CN102794613A

CN102794613A - Fusion welding method for heating steel-cast iron interface rapidly

Info

Publication number: CN102794613A
Application number: CN2012103130084A
Authority: CN
Inventors: 崔国栋; 杨川; 李人宪; 高国庆
Original assignee: Southwest Jiaotong University
Current assignee: Southwest Jiaotong University
Priority date: 2012-05-04
Filing date: 2012-08-30
Publication date: 2012-11-28

Abstract

The invention discloses a fusion welding method for heating a steel-cast iron interface rapidly. The fusion welding method comprises the following processing steps: (1) the surfaces of two workpieces are treated; (2) the surfaces of the two workpieces are in close contact with each other, induction heating rings are sleeved outside the two workpieces to ensure that the binding faces of the two workpieces are placed in the centers of the induction rings, and the induction heating rings are separated from the two workpieces by a quartz tube; (3) induction heating is started to rapidly heat the binding part of the two workpieces to 1200-1300 DEG C, and when the cast iron workpiece is partially fused, the heating is stopped; and (4) a steel-cast iron workpiece treated by step (3) is subjected to corresponding heat treatment, so that a target finished product of the steel-cast iron workpiece is obtained. The fusion welding method has the advantages that the process is controllable, the operation is simple, and the equipment generality is high.

Description

The fusion welding method of a kind of steel-cast iron interface Fast Heating

Technical field

The invention belongs to manufacturing of novel metal structural material and compound welding technology field.

Background technology

Steel, cast iron are to use structural metallic materials the most widely; Steel, the cast iron of the different trades mark have different performances and purposes; Along with development of science and technology; A kind of steel of the trade mark, cast iron are difficult to satisfy the serviceability requirement of diversification, and this just need carry out Combined Processing with two kinds of different steel and cast irons of performance, reach best performance indications.On complex method, multiple complex methods such as vacuum brazing, laser weld, continuous casting have been arranged, on engineering, obtained widely and used.The only suitable thin walled welds that the distortion that but the cost that these complex methods have process high, that have is wayward, have is big, have etc.; Limited range of application; Particularly for the comparatively complicated workpiece of some shapes; Like shield cutter, axle, wheel, bearing holder (housing, cover), gear etc., also not preferably method carry out compound preparation, therefore the research of novel steel-cast iron composite preparation process also has wide space and huge market prospects.

Summary of the invention

Above deficiency in view of prior art the objective of the invention is, and obtains a kind of steel-cast iron compound preparation method fast, makes it to overcome the shortcoming of prior art, reaches best composite effect.The objective of the invention is to realize through following means.

The fusion welding method of a kind of steel-cast iron interface Fast Heating forms steel part and ironcasting and is connected, and comprises following processing step:

(1) joint face of the steel workpiece desiring to be connected and cast iron part is carried out cleaning surfaces and handle, make surfacing smooth with polishing; (2) the steel workpiece is overlapped two surface of the works closely contact on the cast iron part; Induction heating circle is linked in outside two workpiece, makes the binding face of two workpiece be placed on the centre of induction coil, separate with quartz ampoule between induction heating circle and two workpiece; (3) open eddy-current heating, make the applying position of two workpiece quickly heat up to 1200 ℃～1300 ℃, after cast iron part is in local melting, stop heating; (4) steel-cast iron part after (3) processing is accomplished corresponding heat treatment, obtain purpose steel-cast iron part finished product.

Compare with other method, method of the present invention have process control easily, simple to operate, the distortion little, low cost and other advantages.Adopt superaudio or Intermediate Frequency Induction Heating Equipment to belong to mature technology in this process, simple to operate, control easily.1200 ℃～1300 ℃ heating makes the cast iron smelting that contacts with steel, and the cast iron and the steel at other position do not melt, and stops heating, and steel sinks under the effect of gravity, and the cast iron of fusing can link together steel and unfused cast iron, forms the connection of steel-cast iron.In the preparation process, can adopt low low carbon steel substrate of cost and white iron to carry out compound melting welding, can guarantee the wearability of workpiece after compound, can guarantee the toughness plasticity of matrix again, the expanding application scope with improve service life.Adopt the mild steel-white iron composite sample of this method Combined Processing; Can fuse fully at compound position and to be one,, avoid defectives such as slit, oxidation, hole with other compared with techniques; Increased substantially bond strength, can guarantee that again the performance of two kinds of materials own is not destroyed simultaneously.Compound back adopts the normalizing stress removing can also further improve the bond strength and the performance at compound place.

Description of drawings is following:

Fig. 1 is the principle schematic of the inventive method;

Fig. 2 is the metallograph (metallographic structure Fig. 4 % nitric acid alcohol corrosion 100 of junction, compound back *) of the junction, the compound back of 20 steel-white iron of the inventive method preparation.

The specific embodiment

At first; Compound steel, cast iron sample are carried out in preparation; And the cleaning surfaces processing is carried out on plane that will be compound; Remove surface impurity and defectives such as surface and oil contaminant, oxide skin, decarburized layer, and on abrasive paper for metallograph, processing is polished on the plane that will be combined with each other, guarantee that two planes that will be combined with each other are smooth, smooth; Then, the closely contact of surface that respectively two samples will be combined with each other does not stay the slit to be placed on the centre of induction coil, separates with quartz ampoule between induction coil and the sample; At last; Adopt superaudio or Frequency Induction Heating, the compound position of steel, cast iron sample is quickly heated up between 1200 ℃～1300 ℃ simultaneously, the cast iron that contacts with steel melts; The cast iron and the steel at other position do not melt; At this moment stop heating, the cast iron of fusing can be with molten steel and cast iron do not link together formation steel-cast iron composite; According to the serviceability requirement, can carry out the heat treatment of different process to the sample after compound, eliminate stress, reach best result of use.

Embodiment 1

Select two length to be 100mm respectively, diameter is 20 steel, the white cast-iron sample of 20mm, and the end face of the sample that will be combined with each other polishes with abrasive paper for metallograph, removes impurity, defectives such as greasy dirt, oxidation; Respectively two samples are put into induction heating circle, the end face that be combined with each other is closely contacted, and be in the centre of induction heating circle, adopt the superaudio eddy-current heating, separate with quartz ampoule between induction heating circle and the sample; After putting well; Begin heating, maximum temperature is heated to the white cast-iron that contacts with 20 steel and melts in the 1mm aspect about 1250 ℃; The white cast-iron at other position and 20 steel do not melt; At this moment stop heating, the cast iron of fusing can link together not molten steel and cast iron, forms the compound connection of 20 steel-white cast-iron.500 ℃ * 1 hour tempering heat treatment of the sample that gained connects, joint face stress is eliminated good, connects firm.

Embodiment 2

Adopt external diameter 30mm; Internal diameter 15mm; The 20CrMnTi sample of the circular spheroidal graphite cast-iron sample of thickness 15mm and same geomery; Adopt instance 1 same method that two circular samples are combined with each other, be heated to 880 ℃ of insulations then and put into 280 ℃ salt bath insulation 10 minutes after 20 minutes immediately, can obtain the intact spheroidal graphite cast-iron of globular graphite, mild steel composite sample with Isothermal Quenching Structure.

Experiment through series finds that steel-compound preparation method of cast iron Fast Heating adopts superaudio or Frequency Induction Heating that good effect is arranged.Experiment finds that also steel workpiece adopts mild steel, medium carbon steel, high-carbon steel or micro alloyed steel, with cast iron materials white cast-iron, casting pig, making up one by one of spheroidal graphite cast-iron good effect is arranged all, can guarantee that obvious change does not take place the form of graphite in the cast iron simultaneously.

Claims

1. the fusion welding method of steel-cast iron interface Fast Heating forms steel part and ironcasting and is connected, and comprises following processing step:

(1) joint face of the steel workpiece desiring to be connected and cast iron part is carried out cleaning surfaces and handle, make surfacing smooth with polishing; (2) the steel workpiece is overlapped on the cast iron part, two surface of the works closely contact; Induction heating circle is linked in outside two workpiece, makes the binding face of two workpiece be placed on the centre of induction coil, separate with quartz ampoule between induction heating circle and two workpiece; (3) open eddy-current heating, make the applying position of two workpiece quickly heat up to 1200 ℃～1300 ℃, after cast iron part is in local melting, stop heating; (4) steel-cast iron part after (3) processing is accomplished corresponding heat treatment, obtain purpose steel-cast iron part finished product.

2. the fusion welding method of the steel according to claim 1-cast iron interface Fast Heating is characterized in that, said steel sample can be mild steel, medium carbon steel, high-carbon steel or micro alloyed steel, and cast iron materials can be white cast-iron, casting pig, spheroidal graphite cast-iron.

3. the fusion welding method of the steel according to claim 1-cast iron interface Fast Heating is characterized in that, said steel-compound preparation method of cast iron Fast Heating adopts superaudio or Frequency Induction Heating.

4. the fusion welding method of the steel according to claim 1-cast iron interface Fast Heating is characterized in that said corresponding heat treatment can be adopted the method for normalizing, annealing or isothermal hardening.

5. the fusion welding method of the steel according to claim 1-cast iron interface Fast Heating is characterized in that, said local melting is meant that the following 0.5mm～3mm in cast iron interface is molten state.