CZ238092A3 - Cast iron resistant to abrasive wear - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wear abrasive-resistant cast iron comprising 1.8 to 3.5 wt. % carbon, 0.4 to 1.2 wt.

% manganese, 0.3 to 0.8 wt. % silicon, 20 to 29 wt. % of chromium, 0.01 to 0.05 wt. % phosphorus, 0.01 to 0.03 wt. open,

A. <

* which is especially suitable for dynamically stressed machine parts subjected to intensive abrasive wear.

BACKGROUND OF THE INVENTION

Currently-for dynamically stressed · scučásti _/ such as strips of impact crushers, jaw crushers and grinding board mills, which are subjected to intensive abrazívnírau wear during crushing ore, coal, aggregate, salt and the like utilize low and medium alloyed cast steel with structure of tempered martensite. Mechanical properties such as strength and impact strength. range of high values, but values of relative abrasive wear resistance,,? ψ max are low.

Furthermore, chromium-alloyed steels and eutectic steels and cast iron having a composition of 1.2 to 3.5% by weight are known. % carbon, 15 to 31 wt. chromium with high value of relative resistance i *

.. against abrasive wear ψ®2.7 to 3.6. The disadvantage of these materials is the high brittleness and low value of the material.

_O natosti reaching maximum 3 ď.cm ^£ in a hardened and tempered condition. The crystallization of the casting results in the formation of a transcrystallization zone in which cracks occur during hardening. Under dynamic loading of the castings, the cracks propagate until premature edging occurs. The above-mentioned alloys of the invention

they are now susceptible to the formation of central porosity, from which cracks propagate and the edges of the stressed parts occur.

SUMMARY OF THE INVENTION

Above.

(The above mentioned disadvantages are abrasive wear-resistant cast iron containing 1.8 to 1.5 bar)

3.5 wt. % carbon, 0.4 to 1.2 wt. % manganese, 0.3 to 0.8 wt. 20 to 29 wt. 0.01 to 0.05 wt.%, phosphorus and 0.01 to 0.03 wt. sulfur according to the invention. Its essence is that the cast iron further contains 0.05 to 0.2% by weight. % vanadium, 0.01 to 0.1 wt. % zirconium 0.002 to 0.006 wt. % boron and 0.01 to 0.1 wt. of aluminum. .

Furthermore, the cast iron further preferably comprises 0.3 to 2.0 wt. % molybdenum and / or 0.3 to 1.0 wt. % of nickel) to suppress the formation of perlite during quenching of the walled castings.

largely removed with ¹ '

The advantage of such cast iron is the suppression of the transcrystallization zone during crystallization and of the central porosity that causes local fragility of the casting. Intensive heterogeneous nucleation of the primary structure occurs in the first phase, resulting in a refinement of the primary grain of the lamellar eutectic. In the cast state, the metal matrix consists of austenite and a tough type of isartensite consisting of needles with a substructure of dislocation. When cast iron is cooled slowly in sand form, martensite is dissolved after casting. The impact toughness is 6-11 µm and the hardness is 46-53 µC.

z - zfv Urn! f> c m; · O .. cd o! The advantage is that the service life of the components is higher and that r 2,7 2.7 to 3.1 is advantageous. Pa 1 š í zu

3.3

L · Π hardness for wider use. , so.

The cast iron according to the invention can be hardened. After quenching into martensite and cocuštění secondary hardness, to increase the value r.ciriěrna fopotře ber »UPN ^{- nn} '''

- J>

to 61 HRC and impact strength to 5.0 to 6.5 .mu.m

DETAILED DESCRIPTION OF THE INVENTION

The invention is described in more detail by way of examples of a specific embodiment.

Example 1

Armor for crushers for crushing aggregates, tulle made of cast iron with the following chemical composition:

£% h t t

uh 1 ík r> Ό. , 60 manganese Kn 0 , 57 silicon Si 0 , 60 phosphorus ΤΊ r 0 , 028 sulfur Q O , 021 c h r o m Steed , 70 moly bděn Op 0 , 50 n i k 1 Fri 0 , Λ6 · vanadium in 0 , 10 · z i rkcnuM Zr 0 r ·. r ', , b o r (B) 0 , 004 aluminium A.l 0 , 038

The hardness of cast iron of this chemical composition was cast

Seynatcs t _ 6.9 _ .. J ,. _r cm3 proportional jf / 5 / resistance to abrasive cp-c friction ψί 2.9. Pc heat treatment J ^ 0‘50 ° C, 1 h, oil, tempering 515 ° C, 5 h, air cooling was 56 HRC hardness. toughness of 5.8 -J.crr- and pc.m.abrasion resistance

wear and tear

When grinding the aggregate, it only throws a slight wear on the armor of the crusher.

Example 2

The armor of a daughter who had crushers for crushing aggregates as follows:

tulle made of lithium-

% wt. AND carbon C 3.00 manganese Mn 0.67 silicon Si 0.37 phosphorus p 0,023 sulfur WITH 0,023 c th Cr 24.60 vanadium IN 0.05 of i rkon / tfhi Zr. 0.08 boron T ^. 0.004 aluminium Al 0.015 moly bděn Mo 1, 83 M echanical features of this cast iron ladu 1. When grinding kameni va occurs at this

were similar to cast iron only to slight wear of shredder armor.

Jrůmys lo vě., - usability- ₌ . _a , _s ..

The cast iron according to the invention finds particular application in the stone industry for dynamically stressed machine parts subjected to intensive abrasive wear.

Claims (1)

'---------- ^{_ 1} ''1; The wear-resistant cast iron has a wear content of 1.8 to 3.5% by weight. % carbon, 0.4 to 1.2 wt. % manganese, 0.3 to 0.8 wt. % silicon, 20 to 29 wt. % of chromium, 0.01 to 0.05 wt. ? ' % phosphorus, 0.01 to 0.03 wt. sulfur, characterized by s e by that the content is 0.05 to 0.2 wt. vanadium, 0.01 and ž 0.1 % wt. zircon! ^ 0, 002 to 0.006 wt boron and 0.01 to 0.1 % wt. of aluminum. 2. He was on you by Maro 1 , I'll mark her it is three m, that content is 0.3 to 2.0% wt. molybdenum and / or 0.3 to 1, 0% wt. nickel.