CN1613579A

CN1613579A - Guiding blade of electric slag casting dissimilar steel water turbine

Info

Publication number: CN1613579A
Application number: CN 200410050554
Authority: CN
Inventors: 赵芳欣; 陈瑞; 李宝东; 于波; 张瑛洁; 王景成; 郝学卓
Original assignee: Shenyang Research Institute of Foundry Co Ltd
Current assignee: Shenyang Research Institute of Foundry Co Ltd
Priority date: 2004-10-09
Filing date: 2004-10-09
Publication date: 2005-05-11
Anticipated expiration: 2024-10-09
Also published as: CN1265917C

Abstract

A guide vane of water turbine is composed of a short axle, a flap body and a long axle, and is made up by electroslag casting process. It features that its short axle and flap body are made of the consumable electrode of low-carbon (or ultralow-carbon) stainless martensite steel and its long axle is made of the consumable electrode of other material. Its advantages are low cost, precise size and high quality.

Description

Electroslag casting dissimilar steel guide vanes of water turbine

(1) technical field

The present invention relates to a kind of technology that adopts the guide vanes of water turbine that the electroslag casting process manufacturing is made up of at least two kinds of materials.

(2) background technology

Along with the rapid raising of high speed development of national economy and living standards of the people, the demand of the energy is increased day by day.Wherein electric power is one of most important energy.And water power provides one of main path of electric power.The generating set water turbine of hydropower station installation at present, the lobe body portion of its key part stator is worked under water, require material to have high-strong toughness, wear resistance and corrosion resistance and corrosion fatigue resistant performance, therefore stator adopts the Low Carbon Martensite Stainless Steel material to make mostly at present, and it represents the trade mark is ZG06Cr13Ni4Mo.This material price costliness.Whole stator is made with Low Carbon Martensite Stainless Steel, will improve the overall cost of water wheels unit greatly.In fact the weight of guide vane body branch only accounts for about half of stator weight, and the major axis of stator part is not worked under water, only plays carry-over moment and supporting role, and the requirement of mechanics far below the lobe body, be there is no need to adopt Low Carbon Martensite Stainless Steel.But up to now, electroslag casting guide blade integral body is continued to use single Low Carbon Martensite Stainless Steel always, and this has caused bigger waste undoubtedly.

The method of making stator at present mainly contains:

1, sand mold is whole makes.This manufacture method is to make the main method of stator at present both at home and abroad.The stator that this method produces easily produces defectives such as shrinkage cavity, crackle in castingprocesses.

2, the lobe phantom is pressed into shape or a sand mold casting shaping and an axle assembly welding.The stator complex procedures that adopts this method to produce, the production cycle is long, and easily produces casting flaw.

3, solid forging stator.This processing method only is applicable to the manufacturing small guide blade usually.

4, electroslag casting guide blade.The stator that adopts this method to produce, its stator minor axis, lobe body, major axis are same material, cost height, waste resource.

(3) summary of the invention

Purpose of the present invention provides and a kind ofly meets the requirement of various water turbine use technology, and quality height, stator that price is low.

Another technical problem that the present invention will solve provides a kind of method by the integrally formed manufacturing stator of dissimilar steel.

The technical scheme that adopts is:

Electroslag casting dissimilar steel guide vanes of water turbine, constitute by stator minor axis, guide vane body and stator major axis, stator minor axis and guide vane body adopt the Low Carbon Martensite Stainless Steel consumable electrode, and the stator major axis adopts other turbine material consumable electrode, makes an one-piece construction by electroslag casting.That is: the stator minor axis is that Low Carbon Martensite Stainless Steel minor axis, guide vane body are Low Carbon Martensite Stainless Steel lobe body, and the stator major axis is other turbine material major axis, and the stator minor axis, and guide vane body, stator major axis are an one-piece construction.

Above-mentioned stator minor axis also can be made by electroslag casting by other turbine material consumable electrode.

The electrode composition of above-mentioned Low Carbon Martensite Stainless Steel guide vane body can adopt the composition shown in the table 1.

The electrode composition of above-mentioned stator minor axis and major axis can adopt the composition shown in the table 2.

Table 1 lobe body is shaped with electrode composition quality mark (%)

Comprise W, V

C Si Mn S P Cr Ni Mo Cu remarks

The residual element total amount

≤ 0.07≤1.0≤2.0≤0.04≤0.04 8.0～18.0 3.0～8.0≤2.0≤4.0≤1.0 all the other be Fe

The electrode composition massfraction (%) of the table 2 and the lobe body and function electrode similarities and differences

Comprise W, V

C Si Mn S P Cr Ni Mo Cu remarks

The residual element total amount

≤ 0.4≤1.0≤2.0≤0.04≤0.04≤18.0≤8.0≤2.0≤4.0≤1.0 all the other be Fe

A kind of manufacture method of stator comprises following technological process:

1, produces down crystallizer and last crystallizer, i.e. trussell and bottom mold by the stator design specification.The crystallizer material can be selected copper or steel for use.

2, consumable electrode is selected for use.Guide vane body electrode composition sees Table 1.The major axis electrode composition sees Table 2.But the composition of stator minor axis electrode option table 1, but the also composition of option table 2.

3, electroslag casting process.The technology founding dissimilar steel guide vanes of water turbine of electroslag casting guide blade routinely.

The present invention has following advantage:

1, metal quality is good.The metal purity height, dense structure, composition is even, any surface finish;

2, process stabilizing.The solidified structure may command, quality and performance reproducibility height;

3, blank dimension is accurate, can reduce amount of finish;

4, equipment is simple, and is easy to operate, saves operations such as moulding, no rising head, lumber recovery height, yield rate height.Except the combination of electrodes of need with differing materials, all the other technologies and single-material electroslag casting guide blade technology are in full accord, do not need to increase new operation and frock.

5, cost is low, and comparing cost with the electroslag casting guide vanes of water turbine of being made by single Low Carbon Martensite Stainless Steel material has reduction by a relatively large margin, can save a large amount of Low Carbon Martensite Stainless Steels.

(4) description of drawings

Fig. 1 is the crystallizer and the technological process synoptic diagram of electroslag casting guide blade.

Fig. 2 is ZG06Cr13Ni4Mo-20SiMn bimetal stator synoptic diagram (welded bonds is ZG06Cr13Ni4Mo with a left side, and welded bonds is with the material of the right side for beginning to melt from the 20SiMn electrode).

The drawing reference numeral explanation:

1 for minor axis, 2 for the guide vane body, 3 for major axis, 4 for consumable electrode, 5 for slag bath, 6 for metal pool, 7 for stator solidified part, 8 for crystallizer, 9 for base plate, 10 for welded bonds.

(5) embodiment

A kind of stator, the long 990mm of its major axis, the big end Φ of major axis 255mm, major axis small end Φ 198mm, the long 780mm of guide vane body, wide 450mm, the long 175mm of stator minor axis, Φ 180mm.Guide vane body and minor axis adopt Low Carbon Martensite Stainless Steel ZG06Cr13Ni4Mo consumable electrode, and the stator major axis adopts 20SiMn forged steel consumable electrode, makes an integrally-built stator (see figure 2) by electroslag casting.

ZG06Cr13Ni4Mo Low Carbon Martensite Stainless Steel consumable electrode composition sees Table 3, and the composition of 20SiMn forged steel consumable electrode sees Table 4.

Table 3 ZG06Cr13Ni4Mo electrode composition massfraction (%)

C Si Mn S P Cr Ni Mo Cu W V remarks

Surplus master

0.045 0.56 0.55 0.030 0.02 13.70 4.60 0.68 0.22 0.07 0.02

To be Fe

Table 4 20SiMn forged steel electrode composition massfraction (%)

C Si Mn S P Cr Ni Mo remarks

0.15 0.60 1.20 0.025 0.02 0.21 0.17 0.08 surplus is mainly Fe

Adopt welding process to connect the dissimilar steel electrode.The technology founding dissimilar steel stator of electroslag casting guide blade routinely.

According to the order founding stator of minor axis → lobe body → major axis, be the boundary with stator major axis welded bonds 10, comprise that the composition of lobe body one side is as shown in table 5, major axis small end end composition is as shown in table 6.

Table 5 is the composition quality mark (%) that the boundary comprises lobe body one side with the welded bonds

C Si Mn S P Cr Ni Mo remarks

0.04 0.45 0.53 0.015 0.016 13.73 4.60 0.65 surplus is mainly Fe

The composition quality mark (%) of table 6 major axis small end end

C Si Mn S P Cr Ni Mo remarks

0.146 0.59 1.18 0.016 0.016 0.28 0.19 0.085 surplus is mainly Fe

Compare with the electroslag casting guide blade that adopts single ZG06Cr13Ni4Mo material preparation, minor axis and lobe body adopt ZG06Cr13Ni4Mo in this example, and major axis adopts 20SiMn, and cost reduces by 30%.

Claims

1, electroslag casting dissimilar steel guide vanes of water turbine, stator is made of stator minor axis (1), guide vane body (2) and stator major axis (3), it is characterized in that stator minor axis (1) and guide vane body (2) adopt low-carbon (LC) or Mo ultralow-carbon martensitic stainless steel consumable electrode, stator major axis (3) adopts other turbine material consumable electrode, makes an one-piece construction by electroslag casting; The stator minor axis also can adopt other turbine material consumable electrode.

2, electroslag casting dissimilar steel guide vanes of water turbine according to claim 1, the composition that it is characterized in that described low-carbon (LC) or Mo ultralow-carbon martensitic stainless steel electrode and shaping rear guide vane corresponding section, massfraction, %:C≤0.07, Si≤1.0, Mn≤2.0, S≤0.04, P≤0.04, Cr=8.0～18.0, Ni=3.0～8.0, Mo≤2.0, Cu≤4.0, residual element total amount≤1.0 that comprise W, V, surplus are Fe.

3, electroslag casting dissimilar steel guide vanes of water turbine according to claim 1, the composition that it is characterized in that described other turbine material electrode and shaping rear guide vane corresponding section, massfraction, %:C≤0.4, Si≤1.0, Mn≤2.0, S≤0.04, P≤0.04, Cr≤18.0, Ni≤8.0, Mo≤2.0, Cu≤4.0, residual element total amount≤1.0 that comprise W, V, surplus are Fe.