CN103459631B

CN103459631B - Mo

Info

Publication number: CN103459631B
Application number: CN201280014329.2A
Authority: CN
Inventors: 角仓孝典; 泷田朋广
Original assignee: ALMT Corp
Current assignee: ALMT Corp
Priority date: 2011-03-25
Filing date: 2012-01-11
Publication date: 2016-06-08
Anticipated expiration: 2032-01-11
Also published as: CN103459631A; JP5160660B2; JP2012201930A; KR20140002010A; EP2690185A4; US20140014235A1; WO2012132489A1; KR101587837B1; EP2690185A1

Abstract

The problem of the present invention is in that to provide a kind of Mo, it has industrialness advantage as described below: this Mo can cause secondary recrystallization at lower than conventional temperature, and enables to the tissue after secondary recrystallization and be made up of the huge crystal grain that crystal boundary is few and resistance to creep properties is excellent. The Mo of the present invention is equivalent in the region of the degree of depth of 1/the 5 of gross thickness along thickness of slab direction far from surface, having part as described below at least partially: when carrying out X-ray diffraction mensuration, this part has crystal diffraction face (110) and (220) respective peak intensity region less than the peak intensity of (211).

Description

Mo

Technical field

The present invention relates to a kind of Mo.

Background technology

Mo is used to the position that high-temperature structural material and component materials etc. require at high temperature to have thermostability sometimes. But, for not intentionally adding the pure Mo of element-specific in the material, if used above at about 1000 DEG C, then recrystallize, be changed to equi-axed crystal tissue. Easily causing Grain Boundary Sliding when producing equi-axed crystal tissue, thus causing that resistance to creep properties declines, its result is easily to deform.

Therefore, when applied at elevated temperature Mo more than 1000 DEG C, it is necessary to improve the resistance to creep properties under high temperature.

As the method improving Mo resistance to creep properties under the high temperature conditions, it is known to use more than temperature even if recrystallization temperature is increased to or forms any means that recrystallization and the resistance to creep properties still tissue of excellence occur.

Wherein, as described in non-patent literature 1, as the method improving recrystallization temperature, it is known to by use TZM alloy (containing titanium, zirconium, carbon molybdenum alloy) improve the method (non-patent literature 1) of primary recrystallization temperature. But, the recrystallization temperature of TZM alloy is about 1400 DEG C, though this recrystallization temperature is higher compared with pure Mo, but can form equi-axed crystal tissue after recrystallization, the same with pure Mo when therefore more than recrystallization temperature easily deforms.

Additionally, even if as forming the method that recrystallization and the resistance to creep properties still material of excellence occur, known have following method: by combining Al, Si, K as described in non-patent literature 2, is consequently formed the luminal tissue along the crystal grain of growing up of machine direction elongation of the tissue after making recrystallization; Or by the addition of La as described in non-patent literature 3₂O₃Deng the plastic working of the molybdenum sintered body high working modulus of enforcement of rare-earth oxide, it is consequently formed the luminal tissue (non-patent literature 2,3) along the crystal grain of growing up of machine direction elongation of the tissue after making recrystallization. But, when Mo being forged or rolling such plastic working, additive or organizational controls for improving characteristic become the reason resulting in be full of cracks, have influence on the decline of the yield rate of certified products, also can produce due to the anisotropy of the flexural property etc. organizing anisotropy to cause in addition, it is therefore desirable to restriction Mo size. Further, when be used for as fire that, Mo such with backing plate constitute with by other elements when firing the purposes that thing etc. contacts, sometimes the thing etc. of firing contacted with Mo reacts with the additive in Mo, it is possible to the kind of thing is fired in restriction.

On the other hand, as the method that the pure Mo that plastic working is good improves resistance to creep properties, the method having the crystal grain gigantism that make use of secondary recrystallization to cause.This be due to: if making crystal grain gigantism, then crystal crystal boundary reduce, thus being difficult to cause the sliding of crystal boundary, as significant example, it is possible to enumerate monocrystal material.

Secondary recrystallization is illustrated herein, such as, when being Mo, by carrying out the heat treatment of 1000 DEG C��1100 DEG C, the fibrous tissue formed by plastic workings such as rollings is with the strain that produced by plastic working for core, again the crystal grain of 20 ��m��about 30 ��m it is changed to, this phenomenon is called primary recrystallization or is only called recrystallization, at high temperature, the material being made up of this primary recrystallization crystal grain is carried out heat treatment further, thus adjacent primary recrystallization crystal grain combines repeatedly, grow up, it is changed to huge crystal grain, this phenomenon is called secondary recrystallization (non-patent literature 4).

More specifically, slow gigantism is to some tens of pm��hundreds of microns along with heat supply for the crystal grain about some tens of pm after primary recrystallization, but such as when reaching certain temperature, or when certain temperature has carried out long-time heating, can sharply grow up, form the crystal grain of more than millimeter unit. Such crystal grain sharply gigantism phenomenon is called secondary recrystallization.

Therefore, in patent documentation 1, the crystal grain control molybdenum board material that purity is more than 99.9% being substantially not added with additive carried out in the hydrogen stream of 2250 DEG C 0.5 hour��5 hours processes and forms the huge discoideus crystal grain that diameter is 15mm��150mm, it is possible to form the sheet material (patent documentation 1) 1800 DEG C of resistance to creep propertieses excellences.

Prior art literature

Patent documentation

Patent documentation 1: Japanese Laid-Open Patent Publication 61-143548 publication

Non-patent literature

Non-patent literature 1:T.Mrotzeket.al.; " Hardeningmechanismsandrecrystallizationbehaviourofsevera lmolybdenumalloys " InternationalJournalofRefractoryMetals&HardMaterials; 2006; (24), p298-305.

Non-patent literature 2:Y.Fukasawaet.al., " VeryHighTemperatureCreepBehaviorOfP/MMolybdenumAlloys ", Proceedingsofthe11thInternationalPlanseeSeminar, vol.11985, p295-308.

Non-patent literature 3:R.Biancoet.al., " MechanicalPropertiesofOxideDispersionStrengthened (ODS) Molybdenum ", MolybdenumandMolybdenumAlloysEditedbyA.Crowson, E.S.Chen, J.A.Shields, andP.R.Subramanian, 1998, p125-142.

Non-patent literature 4:(society) powder body Powder Metallurgy Organized compiles " powder body powder metallurgy term dictionary ", Nikkan Kogyo Shimbun's ((society) powder body powder metallurgy meeting " powder body powder used in metallurgy dictionary ", daily magazine Gong Xin society), 2001, p558��559.

Summary of the invention

The problem that invention to solve

Technology described in patent documentation 1 does not use additive, it can be said that be a kind of good technology, it does not have be full of cracks during above-mentioned plastic working produces, without the problem of certified products decrease in yield; And do not have and be burned the problem that thing reacts; And also without the plastic working of high working modulus, thus the anisotropic of amorphous anisotropy and characteristic.

But, for the molybdenum board material described in patent documentation 1, the heat treatment temperature needed to produce secondary recrystallization is 2250 DEG C, if being that 1000 DEG C consider from primary recrystallization starting temperature, then said temperature is very high, from productivity and these aspects of cost of energy, it is desirable to reduce the heat treatment temperature produced required for secondary recrystallization further.

The present invention completes in view of the above problems, its object is to provide a kind of Mo, this Mo has industrialness advantage, compared with the past, secondary recrystallization can be caused with low temperature, and enable to the tissue after secondary recrystallization and be made up of the huge crystal grain that crystal boundary is few and resistance to creep properties is excellent.

In order to solve the problems referred to above, the present inventor is conceived to the intensity in each crystal diffraction face based on X-ray diffraction of Mo and the relation of secondary recrystallization behavior, and conduct in-depth research, found that: for the thickness direction of Mo, between peak intensity and the secondary recrystallization temperature in the specific crystal diffraction face of certain area, there is important relationship.

It has further been discovered that, by controlling described peak intensity, compared with conventional art, it is possible to cause the gigantism of the crystal grain based on secondary recrystallization with low temperature, thus completing the present invention.

Namely, 1st mode of the present invention is a kind of Mo, it is characterized in that, corresponding to there is part as described below at least partially in the region of the thickness direction degree of depth from surface is gross thickness 1/5th: when carrying out X-ray diffraction mensuration, this part has crystal diffraction face (110) and (220) respective peak intensity region less than the peak intensity of (211).

2nd mode of the present invention is a kind of Mo, it is characterised in that the Mo described in the 1st mode is thermally treated resulting in by the temperature that this Mo is more than 1700 DEG C, and the mean diameter based on segment method of the crystal grain in cross section is more than 15mm.

3rd mode of the present invention is a kind of heating furnace structure member, it is characterised in that this heating furnace structure member has the Mo described in the 1st or the 2nd mode.

4th mode of the present invention is that one is fired with backing plate, it is characterised in that this is fired has the Mo described in the 1st or the 2nd mode with backing plate.

The effect of invention

Can providing a kind of Mo in the present invention, it has industrialness advantage, compared with the past, it is possible to cause secondary recrystallization with low temperature, and enables to the tissue after secondary recrystallization and be made up of the huge crystal grain that crystal boundary is few and resistance to creep properties excellence.

Accompanying drawing explanation

Fig. 1 is the axonometric chart of the face of the molybdenum board material illustrating the present invention and rolling direction.

Fig. 2 is the partial perspective view of the molybdenum board material of the present invention.

Fig. 3 is an illustration for the figure of line segment ratio juris.

Fig. 4 A is the ideograph of the tissue profile of the molybdenum board material illustrating the present invention and size, indicates that the figure of the tissue profile after rolling and size.

Fig. 4 B is the ideograph of the tissue profile of the molybdenum board material illustrating the present invention and size, indicates that the figure of the tissue profile after primary recrystallization and size.

Fig. 4 C is the ideograph of the tissue profile of the molybdenum board material illustrating the present invention and size, indicates that the figure of the tissue profile after secondary recrystallization and size.

Fig. 5 is the figure of the X-ray diffraction result of the molybdenum board material illustrating that embodiments of the invention relate to.

Fig. 6 is the figure of the X-ray diffraction result of the molybdenum board material illustrating that comparative example relates to.

Fig. 7 indicates that the table of the heating-up temperature of the molybdenum board material involved by embodiment and comparative example and the relation of crystal particle diameter.

Fig. 8 is the schematic diagram of the stress test of the resistance to creep properties evaluation of the molybdenum board material involved by embodiment and comparative example.

Fig. 9 indicates that the table of the result of the stress test of the molybdenum board material that embodiment and comparative example relate to.

Detailed description of the invention

Hereinafter, with reference to accompanying drawing, the preferred embodiment of the present invention is described in detail.

As it has been described above, the Mo of the present invention is the material that the peak intensity in the specific crystal diffraction face of certain area on thickness direction has been controlled, below, for the condition of the Mo of the present invention, it is described in detail with sheet material for example.

For the composition of the molybdenum board material of the present invention, it is mainly composed of molybdenum.

Specifically, as consider to such as carry out on the molybdenum board material of the present invention heat treated fire thing such at high temperature use the present invention sheet material time the pollution of material that is in contact with it, it is preferable that be made up of the molybdenum of more than 99.9 mass %, but be not limited to this. The such as material with molybdenum for main component (more than 98 mass %), more specifically, for instance, molybdenum contains the lanthanum-oxides (La of 0.1 mass %��2.0 mass %₂O₃) sheet material; Or in molybdenum containing the titanium of 0.3 mass %��1.0 mass %, the zirconium of 0.01 mass %��0.10 mass %, 0.01 mass %��0.1 mass % the sheet material of carbon can also similarly obtain causing the effects such as secondary recrystallization lower than conventional temperature. That is, molybdenum board material forms alloy with additive and can also obtain same effect.

The molybdenum board material of the present invention is that molybdenum powder carries out extrusion forming/sintering the material it implemented the plastic workings such as rolling or forging and obtains. Hereinafter, to obtaining the method for molybdenum board material and illustrate by rolling processing, but as long as being that the peak intensity based on X-ray diffraction of the present invention can be controlled, then manufacture method is not limited to this.

The preferred purity of molybdenum powder used to obtain the molybdenum board material of the present invention is more than 99.9 mass %. Additionally for powder characteristics such as the particle diameter of material powder and bulk densities with for obtaining the suppression process of sintered body and the method for sintering circuit and condition, as long as can obtain carrying out the density of plastic working degree and relative density is the sintered body of more than 90%.

It should be noted that when the relative density of sintered body is less than 90%, owing to the space in sintered body results in be full of cracks etc. when sheet material is carried out plastic working, be therefore not preferred.

Extrusion forming method as molybdenum powder, such as, use by Fsss method (Fischer's method, FicsherSub-SieveSizer) granularity measured is the molybdenum powder of 1.0 ��m��10 ��m, use well-known single axle pressuring machine or isostatic cool pressing pressuring machine (CIP) etc. to carry out extrusion forming, be consequently formed molded body. It addition, as the sintering method of molded body, it is possible to the heat treated that above-mentioned molded body carries out 1700 DEG C��2000 DEG C in the non-oxidizing atmospheres such as hydrogen, argon, vacuum is sintered.

Additionally, when having additive except the molybdenum of main component, in order to make additive be dispersed in sintered body, additionally also for plastic working after sintering not making yield rate be deteriorated, it is possible to powder characteristics such as the suitable purity setting additive and granularities.

Rolling for sintered body is processed, by controlling roller interval and the Reduction by rolling (=((thickness before rolling)-(thickness after rolling)) �� 100/ (thickness before rolling) unit %) of every 1 passage, thus control the intensity of particular crystal plane in the X-ray diffraction in following region, described region refer at least 1 face in the opposite face up and down of sheet material be equivalent to along thickness of slab direction from arbitrary surface thickness of slab 1/5th the region of the degree of depth. Product of the present invention can be controlled as described below: makes the Reduction by rolling of every 1 passage of rolling less than 20% (not including 0), so that when carrying out X-ray diffraction mensuration, sheet material opposite face up and down at least 1 face be equivalent to along thickness of slab direction from arbitrary surface thickness of slab 1/5th the degree of depth region in, crystal diffraction face (110) and (220) respective peak intensity are less than the peak intensity of (211).

Make the working modulus of every 1 passage of rolling less than 20% herein, it is owing to this is to ensure that the condition of intensity in the specific crystal diffraction face that can control the present invention, if Reduction by rolling is more than 20%, it is difficult to control to the intensity in crystal diffraction face, additionally also can break etc. due to rolling and cause reducing certified products yield rate. It addition, the lower limit of the Reduction by rolling of every 1 passage is more than 5%, more preferably more than 15%. This be due to: when less than 5%, rolling pass number can be increased and cause that manufacturing cost increases.

It addition, the thickness for being used for obtaining the sintered body of the molybdenum board material of the present invention is not particularly limited. It is thus possible, for instance in order to obtain the sheet material that thickness is 20mm, the thickness of sintered body is 50mm or 150mm.

Herein, if rolling general working rate (=(thickness of sintered body)-(final thickness of the sheet material after rolling) �� 100/ (thickness of sintered body) unit %) is not be at least more than 50%, then it is difficult to obtain the X-ray diffraction peak intensity of the present invention. It is more preferably more than 85%.

In order to meet working modulus and the general working rate of above-mentioned every 1 time, it is necessary to carry out tens processing (rolling pass number), for instance 20 times. Compared to implementing repeatedly processing (rolling pass number), the boundary of the rolling rate of every 1 time is set as 20% and the surface of molybdenum board material and the internal X-ray diffraction line graph that obtain have a great difference with it.

The ideograph of the texture of obtained molybdenum board material is shown in Fig. 4 A. Bacillar structure is formed by rolling.

<X-ray diffraction intensity>

Then, the X-ray diffraction intensity of the crystal face of the sheet material of the present invention is described. The schematic diagram of sheet material shown in Fig. 1. The ND face of sheet material is carry out the face rolled, the face namely contacted with Rolling roller, corresponding to the top and bottom of the defined sheet material of present embodiment.

Molybdenum board material for the present invention, when carrying out X-ray diffraction mensuration, sheet material opposite face up and down at least 1 face be equivalent to along thickness of slab direction far from surface thickness of slab 1/5th the region of the degree of depth, there is part as described below at least partially: this part has crystal diffraction face (110) and (220) respective peak intensity region less than the peak intensity of (211).

Namely, as in figure 2 it is shown, secondary recrystallization is brought by the present invention opposite face up and down that the significant points (namely controlling the region of the X-ray diffraction intensity of molybdenum board material) of the sheet material of appreciable impact is sheet material at least 1 face be equivalent to along thickness of slab direction from arbitrary surface thickness of slab 1/5th region.

It should be noted that herein " be equivalent to thickness of slab 1/5th region " be the material surface of sheet material after span eliminates the oxide being inevitably generated on the surface of plastic working material be equivalent to the degree of depth of 1/5th �� scope of 50 ��m. Refer to by the heat reduction process in hydrogen atmosphere it addition, remove oxide; Utilize the chemical treatments of the mixed liquor etc. of chloroazotic acid or Fluohydric acid. and nitric acid; Machinery removal based on cutting or grinding; Or their combination removes in processing the oxide skin(coating) on produced surface, this process is implemented after rolling process finishing.

Additionally, to the intensity in crystal diffraction face control carry out for the opposite face up and down of sheet material, namely at least 1 face for the ND face of Fig. 1 carries out, this be due to: as long as the arbitrarily one side of top and bottom is controlled, then molybdenum board material entirety will be made to produce secondary recrystallization by the heat treatment of more than 1700 DEG C, thus the mean diameter of the crystal grain in TD face or RD face is more than 15mm in plate cross section, i.e. Fig. 1.The distance additionally limitting distance plate surface is because it is found that secondary recrystallization is brought appreciable impact by the X-ray diffraction intensity in the region being equivalent to thickness of slab 1/5th from plate surface.

When to make the peak intensity in crystal diffraction face be above-mentioned condition, can be unclear in the concrete mechanism producing secondary recrystallization lower than conventional temperature, but the recrystallization phenomenon of crystal grain includes primary recrystallization and secondary recrystallization, described primary recrystallization is that rolling implemented by the crystal grain to molybdenum board material or the processing such as forging forms strain, is heated processing to it and causes that strain is open and is again formed for core with the strain produced by processing. Secondary recrystallization is to produce described primary recrystallization crystal grain gigantism and fit phenomenon, it is believed that the reason that phenomenon of secondary recrystallization brings the Mo for the present invention relates to considerable influence is: the state of the Mo before primary recrystallization, namely form the position of the core of recrystallization and be present in the peak intensity in crystal diffraction face and meet the region of above-mentioned condition.

Herein, sometimes only representing the X-ray diffraction intensity of the present invention as mentioned above with 1 face in the ND face of Fig. 1, this determines due to plastic working condition, for instance the condition such as the reversion of top and bottom during sheet fabrication in the sheet material of molybdenum carries out rolling processing. On the other hand, when top and bottom have been rolled equably, the two sides in ND face easily presents the X-ray diffraction intensity of the present invention.

It should be noted that, it is not absolutely required to the X-ray diffraction intensity in all regions being equivalent to 1/5th of whole of plate surface and meet above-mentioned condition, as long as at least some of of plate surface exists the part meeting above-mentioned condition, then can produce secondary recrystallization with this part for basic point.

Primary recrystallization temperature is normally due to the difference of processing conditions and more or less difference, but general at 1000 DEG C��about 1100 DEG C, and for the sheet material of the present invention, the same with conventional material is 1000 DEG C��about 1100 DEG C.

Fig. 4 B having illustrated, the ideograph of primary recrystallization tissue is convenient for reference. As long as the atmosphere non-oxidizing atmosphere for producing primary recrystallization is just not particularly limited. Such as can enumerate hydrogen, argon, vacuum atmosphere etc., it is also possible to for the atmosphere being made up of combinations thereof.

Then, in order to make molybdenum board material in the present invention produce secondary recrystallization, it is necessary at 1700 DEG C of heat treatments carried out above. This be due to: conventionally, when less than this temperature, for instance be difficult to when carrying out 10 hours heat treated for 1600 DEG C produce secondary recrystallization. It should be noted that the heat time heating time under 1700 DEG C of conditions needs 10 hours, if but reach more than above-mentioned temperature, then produce secondary recrystallization in the shorter time. Atmosphere when being additionally carried out heat treatment is the same with the situation of above-mentioned primary recrystallization.

When the molybdenum board material of the present invention being carried out heat treatment more than 1700 DEG C, the mean diameter of the crystal grain in plate cross section is preferably more than 15mm. This is because, it is to obtain the crystal particle diameter required for good resistance to creep properties. Additionally with the financial burden spent by treatment temperature and process time for reason in patent documentation 1, maximum crystal particle diameter is 150mm, if but use product of the present invention, it is possible to make crystal grain gigantism when relatively low temperature/short time, monocrystalline can also be formed according to condition. Even if it addition, the size of sheet material increases, if preparing it to be carried out the heating furnace of heat treatment size, then can the size of corresponding sheet material make secondary recrystallization after crystal particle diameter become big, therefore maximum crystal particle diameter is unrestricted.

It should be noted that average crystal particle diameter described herein is discussed further below the meansigma methods of situation: as it is shown on figure 3, for 1 test film, draw 3 parallel arbitrary lines in sheet material top and bottom, calculate the crystal particle diameter on respective line.

It should be noted that the Mo of the present invention is substantially unrestricted to size. The size of Mo is by manufacturing what the plastic working device such as device and heating furnace or rolling, forging, wire drawing etc. determined. As an example, can obtaining the Mo of the present invention in the test of the present inventor, it is the large-sized sheet material of long 1500mm, wide 1000mm, thick 20mm.

Embodiment

Hereinafter, based on embodiment, the present invention is further elaborated.

(embodiment 1 and comparative example 1)

Make molybdenum board material with various processing conditions, the resistance to creep properties etc. after the peak intensity in thickness of slab direction and the relation of secondary recrystallization temperature and secondary recrystallization has been evaluated. Concrete order is as described below.

Using purity is that 99.9 mass % and the molybdenum powder that granularity is 4 ��m that measured by Fsss method are as initiation material. This molybdenum powder is filled in rubber and utilizes CIP (cold isostatic press, ColdIsostaticPressing) with 2ton/cm²Pressure be pressed, carry out 10 hours sintering with 1800 DEG C in the hydrogen gas stream, thus obtaining wide 300mm, long 400mm and 2 pieces of sintered bodies that thickness is 20mm and 150mm. The relative density of the sintered body obtained respectively 94.2%, 94.4%.

This sintered body is heated after 20 minutes at 1500 DEG C, is repeatedly performed the rolling of 2��3 passages and the reheating of 1200 DEG C, finally gives the molybdenum board material that thickness of slab is 1.0mm, 1.5mm, 2.0mm, 3.0mm, 10mm, 20mm. In embodiments of the invention 1, the sheet material of thickness of slab 1.0mm��3.0mm is the sintered body that thickness is 20mm to be rolled and makes, and the sheet material of thickness of slab 10mm, 20mm is the sintered body that thickness is 150mm to be rolled and makes.

Herein, test portion for embodiment 1, the Reduction by rolling (=((thickness before rolling)-(thickness after rolling)) �� 100/ (thickness before rolling) unit %) of every 1 passage is set smaller than 20%, specifically 10%��19.8%.

Finally, utilizing chloroazotic acid to remove the oxide on surface after carrying out reduction treatment with 800 DEG C in hydrogen atmosphere, utilizing pure water to be carried out afterwards, thus obtaining the test portion of embodiment 1.

<X-ray diffraction>

Then, carry out X-ray diffraction analysis according to the following order test portion to obtaining, measure the peak intensity in thickness of slab direction.

First, use water-proof abrasive paper (No. #100��No. #1000) that the ND face (rolling surface) of test portion is carried out wet lapping, test portion after grinding is immersed in electrolyte (crossing chloric acid: ethanol=1:9), carry out the electrolytic polishing of 150 seconds with electric current 1A, test portion is ground to the thickness of slab direction degree of depth carrying out X-ray diffraction.

Then, utilize the X-ray diffraction device (RAD-2X) that Co., Ltd. Rigaku manufactures, use Cu pipe ball, with tube current be 30mA, tube voltage be 40kV, scanning speed: 1 degree of (deg)/min; Divergent slit: 1 degree (deg); Scatter slit: 1 degree (deg); Light inlet slot: 0.15mm; The condition measuring angle 2 ��=30 degree��120 degree (deg) carries out the X-ray diffraction of test portion, and the size of (110), (220) of the measurement result exported, the intensity in (211) face is compared. It should be noted that data obtained herein are the results obtained after the initial data measured being carried out background process, smoothing techniques automatically by device software and is removed K �� 2.

Then, again carry out above-mentioned grinding, test portion is ground to the thickness of slab direction degree of depth carrying out X-ray diffraction, carries out X-ray diffraction in this degree of depth.Until repeated multiple times carrying out aforesaid operations till the degree of depth of regulation, to it, change based on the peak intensity in the thickness of slab direction in the ND face of X-ray diffraction is measured every time.

Table 1 illustrates 1 example (sheet metal thickness is 1.5mm) of the change of the peak intensity in the thickness of slab direction in the ND face based on X-ray diffraction of obtained molybdenum board material, shown in Fig. 5, table 1 has been carried out the result of pictorialization.

[table 1]

According to table 1 and Fig. 5 it will be apparent that: the strength ratio of (211) near the central authorities of thickness of slab direction be higher than (110), (220), the intensity of (110), (220) is the value close to 0. Additionally in the region from 300 ��m of surface (being equivalent to 1/the 5 of thickness of slab), the intensity of (110), (220) is less than the intensity of (211). In other test portions of embodiment 1, the distribution of each crystal face is also same tendency.

It should be noted that texture is the state representated by the ideograph of Fig. 4 A.

Then, the composition of the test portion obtained is measured.

Specifically, use the luminescence of plasma analytical equipment ICPS-8100 that Shimadzu Seisakusho Ltd. manufactures that metal ingredient is measured. As gaseous impurity, O, C are measured, use the TC-600 that LECO company manufactures that O is measured respectively, use the WC-230 that LECO company manufactures that C is measured.

Its result is: the composition of test portion is made up of molybdenum and other inevitable impurity of more than 98.0 mass %. It should be noted that as inevitable impurity herein, it is Al, Ca, Cr, Cu, Fe, Mg, Mn, Ni, Pb, Si, Sn, Ti, Zr, Zn metal impurities and O, C gaseous impurity, removes the purity of these materials as molybdenum purity.

Obtain wide 300mm, long 400mm and 2 pieces of sintered bodies that thickness is 20mm and 150mm similarly to Example 1, after this sintered body is heated 20 minutes at 1500 DEG C, it is repeatedly performed the rolling of 2��3 passages and the reheating of 1200 DEG C, finally gives the molybdenum board material that thickness of slab is 1.0mm, 1.5mm, 2.0mm, 3.0mm, 10mm, 20mm. The Reduction by rolling of every 1 passage is set as 20%��23% herein. It should be noted that, in the same manner as in Example 1, the sheet material of thickness of slab 1.0mm��3.0mm is the sintered body that thickness is 20mm to be rolled and makes, and thickness of slab is the sheet material of 10mm, 20mm is the sintered body that thickness is 150mm is rolled and makes, thus obtaining the test portion of comparative example 1.

Using thickness of slab in above-mentioned comparative example 1 is the test portion of 1.5mm, measures the change of the X-ray diffraction intensity in thickness of slab direction in the same manner as in Example 1, obtains the result as shown in table 2 and Fig. 6.

[table 2]

As shown in table 2 and Fig. 6, for the test portion of comparative example 1, in this sheet material, on thickness of slab direction, the crystal diffraction face (110) in region from plate surface 1/5 or (220) respective peak intensity are more than (211).

Then, with 1600 DEG C��2200 DEG C, each test portion that embodiment 1 and comparative example 1 are obtained is carried out the heat treatment of 1 hour��the longest 10 hours in the hydrogen gas stream, the TD face (with reference to Fig. 1) of the sheet material after heat treatment is carried out structure observation, utilize above-mentioned segment method to calculate average crystal particle diameter, secondary recrystallization temperature is evaluated.

It should be noted that be there is primary recrystallization during reaching above-mentioned each temperature by each test portion that embodiment 1 and comparative example 1 are obtained, specifically there is primary recrystallization at 1000 DEG C��1100 DEG C.

In the mensuration of average crystal grain, the TD face of Fig. 1 is carried out structure observation, and calculates crystal particle diameter. For test film, respective sheet material is that 30mm cuts by length, by grinding/etching is adapted to observe crystallite dimension, and calculates crystal particle diameter by segment method. More specifically, as it is shown on figure 3,1 test film is drawn 3 parallel arbitrary lines in sheet material top and bottom, calculate the crystal particle diameter on respective line, be averaged the value average crystal particle diameter as this test portion.

But, the crystal particle diameter after secondary recrystallization is more than 1mm, and tissue morphology is the tissue morphology shown in the ideograph of Fig. 4 C, so being sometimes difficult to particular crystal particle diameter. Therefore, if the crystal particle diameter of more than 15mm, then all it is expressed as " more than 15mm ". Result is shown in Figure 7.

According to Fig. 7 it will be apparent that: for the test portion of embodiment 1, TD face Zone Full is carried out the heating of more than 1700 DEG C and at least 10 hours, so crystal particle diameter is more than 15mm, on the other hand, test portion for comparative example 1, when only thickness of slab is 1.0mm, by the heat treatment at 2000 DEG C, gigantism is to more than 15mm, if other test portions of comparative example 1 do not carry out the heating of 2200 DEG C, cannot obtain the crystal grain of more than 15mm. It addition, under 1600 DEG C of conditions, embodiment 1 and in comparative example 1 average crystal particle diameter be less than 100 ��m, there is not secondary recrystallization. It should be noted that without significant difference on any 3 lines that average crystal particle diameter is measured. Occur secondary recrystallization texture be similar in the C of Fig. 4 in mode scheme represent form.

It addition, for the test portion of embodiment 1, TD face is observed by the mensuration of the crystal particle diameter in molybdenum board material cross section, but on RD face, have also been obtained same tissue.

The rolling condition of molybdenum board material and crystal face etc. are not described by patent documentation 1; but that compare this as a result, it is possible to think described in the present embodiment by being heated and independently make whole comparative example 1 of the huge granulation of crystal grain with heat time heating time being the sheet material generally conforming to patent documentation 1 at 2200 DEG C. Namely, it is known that condition ratio similar to patent documentation 1, the test portion of embodiment 1 has carried out huge crystallization at low temperature.

Then, with the deflection of the stress test based on 1800 DEG C, the resistance to creep properties of the test portion of embodiment 1 and comparative example 1 is evaluated.

Specifically, first, carry out heating in 5 hours with 1800 DEG C of test films to embodiment 1 in the hydrogen gas stream so that it is secondary recrystallization, and be processed into and be of a size of wide 20mm �� long 150mm. It should be noted that employ the sheet material that thickness of slab is 1.0mm, 1.5mm, 2.0mm, 3.0mm, 10mm, 20mm. The test film of comparative example 1 is heated processing and being processed into the size of regulation similarly. All there is not secondary recrystallization in each test portion of comparative example 1.

Then, as shown in Figure 8, test film 1 is arranged on tungsten fixture 2 and 2 '. The distance of fixture 2 and 2 ' is 100mm, and the central part of the test film on fixture 2 and 2 ' is applied loading 3. Loading during for test, when when when during thickness of slab 1mm, loading is 125g, thickness of slab 1.5mm, loading is 280g, thickness of slab 2mm, loading is 500g, thickness of slab 3mm, loading is 1.1kg. Furthermore, it is contemplated that the safety of test, the loading at the trial of the sheet material of thickness of slab 10mm and 20mm is 12.5kg.

Then, when test film is applied described loading, grow the heating for 100 hours most with 1800 DEG C in the hydrogen gas stream, measure the deflection of test portion.As shown in Figure 8, deflection represents with the difference of the test film 1 before test and the position of the upper surface of the test film 1 ' after test, uses microcomputer (Microgauge) to measure. It should be noted that consider the safety of test, occur the sample of 20mm deformation in this moment abort, do not carry out the test when heat time heating time of longer time.

The deflection measured is shown in Figure 9. It should be noted that " stopping " in figure refers to owing to deflection reaches 20mm and abort.

As it is shown in figure 9, unrelated with thickness of slab, there is 20mm deformation in the test portion of comparative example 1 after 20 hours, and the test portion of embodiment 1 illustrates good resistance to creep properties almost not deforming after 100 hours. It addition, describe the data of the thickness of slab 2mm utilizing same test method and obtain in as the patent documentation 1 of prior art, compared with this result of the test, product of the present invention obtain equal above excellent results.

(comparative example 2)

To the sheet material that thickness of slab in the sheet material of embodiment 1 is 1.5mm by grinding from two surface removals until the region of to the degree of depth 1/5+50 ��m, the heat treatment of 1 hour Dao the longest 10 hours is carried out in the hydrogen gas stream with 1600 DEG C��2200 DEG C, the TD face (with reference to Fig. 1) of the test portion after heat treatment is carried out structure observation, calculate average crystal particle diameter by above-mentioned segment method, secondary recrystallization temperature is evaluated.

Its result is: the same with the test portion of comparative example 1, if above-mentioned sheet material does not carry out being heat-treated to 2200 DEG C, then will not produce the gigantism of the crystal grain that secondary recrystallization causes.

It is believed that this be due to: for the test portion of embodiment 1, in the region from two case depths 1/5, defining the core of starting point producing secondary recrystallization lower than conventional temperature.

Result according to above: in the region being equivalent to 1/5th degree of depth along thickness of slab direction from arbitrary surface at least 1 face of the opposite face up and down of molybdenum board material, the peak intensity in the crystal diffraction face in the parallel face of relative rolling direction is controlled, it is hereby achieved that the molybdenum board material with industrialness advantage as described below, compared with conventional art (patent documentation 1), secondary recrystallization can be produced in lower temperature, and resistance to creep properties is excellent.

Industrial applicibility

Above, describe the present invention based on embodiment and embodiment, but the present invention is not limited to above-mentioned embodiment.

To those skilled in the art, expecting that various variation or improvement example are natural within the scope of the invention, it it will be seen that these fall within the scope of the present invention.

Such as, above-mentioned embodiment and embodiment make molybdenum board material by rolling processing, it may also be the molybdenum board material obtained by Forgingother processing etc., as long as the peak in the X-ray diffraction face described in the mode of being carried out and embodiment controls, then its secondary recrystallization similarly can be made.

Additionally, in above-mentioned embodiment and embodiment, using tabular as the shape of molybdenum, even if being the shape beyond the sheet material of such as bar shape, recrystallization phenomenon is also essentially identical, if it is taken as that as the above-mentioned peak carrying out X-ray diffraction face controls, then it similarly can be made at low temperature secondary recrystallization. Under such circumstances, as long as the peak intensity being equivalent to the X-ray diffraction face in the region of 1/5th degree of depth of the diameter of bar along central shaft from bar surface meets above-mentioned condition.

It should be noted that, the present invention is used for high-temperature structural material and component materials, especially for constituting the wall of high temperature furnace or supporting the parts of other constituent materials, more specifically, for platen, heater, reflecting plate or as firing of using when the such securing member of bolt etc. constitutes the material of high temperature furnace main body or manufactures pottery, MIM (metal injection molded) sintered body such as product and rare earth element magnet uses backing plate.

It addition, the present invention can act as the parts of crystal growth stove, specifically such as aluminum is melted the parts constituting stove of crystal growth stove when manufacturing sapphire single-crystal; Or also serve as after due to secondary recrystallization deformation less and for stretching the parts of sapphire single-crystal.

Symbol description

Test film before 1 creep test

Test film after 1 ' creep test

2,2 ' creep test fixture

3 creep test loadings

Claims

1. a Mo, it is characterized in that, be equivalent to along thickness direction from surface gross thickness 1/5th the degree of depth region in, having part as described below at least partially: when carrying out X-ray diffraction mensuration, this part has crystal diffraction face (110) and (220) respective peak intensity region less than the peak intensity of (211).

2. Mo as claimed in claim 1, it is characterised in that molybdenum content is more than 98.0 mass %.

3. Mo as claimed in claim 1, it is characterized in that, this Mo has sheet material shape, sheet material opposite face up and down at least 1 face be equivalent to along thickness of slab direction far from surface thickness of slab 1/5th the degree of depth region in, having part as described below at least partially: when carrying out X-ray diffraction mensuration, this part has crystal diffraction face (110) and (220) respective peak intensity region less than the peak intensity of (211).

4. Mo as claimed in claim 2, it is characterized in that, this Mo has sheet material shape, sheet material opposite face up and down at least 1 face be equivalent to along thickness of slab direction far from surface thickness of slab 1/5th the degree of depth region in, having part as described below at least partially: when carrying out X-ray diffraction mensuration, this part has crystal diffraction face (110) and (220) respective peak intensity region less than the peak intensity of (211).

5. Mo as claimed in claim 1, it is characterized in that, this Mo has bar shape, be equivalent to along central axis direction from surface diameter 1/5th the degree of depth region in, having part as described below at least partially: when carrying out X-ray diffraction mensuration, this part has crystal diffraction face (110) and (220) respective peak intensity region less than the peak intensity of (211).

6. Mo as claimed in claim 2, it is characterized in that, this Mo has bar shape, be equivalent to along central axis direction from surface diameter 1/5th the degree of depth region in, having part as described below at least partially: when carrying out X-ray diffraction mensuration, this part has crystal diffraction face (110) and (220) respective peak intensity region less than the peak intensity of (211).

7. the Mo as described in any one of claim 1��6, it is characterised in that when the temperature more than 1700 DEG C has carried out heat treatment, the mean diameter based on segment method of the crystal grain in this Mo cross section is more than 15mm.

8. a Mo, it is characterised in that the Mo described in any one of claim 1��7 is thermally treated resulting in by the temperature that this Mo is more than 1700 DEG C, and the mean diameter based on segment method of the crystal grain in cross section is more than 15mm.

9. a heating furnace structure member, it is characterised in that this heating furnace structure member has the Mo described in any one of claim 1��8.

10. fire with backing plate for one kind, it is characterised in that this is fired has the Mo described in claim 3 or 4 with backing plate.