CN105251922A - Square steel forging and pressing process - Google Patents

Abstract

The invention relates to a square steel forging and pressing process. The square steel forging and pressing process comprises the following steps that (1) a square steel heating curve graph is drawn, the horizontal ordinate of the square steel heating curve graph indicates the heating time, and the vertical coordinate indicates the heating temperature; (2) square steel is heated according to the square steel heating curve graph obtained in the step (1); and (3) upsetting treatment and drawing-out treatment are conducted on the heated square steel. By means of the square steel forging and pressing process, the process accuracy is high, the surface quality of the square steel is good, and a casting process is simple and reliable.

Description

Square steel forging process

Technical field

The invention belongs to metal forging field, relate to a kind of square steel forging process.

Background technology

In forging process, forging and stamping can shrinkage cavity and porosity in densification or seam as cast metal tissue, space, the defect such as bubble and crackle, again can crystal grain thinning and breaking clip foreign material, thus obtain certain forging flow lines tissue.In actual production, normal according to Production requirement, various forging, such as mainly for the production of various machine parts that is important, that bear heavy load or blank, as all needed distortion such as its jumping-up pulling, reaming, bending, drawing in the process such as the main shaft of lathe and gear, the connecting rod of internal combustion engine, the suspension hook of crane, in forging process, due to the reason of each side such as oxidation and cooling meat of metal surface under high temperature, forging precision is not high, surface quality is bad, in addition the restriction of forging processability of product structure, forging is usually only as the blank of machine parts.Forge hot pressure is the forging and stamping carried out more than metal recrystallization temperature, improves the plasticity that temperature can improve metal, is conducive to the inherent quality improving workpiece, makes it not easy to crack.High-temperature can also reduce the resistance of deformation of metal, reduces the tonnage of required metal forming machinery.But forge hot pressure operation is many, and workpiece accuracy is poor, and surface is not bright and clean, and forging easily produces oxidation, decarburization and scaling loss.

Summary of the invention

The object of the invention is to the problem overcoming the soft state copper covered steel wire percentage elongation deficiency of producing in traditional handicraft, disclose a kind of produce simple, the production technology of percentage elongation and the high soft state copper covered steel wire of yield rate.

In order to realize foregoing invention object, the present invention adopts following technical scheme:

The production technology of soft state copper covered steel wire, comprises the following steps: successively

(1) drawing, carries out peeling off descale by steel wire mother metal, then is dried through peracid electrolysis, washing, boronation, high-frequency heating by the steel wire after descale, finally the steel wire after oven dry is drawn to diameter 1.8-2.4mm;

(2) high tempering, steel wire after drawing is put into vacuum tempering furnace and carries out high-temperature heat treatment, between temperature 780-830 DEG C, heat time controls between 5-6 hour, then be incubated 5-6 hour, be then cooled to 560-600 DEG C, control cool time between 12-13 hour, open air-cooler to be again cooled to about 300 DEG C and to come out of the stove, control cool time between 2-3 hour;

(3) electro-deposition pre-treatment, be that the steel wire hydrochloric acid solution of 1.8-2.4mm carries out pickling by diameter, remove the oxide skin on steel wire surface, and then wash, remove pickle residual in steel wire surface acid-washing operation, steel wire sodium carbonate after washing is carried out alkali neutralization, removes upper track washing step and do not wash down clean pickle completely;

(4) sour electrolysis, carries out sour electrolysis to the steel wire sulfuric acid solution after electro-deposition pre-treatment, removes the oxide skin on steel wire surface further, and activates steel wire surface;

(5) wash, remove pickle residual in last process;

(6) pretreatment electro-deposition, carries out pretreatment electro-deposition by the steel wire after washing by potassium hydroxide and copper sulphate mixed liquor, generates copper covered steel wire;

(7) wash, remove the solution that last process is residual;

(8) thick process electro-deposition, carries out the thick process electro-deposition of further sulfate by the copper covered steel wire after washing;

(9) wash, remove the electrodeposit liquid of remained on surface in last process;

(10) anti-oxidation, the copper covered steel wire antioxidant after washing is carried out anti-oxidation process;

(11) dry, the copper covered steel wire after anti-oxidation process is carried out drying process;

(12) drawing, is drawn to diameter between 0.50-0.70mm by dried copper covered steel wire;

(13) wash, the copper covered steel wire after drawing is washed, remove the grease on copper covered steel wire surface;

(14) anti-oxidation process, carries out anti-oxidation process by the copper covered steel wire antioxidant after washing;

(15) ammonolysis craft high tempering: 1. ammonolysis craft stage, first ammonia destruction furnace is warming up to about 500 DEG C, insulation makes whole body of heater be heated evenly, then continue to be warming up to 650-670 DEG C and send ammonia, open air bleeding valve simultaneously and water is put in air bleeding valve outlet, when temperature arrives 800-820 DEG C, flame is crocus substantially, there is no and drip, is now the mixture of N2 and H2 in ammonia destruction furnace; 2. the high tempering stage, be filled with by N2 and the H2 mixture decomposited and be equipped with in the vacuum tempering furnace of copper covered steel in ammonia destruction furnace, allow in whole tempering furnace and be full of N2 and H2, temperature is between 780-830 DEG C, and temperature retention time 5-6 hour; Close vacuum tempering furnace, with stove cooling 7.5-8 hour, then air cooling makes in-furnace temperature close to room temperature, is evacuated by stove, pours N2,

Make stove pressure valve show 0MPa, copper covered steel finished product is taken out in blow-on.

More preferably, described step (3) electro-deposition pre-treatment adopts the hydrochloric acid solution of volume ratio between 40%-60% to carry out pickling, and step (4) middle volume ratio carries out sour electrolysis at the sulfuric acid solution of 15%-25% to steel wire.

As preferably, the copper layer thickness in described step (8) after thick process electro-deposition is between 0.002-0.024mm.

As preferably, the 1-1.5 that first heated up by ammonia destruction furnace in described step (15) is little of temperature about 500 DEG C, is then incubated 1.5-2 hour, when temperature rises to about 750 DEG C, in the igniting of air bleeding valve exit, observation flame color and outlet go out with or without water droplet; Stove air cooling time is between 25-30 hour.

As preferably, described steel wire mother metal is H08 steel wire, produces, eliminate polishing process by above-mentioned skill, avoids work hardening to a certain degree, and compared with mild steel M6, H08 steel wire price is low, and therefore production cost is low.

As preferably, described steel wire mother metal is mild steel M6, and mild steel M6 stable material quality, impurity is few, good-extensibility.

As preferably, described boronation immerses in borax soln by steel wire, and borax soln temperature, between 75-85 DEG C, makes steel wire surface form boronation film, borax soln temperature is lower than 75 DEG C, the boronation film quality formed is bad, and in follow-up drawing process, wire drawing oil easily embeds in boronation film, Steel Wire Surface is made to turn black or occur black splotch, borax soln temperature is higher than 85 DEG C, then energy consumption is high, and specifically borax soln temperature is more than 1.5 times of normal level higher than the energy consumption needed for 85 DEG C.

As preferably, in the described whole high tempering stage, ammonolysis craft continues to carry out, until body of heater is cooled to room temperature, opens the explosion protection system being connected to tempering furnace steam vent place simultaneously, in the igniting of steam vent place, prevents the hydrogen of discharging from contacting with air to produce and explode.

As preferably, the diameter of described steel wire mother metal is 6.5mm or 5.5mm.

Adopt the production technology of the soft state copper covered steel wire of technique scheme, its advantage is: 1, in step 1 by the steel wire after descale through sour electrolysis, washing, boronation, drawing again after high-frequency heating oven dry, compared with former technique, reduce drawing number of times, reduce production cost, by producing boronation film on steel wire surface after boronation, metal steel wire can be reduced contact with the direct of mould, extend die life, drawing speed can be improved, reduce the loss of material, obtain uniform and smooth finished surface, boronation film is soluble in water simultaneously, be convenient to the cleaning on follow-up steel wire surface, 2, high tempering can eliminate the work hardening of steel wire, crystal grain thinning, reduces fragility, improves toughness, can make the wire drawing wet goods of steel wire remained on surface all because high temperature carbonization forms loose oxygen simultaneously

Change skin, be easy to follow-up pickling and wash away oxide skin, solve the steel wire layer that often occurs and the bad problem of layers of copper adhesion, yield rate is high; In high tempering process, after temperature retention time, first power-off is little of temperature 560-600 DEG C with stove cooling 12-13, thermal stress can be reduced like this, prevent steel wire inside from cracking, then open air-cooler cooling and within 2-3 hour, be quickly cooled to about 300 DEG C and come out of the stove, can save time like this, open the secondary oxidation that air-cooler cooling avoids steel wire simultaneously, it also avoid the oxidation of flue; 3, ammonolysis craft tempering process is adopted, containing a large amount of hydrogen in vacuum tempering furnace, and hydrogen has reduction, the function of light reduced anneal, therefore copper covered steel surface-brightening can be made after tempering, so without the need to carrying out polishing to the copper covered steel after tempering, therefore can by copper covered steel wire direct drawing to 0.50-0.70mm, the copper covered steel finished product of surface-brightening is produced into by ammonolysis craft tempering process, percentage elongation >=10%, eliminate follow-up polishing process, avoid the impact of work hardening again on percentage elongation, finished product percentage elongation is improved.In sum, by percentage elongation >=10% of above-mentioned explained hereafter copper covered steel wire out, the percentage elongation of the copper covered steel wire produced than traditional tempering process at least can be enhanced about more than once.

Detailed description of the invention

The invention provides a kind of square steel forging process, this square steel forging process comprises the following steps:

1) prepare square steel heating curves figure, the abscissa of described square steel heating curves figure is the heat time, and ordinate is heating-up temperature:

1.1) choose different steel grades and obtain himself heat characteristic;

1.2) according to step 1.1) heat characteristic of different steel grades that obtains determine different steel grade enter furnace temperature, initial forging temperature and tapping temperature;

1.3) different steel grade heat time when forging and pressing is determined;

1.4) take abscissa as the heat time, ordinate is the heating curves figure that heating-up temperature draws different steel grade.

2) according to step 1) square steel heats by the square steel heating curves figure that obtains:

2.1) charging temperature 50 degree;

2.2) be rapidly heated to 900 ° ± 10 °, described in the amplitude that is rapidly heated be per hour between 50 ° ~ 100 °; The present invention, when embody rule, according to the difference of steel grade, can finely tune the amplitude be rapidly heated to some extent, and such as 55 ° per hour, 75 ° or 98 ° etc. can;

2.3) be warming up at a slow speed 1250 ° ± 10 °, the described amplitude heated up at a slow speed is per hour not higher than 50 °;

2.4) 40 ~ 60 minutes are incubated;

2.5) come out of the stove.

3) square steel after heating is carried out pier slightly to process with pulling, the thick number of times at least twice with pulling out process of pier is carried out to the square steel completing heating.

Steel ingot concentric reducer in use, first amputates by the present invention, according to above-mentioned heat treatment step by Heating Steel Ingots to proper temperature, first carry out the pulling of small deformation amount, can loosen by seam material internal, then it is thick to carry out pier, pulling, can improve forging ultrasound examination percent of pass.

More than show and describe general principle of the present invention and principal character and advantage of the present invention.The technical staff of the industry should understand; the present invention is not restricted to the described embodiments; what describe in above-described embodiment and description just illustrates principle of the present invention; without departing from the spirit and scope of the present invention; the present invention also has various changes and modifications, and these changes and improvements all fall in the claimed scope of the invention.Application claims protection domain is defined by appending claims and equivalent thereof.

Claims (4)

1. a square steel forging process, is characterized in that: described square steel forging process comprises the following steps:

1) prepare square steel heating curves figure, the abscissa of described square steel heating curves figure is the heat time, and ordinate is heating-up temperature;

2) according to step 1) square steel heats by the square steel heating curves figure that obtains;

3) square steel after heating is carried out pier slightly to process with pulling.

2. square steel forging process according to claim 1, is characterized in that: described step 1) specific implementation be:

1.1) choose different steel grades and obtain himself heat characteristic;

1.2) according to step 1.1) heat characteristic of different steel grades that obtains determine different steel grade enter furnace temperature, initial forging temperature and tapping temperature;

1.3) different steel grade heat time when forging and pressing is determined;

1.4) take abscissa as the heat time, ordinate is the heating curves figure that heating-up temperature draws different steel grade.

3. square steel forging process according to claim 2, is characterized in that: described step 2) specific implementation be:

2.1) charging temperature 50 degree;

2.2) be rapidly heated to 900 ° ± 10 °, described in the amplitude that is rapidly heated be per hour between 50 ° ~ 100 °;

2.3) be warming up at a slow speed 1250 ° ± 10 °, the described amplitude heated up at a slow speed is per hour not higher than 50 °;

2.4) 40 ~ 60 minutes are incubated;

2.5) come out of the stove.

4. the square steel forging process according to claim 1 or 2 or 3, is characterized in that: described step 3) in the square steel completing heating carried out to the number of times at least twice of the thick and pulling process of pier.