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Changes in the Microstructure and Abrasion Resistance of Tool Cast Steel after the Formation of Titanium Carbides in the Alloy Matrix

Tęcza Grzegorz

Archives of Foundry Engineering

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2023

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Vol. 23, iss. 4

173--180

EN

Cast martensitic alloy steel is used for the production of parts and components of machines operating under conditions of abrasive wear. One of the most popular grades is cast steel GX70CrMnSiNiMo2 steel, which is used in many industries, but primarily in the mining and material processing sectors for rings and balls operating in the grinding sets of coal mills. To improve the abrasion resistance of cast alloy tool steel, primary titanium carbides were produced in the metallurgical process by increasing the carbon content to 1.78 wt.% and adding 5.00 wt.% of titanium to test castings. After alloy solidification, the result was the formation of a microstructure consisting of a martensitic matrix with areas of residual austenite and primary titanium carbides evenly distributed in this matrix. The measured as-cast hardness of the samples was 660HV and it increased to as much as 800HV after heat treatment. The abrasion resistance of the sample hardened in a 15% polymer solution increased at least three times compared to the reference sample after quenching and tempering.

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Changes in Abrasive Wear Resistance During Miller Test of Cr-Ni Cast Steel with Ti Carbides Formed in the Alloy Matrix

Tęcza G.

Archives of Foundry Engineering

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2021

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Vol. 21, iss. 4

110--115

EN

Austenitic chromium-nickel cast steel is used for the production of machine parts and components operating under corrosive conditions combined with abrasive wear. One of the most popular grades is the GX2CrNi18-9 grade, which is used in many industries, and mainly in the chemical, food and mining industries for tanks, feeders, screws and pumps. To improve the abrasion resistance of chromium-nickel cast steel, primary titanium carbides were produced in the metallurgical process by increasing the carbon content and adding titanium, which after alloy solidification yielded the test castings with the microstructure consisting of an austenitic matrix and primary carbides evenly distributed in this matrix. The measured hardness of the samples in both as-cast conditions and after solution heat treatment was from 300 to 330HV0.02 and was higher by about 40-70 units compared to the reference GX2CrNi18-9 cast steel, which had the hardness of 258HV0.02. The abrasive wear resistance of the tested chromium-nickel cast steel, measured in the Miller test, increased by at least 20% (with the content of 1.3 wt% Ti). Increasing the Ti content in the samples to 5.3 and 6.9 wt% reduced the wear 2.5 times compared to the common GX2CrNi18-9 cast steel.

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Sposoby hartowania wyrobów stalowych z węglikowymi warstwami dyfuzyjnymi

Młynarczak A.

Inżynieria Materiałowa

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2008

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Vol. 29, nr 6

792-794

PL

W pracy przedstawiono możliwości hartowania wyrobów stalowych z wytworzonymi dyfuzyjnymi warstwami węglików chromu, wanadu i tytanu. Warstwy te wytwarzane metodą proszkową na stalach narzędziowych mają twardość od 2000 do 5000 HV 0,05, a twardość podłoża stalowego od 250 do 350 HV 0,05. Dlatego narzędzia i części maszyn z warstwami węglikowymi pracujące w warunkach obciążeń dynamicznych muszą być dodatkowo hartowane w celu utwardzenia podłoża stalowego pod warstwą. Przedstawiono wyniki tradycyjnego hartowania wyrobów bez atmosfery ochronnej, obróbki w specjalnie dopasowanej do wyrobu retorcie chłodzonej wodą oraz utwardzania warstwy wierzchniej z zastosowaniem lasera technologicznego.

EN

In the study the possibilities of hardening of steel products with diffusion carbide coatings of chromium, vanadium and titanium were presented. The coatings produced with pack cementation method on tool steels represent hardness within the range from 2000 to 5000 HV0.05 ,the hardness of the steel base being from 250 to 350 HV0.05. Therefore tools and parts of machines with carbide coatings working under dynamic load must be additionally quenched in order to harden the steel base under the coating. There were presented the results of traditional quenching of products without protective atmosphere, the treatment in the especially adjusted to the product water cooled retort and hardening of surface coating with technological laser.