SU1315513A2 - Steel - Google Patents

Abstract

The invention relates to the field of metallurgy, namely to the composition of steel intended for the manufacture of cold rolling rolls. The purpose of the invention is to improve the contact-fatigue characteristics and grindability of steel. This is achieved by introducing niobium and copper into steel in the following ratio of components, wt.%; Carbon 0.72-0.82; manganese 0.20-0.40; silicon 0.80-1.20; chromium 1.10-1.40; molybdenum 0.20-0.30; cerium 0.05-0.10; niobium 0.02-0.15; copper 0.35-0.55; iron else. The use of steel will allow a 1.5-fold increase in operational resistance rolls, reduce downtime mills. 2 tab. with (O sove ate with N)

Description

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The invention relates to metallurgy, in particular, to a composition of alloyed steel intended for the manufacture of cold rolling rolls, and is an improvement of the invention according to the authors. St. No. 601322.

The aim of the invention is to improve the contact-fatigue characteristics and grindability of steel.

The chemical composition of the investigated proposed and known steels and their corresponding properties are given in table. 1 and 2.

The metal is poured at 1510 ° C into a cast-iron back-octagonal octahedral mold, heated to 140 ° C, with a 50 kg hand bucket. Cast ingots weighing 40 kg are cooled in molds to 100 ° C.

The forging of ingots is carried out on the hammer with a force of 0.01 MN in the temperature range of 1140–900 ° C with a contraction of 3 for 1 l of all ingots. The forgings are cooled with a furnace and then subjected to isotherms

chesky annealing by the mode: heating to 840 ° С, holding 3 h, cooling with hover to C, cooling to 15 h, cooling with a furnace to. After isothermal annealing, forgings are cut into blanks for testing.

The propagation of initiated cracks, hardenability, prokalizvaemost, grindability, durability under cyclic contact loading is carried out after the final thermal treatment - induction electrical hardening with low-temperature tempering according to the mode: heating ТПЧ to 920 ° С, cooling

Experienced

10.70 0.19 0.74 1.0 0.15 0.03 0.01 0.29 Else

Proposed

20.72 0.20 0.80 1.10 0.20 0.05 0.02 0.35 - 0, 78 0.36 0.93 1.32 0.24 0.08 0.10 0.46 -

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sprayer (water), leave at 2 hours.

Tests by definition of durability at cyclic contact, loading in the field of limited endurance at maximum contact voltage 6 ,. 2744 MPa (280 kgf / mm) of the proposed and known steel are produced in the state of final heat treatment (induction electrocapacity and low-temperature tempering).

The tests are carried out on a three-roller machine on samples 0 35x5mm. The sample test medium is Industrial-20 oil, the number of sample revolutions is 4725 rpm.

The use of steel makes it possible to increase the operational durability of the rolls by 1.5 times, to reduce downtime of mills.

Claims (1)

Invention Formula Steel on auth. No. 601322, characterized in that, in order to improve contact-fatigue characteristics and grindability, it additionally contains niobium and copper with the following ratio of components, wt.%: five 0 Carbon Manganese Silicon Chromium Molybdenum Cerium Niobium Copper Iron 0.72-0.82 0.20-0.40 0.80-1.20 1.10-1.40 0.20-0.30 0.05-0.10 0.02-0.15 0 , 35-0,55 Else Table 1 A0,820.40 1.20 1.40 0.30 0.10 0.15 0.55 - Experienced 50.890.45 1.24 1.45 0.39 0.12 0.19 0.60 - Lime 0,720,40 0,90 1,14 0,26 0,05 --- Note. Compositions 1 and 5 have a content of components with extreme values. Tabl «2 VNIIPI Order 2320/28 Production polygr, pr-tie, Uzhgorod, st. Project, 4 Continuation of table 1 Circulation 604 Subscription