CN1162228C - Composite ceramic roller for hot rolling - Google Patents

Abstract

The present invention relates to a composite ceramic roller for hot rolling, which is characterized in that tungsten carbide, cobalt, chromium nickel and zirconium oxide are mixed according to certain proportion, and moulding, cold press moulding, pre-sintering and vacuum pressure sintering are carried out to the mixture; then, a blank is machined by the known technology so that a desired product is obtained. The product of the present invention has the bending strength of 2200 to 2500Mpa, the hardness of 75 to 85 HRA and the density of 10 to 14 g/sq. cm. After trials, the product with a single groove has the maximum rolling quantity of 1100 tons and the average rolling quantity of 713.28 tons. Compared with the same class roller of China, the product with a single groove has the rolling tonnage increased by 400 tons.

Description

A kind of hot rolled ribbed steel bar composite ceramic roller

Technical field

The present invention relates to roll technology, more particularly, is the roll that a kind of high-speed rod-rolling mill finishing mill hot rolling is used.

Background technology

At present, the employed roll for hot-rolling of the high-speed rod-rolling mill of use is made through technologies such as hot pressed sinterings by wolfram varbide and two kinds of compositions of cobalt, and the shortcoming of this roll is to wear no resistance, heat-resistant cracking is poor, bending strength is low, and work-ing life is short, the high many shortcomings of roll change rate.

Summary of the invention

The objective of the invention is at shortcoming of the prior art, propose a kind of higher bending strength that has, wear-resisting preferably, heat-resistant cracking energy, and the roll for hot-rolling that can increase the service life.

Realize the main technical schemes of the object of the invention: the glue system material → dress mould → coldmoulding → presintering → vacuum pressed sintering → blank roughing → precision work → ground finish → open cell type of wolfram varbide, cobalt, chromium, nickel, zirconium white composition being prepared burden by a certain percentage → batch mixing → mix → open screw thread → detection promptly obtains required product.

Roll composition of the present invention and content thereof:

Wolfram varbide (WC) 50-80%, nickel (Ni): 9-20%, cobalt (Co) 9-20%, chromium (Cr): 0.5-1.0%, zirconium white (ZrO ₂): 0.5-10%, above-mentioned percentage number average is 100 in composition weight sum.

The preparation technology of roll for hot-rolling of the present invention may further comprise the steps:

(1) batch mixing: wolfram varbide, cobalt, chromium, nickel, zirconium white composition are prepared burden in desired ratio, and ball-milling technology routinely mixes then;

(2) mix glue system material: in gasoline-rubber mix solution, add the compound that step (1) makes, make granularity 〉=200 purpose mixed powders again, described gasoline compares=2 with the mixed weight of rubber, the volume ratio of the compound of described gasoline-rubber mix liquid and step (1) is 1: 1, and described gasoline is 93 ^#Gasoline, described rubber are paracril;

(3) coldmoulding: the mixed powder that step (2) the is obtained metal pattern of packing into, compression moulding at room temperature, pressing pressure≤7KN/cm ²

(4 presintering: to the rolled-up stock of step (3), at 500-700 ℃ of following pre-burning 24-48 hour;

(5) vacuum pressed sintering: to the pre-thermojunction spare of step (4) in 10 ^-2-10 ^-3Pressure sintering under the pa condition, its pressure are 0.7-2.1KN/cm ², obtain blank;

(6) machining process routinely carries out roughing → precision work → ground finish → open cell type → open screw thread → detection to step (5) blank, obtains meeting the composite ceramics roll for hot-rolling of relevant country, industry or company standard.

WC of the present invention can improve the hot-cracking resistance and the wear resistance of product; Described Co, Ni are caking agent, and its different proportioning can obtain the roll for hot-rolling of different hardness; Described ZrO ₂Can improve the intensity of product; Described Cr can improve the corrosion-resistant degree of product.

Major advantage of the present invention:

Composite ceramic roller of the present invention, because its prescription has significant difference with prior art, therefore the product bending strength that makes reaches 2200-2500Mpa, hardness 75-85HRA, density: 10-14g/cm ³, on probation through the Tang Gang high-speed wire factory, guaranteeing under the good condition of finished product wire rod surface quality, 713.28 tons of single groove amount of rolling average out to, the highest amount of rolling of single groove is 1100 tons, compares with similar roll, the rolling tonnage of single groove improves 400 tons.

Embodiment

Further specify characteristics of the present invention below by concrete example:

Example 1

With 50 kilograms of WC, 20 kilograms of Co, 20 kilograms of Ni, 9 kilograms of ZrO ₂, 1 kilogram of Cr ball-milling technology routinely be incorporated into gasoline-rubber mix solution after mixing, making granularity is 200 purpose mixed powders, in its metal pattern of packing into, compression moulding under the room temperature, pressure is 7KN/cm ², again through 600 ℃ of pre-burnings 30 hours, then 10 ^-3Pa and 1.5KN/cm ³Vacuum pressed sintering under the condition, the blank that obtains is by roughing → precision work → ground finish → open cell type → open screw thread → detection promptly to obtain the hot rolled ribbed steel bar composite ceramic roller.After testing, the bending strength 2000Mpa of this product, hardness 〉=80HRA, density 13.9g/cm ³

Example 2-4

Composition and the salient features of example 2-4 see Table 1, and preparation process is with example 1.

Table 1

Project	Example 2	Example 3	Example 4
				WC，％	60	70	80
Co，％	15	10	15
				Ni，％	20	16	4
ZrO 2，％	4.5	3	0.5
				Cr，％	0.5	1	0.5
Bending strength, MPa	2200	2400	2500
				Hardness, HRA	75-80	80-83	83-85
Density, g/cm 3	13.0	13.5	14.0

Claims (1)

1. hot rolled ribbed steel bar composite ceramic roller is characterized in that roll composition and content thereof (is 100 in composition weight sum):

Wolfram varbide 50-80%, nickel 9-20%, cobalt 9-20%, chromium 0.5-1.0%, zirconium white 0.5-10%.

The preparation method of described hot rolled ribbed steel bar composite ceramic roller may further comprise the steps:

(1) batch mixing: wolfram varbide, cobalt, chromium, nickel, zirconium white composition are prepared burden in desired ratio, and ball-milling technology routinely mixes then;

(2) mix glue system material: in gasoline-rubber mix solution, add the compound that step (1) makes, make granularity 〉=200 purpose mixed powders again, described gasoline compares=2 with the mixed weight of rubber, and the volume ratio of the compound of described gasoline-rubber mix liquid and step (1) is 1: 1;

(3) coldmoulding: the mixed powder that step (2) the is obtained metal pattern of packing into, compression moulding at room temperature, pressing pressure≤7KN/cm ²

(4 presintering: to the rolled-up stock of step (3), at 500-700 ℃ of following pre-burning 24-48 hour;

(5) vacuum pressed sintering: to the pre-thermojunction spare of step (4) in 10 ^-2-10 ^-3Pressure sintering under the pa condition, its power are 0.7-2.1KN/cm ², obtain blank;

(6) machining process routinely carries out roughing → precision work → ground finish → open cell type → open screw thread → detection to step (5) blank, obtains meeting the composite ceramics roll for hot-rolling of relevant country, industry or company standard.