CN104532027A - Production technology of tube blank alloy CN617 for ultra-supercritical thermal power unit - Google Patents

Abstract

The invention discloses a production technology of a tube blank alloy CN617 for an ultra-supercritical thermal power unit. The production technology realizes industrial trial-manufacture and satisfies hot-working use requirements. Vacuum induction furnace smelting comprises the following steps of material blending, material preparation, vacuum-pumping, charging, power supplement, charging, total melting, stirring, standing, component adjustment and pouring. The production technology utilizes a unique chemical composition ratio, trace elements and reasonable technological parameters. The production technology has the advantages that 1, an industrial production design is realized, in other words, an appropriate smelting method is selected so that good hot-working performances of chemical components and a finished product ingot are guaranteed, and the tube blank alloy CN617 has good performances and a wide purpose, and 2, at present, the CN617 alloy is in a laboratory test stage and cannot be used in industrial production, and the production technology provided by the invention can be successfully used in small-scale industrial production and has batch production feasibility.

Description

A kind of ultra supercritical coal-fired unit pipe alloy CN617 production technique

Technical field

The invention belongs to nickel-base high-temperature alloy material field, relate to a kind of ultra supercritical coal-fired unit pipe alloy CN617 production technique.

Background technology

At present, coal fired power generation, must capacity of installed generator structure progressively to new forms of energy and clean energy adjustment in China's main energy sources generated energy nearly 80%.The power supplying efficiency of 700 DEG C of ultra-supercritical power generation technologies will be increased to 50%, and every kilowatt-hour coal consumption can reduce nearly 70 grams again, and Carbon emission reduces 14%, is the road for development of clean combustion of coal generation technology.2010, China set up 700 DEG C of ultra-supercritical power generation technology Innovation Alliances of country, started " PCR700 " plan.A lot of key parts of 700 DEG C of ultra-supercritical coal-fired units need use nickel-base high-temperature alloy material, for this reason, unit of allied member has carried out the development work of the high-duty boiler tube material that 700 DEG C use, in early stage screening material process, Technical Committee of alliance material group determines on the 617 alloy bases of recommending in European Union and improves material composition and performance.CN617 alloy development difficulty is industrial technological design (selecting suitable smelting process), ensure the hot workability of composition and finished ingot; Pertinent literature describes composition range and the performance perameter of 617 alloys, and a wider range of parameter is general cannot specific in actual production; The smelting process that external pertinent literature proposes 617 alloys is a lot, comprise vacuum induction to smelt, or vacuum induction is smelted and added esr, which kind of smelting technology bring adverse influence all can to the hot-work of finished ingot because the proportioning of composition is improper and process parameters design is unreasonable.

Summary of the invention

The present invention discloses a kind of ultra supercritical coal-fired unit pipe alloy CN617 production technique, and object is proportioning and process parameters design by adopting vacuum induction smelting and reasonable component, realizes Industry trial-production, reaches hot-work working conditions.

Pipe alloy CN617 produces total technological process:

Starting material preparation → vacuum induction furnace smelting → chemical analysis → metal electrode tack → consumable electrode vacuum furnace remelting → chemical analysis → alloy pig that strips off the skin strips off the skin → alloy pig diffusion annealing → surface inspection → payment.

For achieving the above object, following technical scheme is formulated to vacuum induction furnace smelting:

1. technical process: prepare burden → get the raw materials ready → find time → feed → divide → pour into a mould (see figure 1) to electricity → charging → fine melt → stirring → standing → furnishing;

Work simplification is following four steps (Fig. 2 comprises 2-4 step):

(1) prepare burden and get the raw materials ready;

(2) vacuumize, feed, to electricity, fine melt, above step is series-operation, is the process of material;

Refining period process: stir, leave standstill, furnishing divides;

(4) water injecting electrode.

2. concrete technology measure

1. alloy CN617 chemical composition should meet table 1 and specifies

Table 1 %

Alloy Ni-Cr19-Co12-Mo9 chemical composition should meet table 2 and specify;

Table 2 %

2. the various amounts returning steel, alloy material required for smelting are calculated according to alloying constituent control overflow.Select the materials such as metallic nickel, cobalt metal, chromium metal, metal molybdenum, metallic aluminium, metal titanium, Graphite Electrodes, wherein metallic nickel and cobalt metal will anticipate the film on surface; Returns melting process in advance, chemical composition is accurate, and the starting material entering stove keep clean, without greasy dirt;

3. vacuumize, ensure vacuum tightness≤10Pa; Charging by batches enters stove, expects after loading the first batch of material to electrification;

4. loading sequence according to returns after first pure metal, and will not add with electrode containing Nb metal and returns simultaneously;

5. power system startup utilizes the induction coil of body of heater to heat, and starting material is heated and starts fusing;

6. stir 10min ~ 15min after fine melt, leave standstill 12min ~ 20min, thermometric, samples I analysis ingredient and gas content; Gas content should meet O :≤20 × 10 ^-6, N:(100-200) × 10 ^-6if exceed regulation, need Heating temperature at 1500 DEG C ~ 1520 DEG C, carry out induction and stir, stir 10min, static 5min, the cycle need determine according to gasometry result;

7. refining period, vacuum degree control was at 1Pa ~ 5Pa, and was no less than 90min, thermometric T2, and adjusting component C, Mo, Cr, CO, add AL, Ti, stirred 10min, left standstill;

8. argon filling 3000Pa: sampling II, inching composition C, AL, Ti, and add B, stir 10min, thermometric T3, get two sample, temperature reaches 1460 DEG C ~ 1490 DEG C and can tap;

9. pour into a mould: moderate temperature, adjustment crucible angle rotating electrode mould, makes depositing funnel relative with mould, and control pouring speed also ensures time of feeding.

Inventive point of the present invention and beneficial effect :

1. CN617 alloy smelting technology is without relevant documents and materials, the external Inconel617 alloy produced describe only smelting process: the smelting process introduced as ASTM or SAE etc. is that vacuum induction or vacuum induction add electroslag, international pioneering for the smelting process of comforting steel and produce highly purified ultra supercritical blank tube material CN617 alloy, particularly the chemical composition of CN617 alloy has originality, make a big difference in the interpolation of chemical composition proportioning and trace element with external Inconel617 alloy, CN617 alloy is that modified version has good performance and purposes widely accordingly, 2. CN617 alloy is the laboratory test stage before this, and without Industry trial-production, present small-scale industrialized producing technology is successfully manufactured experimently, and has obtained the ability of batch production, for thermal power station of China autonomy-oriented material is laid a good foundation.

Accompanying drawing explanation

Fig. 1 is CN617 alloy vacuum induction furnace smelting process flow sheet;

Fig. 2 is CN617 alloy vacuum induction furnace smelting process sequence diagram.

Embodiment

Below in conjunction with accompanying drawing 2 and specific examples, the present invention is described in more detail.

The technological measure that embodiment 1, embodiment 2 and embodiment 3 perform jointly:

1. alloy CN617 chemical composition is allocated into and control;

2. the various amounts returning steel, alloy material required for smelting are calculated according to alloying constituent control overflow.Select the materials such as metallic nickel, cobalt metal, chromium metal, metal molybdenum, metallic aluminium, metal titanium, Graphite Electrodes, wherein metallic nickel and cobalt metal will anticipate the film on surface; Returns melting process in advance, chemical composition is accurate, all enter the starting material of stove keep clean, without greasy dirt;

3. vacuumize, ensure vacuum tightness≤10Pa; Charging by batches enters stove, expects after loading the first batch of material to electrification;

4. loading sequence according to returns after first pure metal, and will not add with electrode containing Nb metal and returns simultaneously;

5. power system startup utilizes the induction coil of body of heater to heat, and starting material is heated and starts fusing;

6. stir 10min ~ 15min after fine melt, leave standstill 12min ~ 20min, thermometric, samples I analysis ingredient and gas content;

7. refining period, vacuum degree control was at 1Pa ~ 5Pa, and was no less than 90min;

8. argon filling 3000Pa: sampling II, inching composition; Temperature reaches 1460 DEG C ~ 1490 DEG C and can tap;

9. pour into a mould: moderate temperature, adjustment crucible angle rotating electrode mould, makes depositing funnel relative with mould, and control pouring speed also ensures time of feeding.

Embodiment 1

Produce CN617 alloy, heat (batch) number: 13242200062, crucible capacity: 6 tons, ingot weight: 5448kg.

1. CN617 alloying constituent is allocated into and control by table 3,

Table 3 %

6. fine melt state thermometric ensures that temperature is at 1520 DEG C, oxygen level 12 × 10 ^-6nitrogen content: 127 × 10 ^-6;

7. refining period, the chemical composition according to fine melt adjusts, and makes chemical composition close to target value, as following table 4,

Table 4 %

8. adding Fe-B after filling Ar gas makes B element according to 0.0035% target control, does not entirely receive according to finished product result.Chemical composition analytical results as table 5,

Table 5 %

9. pour into a mould: temperature is at 1480 DEG C, and the duration of pouring is 8min.

Embodiment 2

Produce CN617B alloy, heat (batch) number: 14,240 170142, crucible capacity: 6 tons, ingot weight: 5448kg.

1. CN617 alloying constituent is allocated into and control by table 3;

3. vacuumize, by low vacuum to condition of high vacuum degree (10Pa to 2Pa), this process is exitted because starting material melt and is vented, and vacuum tightness constantly fluctuates, and adopts gas change in sampling analysis gas monitor molten steel;

[4. loading sequence: Ni plate, Metal Cr, Co plate, metal M o etc.;

6. fine melt was through 7 hours fine melts, fine melt temperature 1510 DEG C;

8. tapping temperature 1490 DEG C is poured into a mould;

Each stage chemistry composition with receive situation in table 6,

Table 6 %

Finished product gas: H:1.3 × 10 ^-6, O:10 × 10 ^-6, N:20 × 10 ^-6.

Embodiment 3

Produce Ni-Cr19-Co12-Mo9 alloy forging material, heat (batch) number 12,242 210342, crucible capacity: 1 ton, the heavy 976kg of ingot.

As shown in Figure 1,

1. Ni-Cr19-Co12-Mo9 alloying constituent is allocated into and control by table 2;

3. vacuumize vacuum tightness reach 8Pa and along with raw-material fusing constantly exit, degassed to fine melt;

4. loading sequence: be followed successively by Ni plate, master alloy, Metal Cr, Mo, Co;

6. after fine melt, condiment adds Ta simultaneously, stirs 20min, and fine melt gas obtains result O:7 × 10 ^-6, N:85 × 10 ^-6, stir degassed in refining process, gas result O:10 × 10 ^-6, N:20 × 10 ^-6; Chemical composition analytical results is as table 7;

9. Pouring control pouring speed, the duration of pouring 2min, teeming temperature, at 1480 DEG C, pours into a mould an electrode,

Table 7 %

C	Mn	Si	S	P	Cr	Mo	Co	Al	Ti	Fe
											0.07	0.01	0.05	0.001	0.001	19.24	9.51	11.51	1.25	1.40	0.54

Claims (3)

1. a ultra supercritical coal-fired unit pipe alloy CN617 production technique, total technological process:

Starting material preparation → vacuum induction furnace smelting → chemical analysis → metal electrode tack → consumable electrode vacuum furnace remelting → chemical analysis → alloy pig that strips off the skin strips off the skin → alloy pig diffusion annealing → surface inspection → payment, it is characterized in that:

Described vacuum induction furnace smelting alloy CN617 chemical composition should meet table 1 and specify:

Table 1 %

Alloy Ni-Cr19-Co12-Mo9 chemical composition should meet table 2 and specify;

Table 2 %

The concrete technology flow process of described vacuum induction furnace smelting: prepare burden → get the raw materials ready → find time → feed → divide to electricity → charging → fine melt → stirring → standing → furnishing → pour into a mould;

Work simplification is following four steps:

(1) prepare burden and get the raw materials ready;

(2) vacuumize, feed, to electricity, fine melt, above step is series-operation, is the process of material;

Refining period process: stir, leave standstill, furnishing divides;

(4) argon filling, cast;

Described batching calculates the various amounts returning steel, alloy material required for smelting according to alloy composition and control overflow;

Described materials such as selecting metallic nickel, cobalt metal, chromium metal, metal molybdenum, metallic aluminium, metal titanium, Graphite Electrodes of getting the raw materials ready, wherein metallic nickel and cobalt metal will anticipate the film on surface; Returns melting process in advance, chemical composition is accurate, all enter the starting material of stove keep clean, without greasy dirt;

Describedly to vacuumize, ensure vacuum tightness≤10Pa; Charging by batches enters stove, expects, then feed after loading the first batch of material to electrification;

Described loading sequence according to returns after first pure metal, and will not add with electrode containing Nb metal and returns simultaneously;

Namely described electricity of giving is that power system startup utilizes the induction coil of body of heater to heat, and starting material is heated and starts fusing;

Stir 10min ~ 15min after described fine melt, leave standstill 12min ~ 20min, sample I analysis ingredient and gas content; Gas content is analyzed, and it should meet O :≤20 × 10 ^-6, N:(100 ~ 200) × 10 ^-6; If exceed regulation, need Heating temperature at 1500 DEG C ~ 1520 DEG C, carry out induction and stir, stir 10min, static 5min, the cycle need determine according to gasometry result;

Described refining period, vacuum degree control was at 1Pa ~ 5Pa, and was no less than 90min, thermometric T2, and adjusting component C, Mo, Cr, CO, add AL, Ti, stirred 10min, left standstill;

Described argon filling 3000Pa, sampling II, inching composition C, AL, Ti, and add B, stir 10min, thermometric T3, get two sample;

Described cast: temperature reaches 1460 DEG C ~ 1490 DEG C and can tap, adjustment crucible angle rotating electrode mould, makes depositing funnel relative with mould, and control pouring speed also ensures time of feeding.

2. a kind of ultra supercritical coal-fired unit pipe alloy CN617 production technique according to claim 1, is characterized in that: described vacuum induction furnace smelting CN617 alloying constituent is allocated into and control by table 3,

Table 3 %

Described fine melt state thermometric ensures that temperature is at 1520 DEG C, oxygen level 12 × 10 ^-6nitrogen content: 127 × 10 ^-6;

In described refining period, the chemical composition according to fine melt adjusts, and makes chemical composition close to target value, as following table 4,

Table 4 %

Adding Fe-B after the described Ar of filling gas makes B element according to 0.0035% target control, does not entirely receive according to finished product result;

Chemical composition analytical results as table 5,

Table 5 %

Described teeming temperature is at 1480 DEG C, and the duration of pouring is 8min.

3. a kind of ultra supercritical coal-fired unit pipe alloy CN617 production technique according to claim 1, is characterized in that:

Described alloying constituent is allocated into and control by table 2;

Table 2 %

Described vacuumize reach 8Pa and along with raw-material fusing constantly exit, degassed to fine melt; Described loading sequence: be followed successively by Ni plate, master alloy, Metal Cr, Mo, Co;

After described fine melt, condiment adds Ta simultaneously, stirs 20min, and fine melt gas obtains result O:7 × 10 ^-6, N:85 × 10 ^-6;

Stir degassed in described refining process, gas result O:10 × 10 ^-6, N:20 × 10 ^-6;

Described Pouring control pouring speed, the duration of pouring 2min, teeming temperature, at 1480 DEG C, pours into a mould an electrode, chemical composition analytical results as table 7,

Table 7 %

C Mn Si S P Cr Mo Co Al Ti Fe 0.07 0.01 0.05 0.001 0.001 19.24 9.51 11.51 1.25 1.40 0.54

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