A kind of preparation method of structural steel forgingTechnical field
The present invention relates to a kind of preparation method of structural steel forging, particularly relate to a kind of forging preparation method who saves the energy, improves stock utilization, reduces production costs, improves working conditions.
Background technology
Producing at present automobile forging manufacturing technique method, is to become one section one section with high quality round bar sawing mostly, then in stove, is heated to 1200 DEG C of left and right, carries out forging molding after coming out of the stove on forcing press.This production technology stock utilization is low, consumes energy high, and production efficiency is low, and cost is high, and the production cycle is long, relatively requires high to direct labor's technical merit.
Summary of the invention
The object of this invention is to provide the forging preparation method that a kind of energy consumption is low, steel utilization ratio is high, production cost is low, working condition is good.
For achieving the above object, the technical solution adopted in the present invention is: a kind of preparation method of structural steel forging, and employing steel scrap is raw material, smelts into high-quality molten steel at middle frequency furnace, then on hydraulic press, carries out liquid forging, and 1200 DEG C of left and right demouldings; Upsetting on forcing press, base, finish forging, trimming immediately after the demoulding, detailed step is as follows:
S1, select materials: choose the steel scrap that is applicable to this technique, do raw material;
S2, intermediate frequency furnace are smelted: the steel scrap of choosing is put into intermediate frequency furnace and smelt into high-quality molten steel;
S3, liquid forging: the molten steel of having smelted is poured in the air pressure casting holding furnace that is full of argon gas and is incubated; Again molten steel casting in holding furnace is carried out to liquid forging in liquid forging machine mould, before casting, mould will be preheated to 150～200 DEG C, when the demoulding immediately 1200 DEG C of left and right time of blank temperature;
S4, forcing press die forging: the high temperature blank after the demoulding is sent into upsetting in forcing press, base, finish forging, trimming immediately.
Preferred: after the trimming technology of step S4, to carry out following steps: S5, immediate quenching: the temperature of forging stock after utilizing trimming, carry out Quenching Treatment.
Preferred: the forging obtaining by step S1 to S5 is carried out to temper.
Aforementioned arbitrary structures can be further preferred: in described S1 step, the steel scrap of choosing is carbon structural steels or low-alloy structural steel steel scrap.
Aforementioned arbitrary structures can be further preferred: in described S2 step, after smelting molten steel, carry out Argon purification, improve Molten Steel Cleanliness.
Aforementioned arbitrary structures can be further preferred: the mould in described step S3 adopts the composite die that internal layer is high temperature alloy, is cooled with circulating water mould in casting cycle, by regulating cooling water flow, pressure that mold temperature is controlled in 400 DEG C.
The present invention has following beneficial effect: the present invention utilizes molten steel heat energy, carries out liquid forging, in high temperature (forging temperature) demoulding, carry out immediately forging molding, immediate quenching (while needs adopt), above-mentioned technical process, centre does not need to heat again and can complete forging and produce.Utilize technique, as long as change molten steel chemical composition and mould geometry, size can be produced the forging such as gear, axle class, forked type class.Owing to being directly connected to production cost the service life of liquid-state forging die, preferably adopt composite die, i.e. internal layer high temperature alloy, the general material in outside, modified rear use; Be cooled with circulating water mould, by regulating cooling water flow, pressure that mold temperature is controlled in 400 DEG C.Above-mentioned way can improve die life greatly; Calcining temperature, coordinate with finish forging temperature, can not be too low or too high; Final forging temperature height, calcining temperature should reduce, on the contrary calcining temperature should improve; While starting to forge, all moulds all will be preheated to 150～200 DEG C; After the liquid forging demoulding, the calendering of blank ratio is answered > 3.
The invention has the advantages that:
1, stock utilization of the present invention is high, consumes energy low (in the middle of except tempering, not needing to heat) again, and with short production cycle, production cost is low.Can realize automated production, improve working conditions.
2, above technical process is by some units, is combined on a flow production line and completes whole production process.Between unit (operation), robotic arm, conveyer belt transmit blank automatically.
Novel technique and the contrast of existing technology:
| ? | Existing technology | Novel technique | Novel technique effect |
| Cost of raw and processed materials | High quality round bar expense is high | Steel scrap → molten steel expense is low | Reduce by 15% left and right |
| Utilization rate of raw materials | Steel utilization ratio 85% left and right | Molten steel Utilization rate 95% left and right | Improve 10% left and right |
| Energy consumption | Heating steel billet, blanking power consumption | Do not heat, utilize the distortion of molten steel heat | More than forging economize on electricity 300 degree per ton |
| Production efficiency | Be subject to human factor control large | About productive temp 50 seconds | Be enhanced about more than once |
| Production cost | Production cost is high | Production cost is low | Reduce more than 20% |
| Labor cost | Forger operation | 80% left and right robotic arm | Reduce by 80% left and right |
| To operator's technical requirement | High | Low | Skilled worker |
| Investment | Low | High | Initial cost is higher |
Detailed description of the invention
A preparation method for structural steel forging, employing steel scrap is raw material, smelts into high-quality molten steel at middle frequency furnace, then on hydraulic press, carries out liquid forging, and 1200 DEG C of left and right demouldings; Upsetting on forcing press immediately after the demoulding, base, finish forging, trimming, immediate quenching (just using while needs), detailed step is as follows:
S1, select materials: choose the steel scrap that is applicable to this technique, do raw material, the steel scrap of choosing is carbon structural steels or low-alloy structural steel steel scrap, this scrap resources is abundant.Steel scrap in this step, by inspection, to determine its chemical composition contamination, and then is chosen the raw material of applicable steel scrap as this processes forging.
S2, intermediate frequency furnace smelt: the steel scrap of choosing is put into intermediate frequency furnace and smelt into high-quality molten steel (high-quality molten steel refers to that the chemical composition contamination of molten steel all reaches the requirement that will prepare forging, meet standard GB/T/T3077-1999 requirement, scrap smelting becomes after molten steel, the chemical composition of molten steel is carried out to real-time inspection, be up to the standards and be high-quality molten steel; The chemical composition of passing through containing quantity not sufficient of disqualified upon inspection is added, the excessive chemical composition of the content mode such as dilute is adjusted, until the chemical composition of molten steel reaches requirement, become high-quality molten steel), the chemical composition of molten steel requires material with auto parts and determines.After smelting molten steel, carry out Argon purification, improve Molten Steel Cleanliness.
S3, liquid forging: the molten steel of having smelted is poured in the air pressure casting holding furnace that is full of argon gas and is incubated; Again molten steel casting in holding furnace is carried out to liquid forging in liquid forging machine mould, before casting, mould to be preheated to 150～200 DEG C, in casting cycle, be cooled with circulating water mould, by regulating cooling water flow, pressure that mold temperature is controlled in 400 DEG C, when the demoulding immediately 1200 DEG C of left and right time of blank temperature; Mould in this step adopts composite die, it is internal layer high temperature alloy, high temperature alloy is preferably heated die steel 3W23Cr4 or H13, the general material in outside, general material is preferably steel No. 45, modified rear use, is cooled with circulating water mould in casting cycle, by regulating cooling water flow, pressure that mold temperature is controlled in 400 DEG C.
S4, forcing press die forging: the high temperature blank after the demoulding is sent into upsetting in forcing press, base, finish forging, trimming immediately;
S5, immediate quenching: after trimming technology, select whether part to be quenched according to the requirement that will prepare forging, quenching step is utilized the temperature of forging stock after trimming, carry out Quenching Treatment, the temperature of forging stock after trimming, generally 850 DEG C of >, utilize this temperature can carry out Quenching Treatment.
According to the parameter needs of part, the forging obtaining by above-mentioned steps S1 to S5 is carried out to temper.Temper processing technology is used prior art means, and the temperature of tempering is selected according to the requirement that will prepare forging.
Be described further with steering knuckle forging below: knuckle material: 40C (GB3077-1999)
Part weight: 20Kg.
One, technical process: operation is just use while needing in steel scrap → intermediate frequency furnace smelting → air pressure holding furnace → liquid forging → upsetting → base → finish-forging → trimming → (immediate quenching) → (tempering) bracket.
Detailed process process is shown in S1～S5.
Two, a production line main production equipments: 1 ton of intermediate frequency converter 3 (3 refining 2), one of 3 tons of air pressure quantitative casting holding furnace, 3 of 400 t hydraulic press, one of each one, 200 tons clipping press of electric screw press (630 tons, 1000 tons, 1600 tons), heat treatment tank (cooling medium temperature control circulation).
Test of many times testing result below:
Chemical component table (%)
| ? | C | Si | Mn | P | S | Cr | Cu |
| Required value | 0.37-0.44 | 0.17-0.37 | 0.50-0.80 | ≤0.035 | ≤0.035 | 0.80-1.10 | ≤0.3 |
| Measured value | 0.38-0.44 | 0.19-0.35 | 0.56-0.75 | ≤0.025 | ≤0.025 | 0.85-1.05 | ≤0.2 |
Mechanical property detects table (condition of heat treatment: modified)
The knuckle forging of producing according to above-mentioned technical process, through Dissection test repeatedly repeatedly, the requirement that chemical composition and mechanical property all can be up to state standards.
More than describe preferred embodiment of the present invention in detail.Should be appreciated that the present invention is the mature technology that utilizes this area: intermediate frequency furnace smelting, liquid forging, forcing press die forging, immediate quenching are combined in and on a production line, complete forging and produce; Round rolling, saw material, heating process are reduced.The object that reaches energy-saving and cost-reducing, reduces costs, improves stock utilization, realizes automated production, improves working conditions.Those of ordinary skill just can design according to the present invention be made many modifications and variations without creative work.Therefore, all technical staff in the art, all should be in by the determined protection domain of claims under this invention's idea on the basis of existing technology by the available technical scheme of logical analysis, reasoning, or a limited experiment.