CN101177768A - Method for preparing niobium sheet metal strip - Google Patents

Abstract

The invention discloses a metallic niobium strip preparation method, which relates to a method of adopting a forged rolling technology to prepare a metallic niobium strip with high elongation and high grain size grade. The preparation process comprises the following procedures in sequence: (1) an electron beam melting niobium ingot with 150mm to 160mm diameter is forged by a pneumatic hammer at a temperature of 800 DEG C to 1100 DEG C; the working modulus in the forging process is adjusted to one time of 30 percent to 40 percent of upsetting and one time of 40 percent to 50 percent of drawing out, and the upset forging working modulus is 50 percent to 70 percent; (2) the working modulus of the first pass of rolling is more than or equal to 40 percent, the working modulus of the second pass is more than or equal to 35 percent, and after the two passes the working modulus of each pass is more than or equal to 15 percent; the extended direction of an blank in the rolling process is always the axial direction of a starting ingot; (3) an annealing process of preserving heat for 3 hours to 4 hours at a temperature of 850 DEG C to 900 DEG C is employed. A refractory metallic niobium long strip which is endowed with excellent deep drawing performance can be obtained by using the method of the invention, with an elongation of 30 percent to 41 percent and a grain size grade of 8.5 to 10, and an electrode tip which is applied to CCFL can be obtained, with a diameter of 1.6mm and a height of 8mm.

Description

A kind of method for preparing niobium sheet metal strip

Technical field

A kind of method for preparing niobium sheet metal strip relates to a kind of method that rolling technology prepares the niobium sheet metal strip with high-elongation and high grain size number performance of forging that adopts.

Background technology

The niobium band is one of main raw of making at present on cold-cathode fluorescence lamp (CCFL) pipe electrode head, compares with the molybdenum band to have deep-draw than higher, and length is more suitable for the characteristics in automatic production.CCFL has just solved short problem of low lightness and work-ing life at present as liquid crystal screen backlight, and popularity has reached 31% in backlight manufacturer, in evaluation and test the five-year, uses the CCFL of niobium electrode head will account for 50% of the total market size.Whole world niobium band demand reached 7000 tons in 2007, belonged to long-living life cycle product in electron trade, and influence factor is based on material price.At present, because the niobium raw material specification is little, the niobium band of production exists length short, extension property instability, the problem that grain size number is on the low side.

Summary of the invention

Purpose of the present invention be exactly at above-mentioned deficiency, a kind of method for preparing niobium sheet metal strip that can effectively improve finished product band length, extension property stability and improve grain size number simultaneously is provided.

The objective of the invention is to be achieved through the following technical solutions.

A kind of method for preparing niobium sheet metal strip,, its preparation process comprises following process successively:

(1) with the electron beam melting niobium ingot of diameter 150～160mm, under 800～1100 ℃ of temperature, forges with air hammer; Working modulus is controlled to be jumping-up 30%～40% once during forging, pulls out 40%～50% once, and clapping flat working modulus is 50%～70%;

(2) rolling first pass reduction is that 〉=40%, second pass reduction is 〉=35%, afterwards every time working modulus 〉=15%; The direction of the prolongation of operation of rolling blank is the axial of starting ingot all the time;

(3) adopt 850～900 ℃ of annealing processs that are incubated 3～4h.

The method for preparing niobium sheet metal strip of the present invention,, it is characterized in that adopting argon arc protection welding process, before finished product is rolling, blank connected postwelding and be rolled again.

Method of the present invention adopts the long band of refractory metal niobium of the present invention's preparation to have high-elongation and high grain size number performance, and thickness range is 0.1～0.254mm.Adopt the high temperature forging method, the quick mode of texturing by flat-die forging can be replied by dynamic recrystallization blank in forging process, and the original coarse-grain of last blank obtains refinement; Because the operation of rolling initial stage adopts big working modulus complete processing, the crystal grain in the finished product band tissue has obtained fully refinement comprehensively, controls by thermal treatment process and obtains unit elongation height, band that grain size number is high.Can obtain unit elongation 30～41%, the long band of the refractory metal niobium of the excellent deep drawability of the acquisition that grain size number is 8.5～10 grades can be washed into diameter 1.6mm, the CCFL top electrode of height 8mm.

Description of drawings

Fig. 1 organizes metallograph for 850 ℃ of 3h annealing bands that adopt the inventive method preparation.

Fig. 2 organizes metallographic for 900 ℃ of 3h annealing bands that adopt the inventive method preparation

Embodiment

A kind of method for preparing niobium sheet metal strip,, its preparation process comprises following process successively:

(1) forging temperature of the electron beam melting niobium ingot of diameter 150～160mm is between 800～1100 ℃; The forging mode is the air hammer open die forging; Working modulus is controlled to be jumping-up 30%～40% once during forging, pulls out 40%～50% once, and clapping flat working modulus is 50%～70%; Blank no longer melts down heating in the forging process.

First passage adopts 〉=40% working modulus when (2) rolling, and second passage adopts 〉=35% working modulus, every time working modulus 〉=15% afterwards; The direction of the prolongation of operation of rolling blank is the axial of starting ingot all the time.

(3) adopt argon arc protection welding process, before finished product is rolling blank connected postwelding and carry out tension rolling again, make 0.150mm thickness band length can reach more than 200 meters, 0.254 thickness band length can reach more than 120 meters.

(4) under the effect of feature (1) and feature (2), adopt the annealing process of 850～900 ℃ of insulation 3～4h, the long band of refractory metal niobium of 8.5～10 grades of unit elongation 30%～38%, grain size number can be obtained, diameter 1.6mm can be washed into, the CCFL top electrode of height 8mm.

Embodiment 1

One on electron beam secondary smelting ingot, in 800 ℃ electric furnace, heat 80min, upset ratio 35% to length 130mm pulls out 50% to length 195mm again, claps flat one-tenth 45 * 150 * 550mm, rolling first passage 40% to thickness 27mm, second passage 35 is rolled down to 2.0mm thickness again to thickness 17.5mm and carries out tension rolling to 0.2mm thickness, and 900 ℃ of 3h annealing of finished product back band unit elongation reaches 38%, 10 grades of grain fineness numbers, mechanical property is shown in Table 1,110 meters of band length.

The room-temperature mechanical property of table 1 embodiment 1 niobium band

Tensile strength, Rm	Yield strength, Rp0.2	Unit elongation, %	Hardness, HV	Grain fineness number
					285MPa	177MPa	38	82	10 grades

Embodiment 2

Three on secondary smelting ingot, in 800 ℃ electric furnace, heat 80min, upset ratio 35% to length 130mm, pull out 50% to length 195mm again, clap flat one-tenth 45 * 150 * 550mm, rolling first passage 40% to thickness 27mm, second passage 35 to thickness 17.5mm, be rolled down to 2.0mm thickness again, three blank butt welding connected into one, carry out tension rolling again to 0.2mm thickness with the argon arc welding mode, 900 ℃ of 3h annealing of finished product back band unit elongation reaches 34%, 10 grades of grain fineness numbers, mechanical property is shown in Table 2,298 meters of band length.

The room-temperature mechanical property of table 2 embodiment 2 niobium bands

Tensile strength, Rm	Yield strength, Rp0.2	Unit elongation, %	Hardness, HV	Grain fineness number
					270MPa	170MPa	34	79.3	10 grades

Embodiment 3

Three on secondary smelting ingot, in 1000 ℃ of electric furnaces, heat 75min, upset ratio 35% to 100mm, pull out 50% to 160mm again, clap flat one-tenth 45 * 160 * 350mm, rolling first passage 40% to thickness 27mm, second passage 35% to thickness 17.5mm, be rolled down to 2.0mm thickness again, three blank butt welding connected into one, carry out tension rolling again to 0.1mm thickness with the argon arc welding mode, 850 ℃ of 3h annealing of finished product back band unit elongation reaches 31%, 9 grades of grain fineness numbers, mechanical property is shown in Table 2,400 meters of band length.

The room-temperature mechanical property of table 3 embodiment 3 niobium bands

Tensile strength, Rm	Yield strength, Rp0.2	Unit elongation, %	Hardness, HV	Grain fineness number
					235MPa	145MPa	31	83	9 grades

Claims (2)

1. method for preparing niobium sheet metal strip, its preparation process comprises following process successively:

(1) with the electron beam melting niobium ingot of diameter 150～160mm, under 800～1100 ℃ of temperature, forges with air hammer; Working modulus is controlled to be jumping-up 30%～40% once during forging, pulls out 40%～50% once, and clapping flat working modulus is 50%～70%;

(2) rolling first pass reduction is that 〉=40%, second pass reduction is 〉=35%, afterwards every time working modulus 〉=15%; The direction of the prolongation of operation of rolling blank is the axial of starting ingot all the time;

(3) adopt 850～900 ℃ of annealing processs that are incubated 3～4h.

2. the method for a kind of niobium sheet metal strip according to claim 1 is characterized in that adopting argon arc protection welding process, blank connected postwelding to be rolled before finished product is rolling again.