C-Si-N silicon steel hearth roller sleeve and manufacture method thereof

Abstract

The invention relates to a C-Si-N silicon steel hearth roller sleeve and a manufacture method thereof. The manufacture method comprises the following steps of: mixing 15-35 weight percent of carbon raw material granule, 20-40 weight percent of crude carbon raw material powder being smaller than or equal to 180 meshes, 40-55 weight percent of fine carbon raw material powder being smaller than or equal to 300 meshes and 1-15 weight percent of fine Si powder, additionally adding a bonding agent accounting for 5-18 weight percent of the mixture and mixing as well as grinding for 15-30 minutes; pressing and molding into a silicon steel hearth roller sleeve blank after mixing and grinding, loading the sleeve blank into a sintering furnace with an N2 atmosphere, preserving heat for 4-8 hours at 1,450-1,700 DEG C and sintering; maintaining the nitridized and sintered sleeve blank for 15-30 minutes under the condition of 10,000-20,000Pa, injecting tar and continuing to maintain for 15-30 minutes under the condition of 10,000-20,000Pa; preserving heat for 4-8 hours at 1,400-1,450 DEG C in a reducing atmosphere; and processing through a lathe and a grinder until the surface roughness is not larger than 12.5. The sleeve has the characteristics of good abrasive resistance, good oxidation resistance, high strength, low porosity, no nodules and long service life.

Description

technical field [0001] The invention belongs to the technical field of hearth roller sleeves. In particular, it relates to a C-Si-N silicon steel hearth roll sleeve and a preparation method thereof. Background technique [0002] Since the 1980s, the iron and steel industry has developed continuous annealing furnaces for the production of high-quality steel sheets, resulting in the actual demand for high-quality hearth rolls, and this demand has grown with the development of the iron and steel industry. Due to the special physical properties of silicon steel sheets, the continuous annealing furnace for producing silicon steel sheets has more unique requirements for hearth roll sleeves. At present, the sleeves used for silicon steel hearth rolls are carbonaceous material sleeves. [0003] Patents JP57140377A, JP57137419A, CN1117479, CN1994967, CN2199206 and CN 1092324A respectively describe silicon steel hearth roller sleeves and their preparation and surface treatment method...

AI Technical Summary

Problems solved by technology

However, there are also some outstanding problems in production and application, such as nodules on the surface of the roller and scratches on the silicon steel plate, which affect the electrical properties of the silicon steel plate and cause waste; poor wear resistance, and the middle of the sleeve is worn and thinned after a period of use. Form a "dumbbell shape", causing the steel plate to deform and produce defective products; the oxidation resistance is not good, and it is gradually destroyed by the high temperature H in the furnace under the high temperature conditions of heat treatment silicon steel 2 Oxidation by O gas makes the surface of the carbonaceous hearth roller sleeve loose and pockmarked, reduces wear resistance, and shortens the service life. At the same time, a series of problems such as aggravating nodules and affecting the quality of silicon steel plates will also occur.