Multielement high-chromium wear-resisting cast-iron sieve-plate and production thereof

Abstract

An antiwear multi-element screening plate made of high-Cr cast iron contains C (2.2-3.2 wt.%), Cr (18-28), Mn (0.6-1.5), Si (0.4-1.0), Mo (0.4-1.5), Ni (0.5-1.2), Nb (0.1-0.5), Ca (0.01-0.08), Zn (0.008-0.050), Mg (0.002-0.010), Ce (0.003-0.10), Ti (0.08-0.15) and Fe (rest). It is made up by electric furnace and cold hardened resin-sand mould. Its advantages are high bending strength, hardness, antiwear performance and impact toughness, and low cost.

Description

1. Technical field [0001] The invention belongs to the technical field of sintered ore screening, and relates to sieve plates for vibrating screens of various sintering machines and a manufacturing method thereof, in particular to a multi-component high-chromium wear-resistant cast iron sieve plate and a manufacturing method thereof. 2. Background technology [0002] The vibrating screen of the sintering machine is an important equipment for screening sinter, which is used to classify the sinter and screen out the powder smaller than 5mm in the sinter to meet the particle size requirements of blast furnace production. The sieve plate is a key component of the vibrating screen, and the quality of the sieve plate directly affects the productivity of the entire sintering operation system and the screening effect of sintering ore. Since the temperature of hot sinter is as high as 780-850 °C, the sieve plate often suffers from oxidation, high-temperature creep fracture, thermal s...

AI Technical Summary

Problems solved by technology

CrMnN steel is a high-alloy heat-resistant steel (alloy content up to 33%). Its as-cast structure is austenite, which has high strength and toughness. At room temperature, its σ b ≥490MPa, δ≥8%, but the hardness is low (about HRC25), resulting in severe wear of the sieve plate

In order to improve the service life of the sieve plate, materials such as Cr12 and Cr5Mn have been developed in China, but the service life is short due to the low hardness

In the Chinese patent document CN1176159, a kind of sieve plate cast by gasification mold (lost foam) is disclosed. The main components of the sieve plate are 2%-3%C, 20%-30%Cr, 18%-22%Ni, Mn <1.5%, Si<2.0%, although this sieve plate has high wear resistance, the Ni content is too high and the production cost is too high

Due to the low bonding strength between the surfacing layer and the steel plate matrix, this kind of sieve plate is easy to crack and peel off during use, which affects the wear resistance of the sieve plate. At the same time, the inner hole of the sieve plate is still made of ordinary steel with low hardness and poor wear resistance. The holes are severely worn, and this kind of sieve plate still has shortcomings such as complicated manufacturing process, so it is less popularized and applied.

In addition, high-manganese steel sieve plates have been developed in China. Because the sintered ore and the sieve plate mainly perform relative frictional motion, the impact force on the sieve plate is small, and the surface of the sieve plate cannot produce a large amount of deformed martensite to make the surface cold. Hardened and therefore less wear-resistant

High-chromium-nickel steel is mainly used as sieve plate material in foreign countries, such as No4825 in Germany, SGS17 in Japan, X20H14G2 in the former Soviet Union, 309S24 in the United Kingdom, and S30900 in the United States. High-chromium-nickel steel has good high temperature performance, but low hardness and poor wear resistance. , the service life of the sieve plate is short