of carbides along the grain boundaries during slow cooling of parts from high temperatures, which is important for improving the quality of heat treatment of massive parts.

The introduction of vanadium additionally contributes to the improvement of wear resistance and heat resistance of steel.

In tab. 1 shows the chemical composition of steel.

Ingots weighing 10–12 kg are melted in an induction furnace in air. The content of impurities - sulfur and phosphorus in all heats does not exceed 0.05%.

The ingots are subjected to heat treatment in the following mode: heating to 1100 ° C, holding for 6 hours, cooling with a furnace to room temperature.

Cut ingots from 12 ingots to 12-60 mm and 20V70 x X 7 mm are cut from ingots. The billets are quenched from 11501170 ° C to water, after which samples are made from them for mechanical and wear tests. The structure of all steels after this heat treatment is austenitic. The grain size of austenite corresponds to 2-4 points. Steel hardness is HB 250-270 kgf / mm.

In tab. 2 presents the results of mechanical testing and testing for abrasive wear resistance of austenitic steels.

In tab. 3 shows the influence of the slip rate on the wear rate of austenitic steels.

In tab. Figure 4 shows the effect of temperature testing on the wear of austenitic steels.

The wear resistance of the proposed steel under friction with increased and slip speeds of 3.0 and 4.5 m-s, when there is an intensive frictional heating of the sample surface, as well as with external heating of the samples up to 300 and 400.C several times (5-8J

5 exceeds the wear resistance of steel 110G13L and 2-4 times - the wear resistance of the prototype.

The increased wear resistance of the proposed steel is associated with the formation in them during friction of C-martensite deformation, which has considerable strength and heat resistance (resistance against tempering). Doping 25 austenite with molybdenum and vanadium provides it with greater (compared to the prototype) heat resistance, which causes an additional increase in wear resistance 3Q of the proposed steel compositions under conditions of heating the friction surface to 300-400 ° C.

Table 1

0.2810.0

0,357,10

0.467.46

0.508.0, The chemical composition of steel corresponds to steel.

0.30

10,500,35

0.12

0.25

11,180,22

0.21

0.32

12,010,50

0.38

0,29 chemical composition known

1 -35.0. 72,0151610.5

38,080,516,018,512,0

36,584,020,0-19,015,4

38,585,021,020,016,0

45.2

16.5

20.0

110G13L

1,8,1,4

0.5

0.6

table 2

1.70 1.85 1.82 1.92

Table 3

68.5

80.0

22.0

13.5

7,8

15.2

20.0

5.3

6.9

14.3

25.0

7.1.

1.2

4.2

3.9

: 0.8

0.7

0.5

0.7

o

0.9

1.0

s-.

1004482

Claims (2)

1. GOST 2176-77. Steel 110G13L. 2. USSR author's certificate 153291, cl. C 22 C 38/38, 1963.