CN87101512A

CN87101512A - The technology and the device of the little distortion integral quenching of thin-wall part

Info

Publication number: CN87101512A
Application number: CN 87101512
Authority: CN
Inventors: 高智敏
Original assignee: Individual
Current assignee: Individual
Priority date: 1987-03-11
Filing date: 1987-03-11
Publication date: 1988-09-21

Abstract

A kind of heat-treatment technology method and device that is suitable for the little distortion integral quenching of thin-wall part adopts the quenching tank with toroidal membrane, uses saturated aqueous oil as quenchant.Use quenching workpiece of the present invention can reduce quenching strain, improve workpiece quality, improve the qualification rate of product, need not tempering after the quenching, simple and easy to do.

Description

The invention belongs to the heat treatment quenching process method and the device of steel part.

Producing distortion when thin-walled and complex-shaped steel workpiece integral quenching is the difficult problem of thermal treatment process.Immerse in the oil through giving heating earlier with oil-quenched steel part, in the initial stage of quenching, form the oil vapour film at workpiece surface, the oil gas film hinders the thermal conduction of workpiece, and the heat radiation of workpiece surface is carried out in uneven process of cooling, the distortion of the workpiece that causes quenching.

For addressing this problem, the common practice is to adopt whipping appts in quenching tank.German patent application DE3037639 proposes in fluid medium in the particularly oily medium to use agitator and nozzle in order to improve cooling conditions, and the strong agitation fluid medium destroys the formation of oil gas film, to guarantee the quenching quality.But to thin-walled or baroque steel part, violent stirring itself will cause the distortion of part.

The objective of the invention is to provide the processing method and the device of the little distortion integral quenching of a kind of thin-wall part.Use the present invention and can reduce the workpiece quenching strain, improve the quenching quality, improve the qualification rate of product.

The present invention is achieved in that the fluid medium that is used to quench adopts wet oil, and so-called wet oil is to feed tap water or cooling circulating water in machine oil.As quenchant, workpiece is heated to quenching temperature and insulation when the workpiece phase transformation is finished with wet oil, immerses in the wet oil, do vertical movement up and down, treat to take out when workpiece temperature is chilled to the martensitic transformation starting point air cooling.When workpiece immersion wet oil is quenched in scorching hot waiting, just produce " blast " phenomenon immediately, the generation of this phenomenon is owing to contain the effect of water in the oil, this " blast " that produces can explosion workpiece formed oil gas film when quenching, guarantee that workpiece evenly cools off, thereby reduce the distortion of workpiece when quenching significantly.The quenching of workpiece is carried out in quenching tank, and quenching tank is the cell body of a steel, and there is a water inlet pipe on cell body top and has the annular spray pipe of aperture, and water shoot is arranged at the bottom of cell body, and the bore of water shoot should be greater than the water inlet pipe bore.One deck toroidal membrane is arranged in the cell body, and toroidal membrane is by the welding of reinforcing bar and cell body, and the bore of toroidal membrane is less than annular spray pipe, and in the bottom of annular spray pipe.First water filling tap water or recirculated cooling water in the quenching tank, the water surface will be higher than quenching tank bottom discharge mouth, injects machine oil then, and pasta is higher than toroidal membrane top.The toroidal membrane lower end is higher than the interfacial layer of water and oil.The degree of depth of wet oil is done vertical movement up and down and is remained in the moisture oil reservoir next definite according to the size of maximum quenching workpiece when quenching with the assurance workpiece.In quenching process, tap water or the recirculated cooling water aperture by annular spray pipe flows out, and drops down in the oil continuously along the inwall of quenching tank.The workpiece that in the toroidal membrane zone, quenches, with wet oil heating in the toroidal membrane zone, the wet oil proportion that is heated part reduces, and then upwards floats; The hot wet oil in the toroidal membrane outside is by water cooling, and proportion increases, and then sinks, and so just having formed is the wet oil automatic circulating system that need not additionaling power of boundary with the toroidal membrane.The effect of this system is to guarantee that the water in the wet oil always is in state of saturation; Reducing the temperature that wet oil constantly raises when quenching, relatively is the most effective heat exchange method with using various cooling tubes.Tap water or recirculated cooling water pass heated wet oil, sink to bottom land, discharge from water shoot, and the flow of tap water or recirculated cooling water will remain on when quenching wet oil, and must not to form foam excessive.Directly interior with the flowing into groove water of toroidal membrane protection workpiece contacts, and avoids producing distortion because of the rapid cooling in part.

Use the present invention and be suitable for all with oil-quenched workpiece with use oil-quenched operation.

The concrete structure of invention is provided by following embodiment and accompanying drawing thereof.

Fig. 1 is a quenching tank structural representation of the present invention;

Fig. 2 is the partial enlarged drawing of annular conduit of the present invention;

Fig. 3 uses impeller head disk parts drawing of the present invention;

Fig. 4 is the sectional view of Fig. 3 along the A-A line.

Below in conjunction with Fig. 1～4, describe the concrete device and the working condition that propose according to the present invention in detail.

According to Fig. 1, this device comprises cell body 3, water inlet pipe and annular spray pipe 1, toroidal membrane 4, rising pipe 2 and reinforcing bar 5; Wherein toroidal membrane 4 is fixing with cell body 3 welding by reinforcing bar 5, and toroidal membrane 4 bottoms are higher than cell body 3 bottom surface 200mm, and toroidal membrane 4 upper ends are lower than cell body 3 top 200mm; Annular spray pipe 1 is in the outer ring of toroidal membrane 4 and be higher than toroidal membrane 4 top 50mm; Rising pipe 2 is in the bottom of cell body 3, and rising pipe 2 water outlet height are for to count 0.8 times that approximates the wet oil degree of depth from moisture oil-water boundary.Inject tap water or recirculated cooling water to cell body 3 earlier during application, the water surface is higher than cell body 3 bottom 100mm, injects machine oil then, and pasta is higher than toroidal membrane 4 top 20mm, and tap water drops down in the machine oil in a steady stream along the inwall of cell body 3.It is as follows to be with impeller head disk (Fig. 3) quenching in toroidal membrane 4 zone of quenching tank that example specifies:

The impeller head disk is a part complex-shaped, that wall approaches, very easily is out of shape when quenching, and material is 40Cr(SAE5140).This part is heated to 840 ℃, grill thoroughly the back and be incubated half an hour, make it after the complete austenitizing, taking-up is quenched in the wet oil, do vertical movement up and down, vexed " roaring " sound is arranged when workpiece is quenched into wet oil, treat that this growl reaches the martensitic transformation starting point when reducing to faint.Take out air cooling after lasting 30 seconds.Test 200, through check hardness＞HRc41; Distortion＜0.06mm/500mm, qualification rate 100%, microstructure are ferrite+bainite+martensite.Because the phase transformation volumetric expansion, thereby produce structural stress during quenching, and the specific volume of ferrite and bainite is little than martensite all, so this quenching technology is little than the structural stress of quenching into martensitic technology fully and being produced.They come in every shape of ferrite, bainite, martensite because the partial molal volume effect also can correspondingly reduce structural stress, so thermal stresses and structural stress when quenching all are reduced to minimum limit, therefore can reduce workpiece deformation to greatest extent.Owing to the mixture that is organized as after quenching, so need not tempering.

This microstructure be specially adapted to the to withstand shocks part of grinding, it is the leading grinding of resisting external force with martensite, and ferrite and bainite play shock absorption as martensitic substrate to the impact of external force.With the impeller head disk that the present invention handles, work-ing life＞1000 hour.

Claims

1, a kind of processing method that is suitable for the little distortion integral quenching of thin-wall part, it is characterized in that quenchant adopts the wet oil that continuously adds tap water or recirculated cooling water in oil, workpiece is heated to quenching temperature and insulation when the workpiece phase transformation is finished, immerse in the wet oil, do vertical movement up and down, treat to take out when workpiece temperature is chilled to the martensitic transformation starting point air cooling.

2, a kind of device that is suitable for the little distortion integral quenching of thin-wall part, it is characterized in that quenching tank is made of the annular spray pipe 1 that has aperture on cell body 3, water inlet pipe and the tube wall, rising pipe 2, wherein toroidal membrane 4 is by reinforcing bar 5 and cell body 3 welding, and annular spray pipe 1 bore is greater than toroidal membrane 4 and above toroidal membrane 4.