CN102861860A - Cold upsetting manufacturing process for valve seat - Google Patents

Abstract

The invention relates to a cold upsetting manufacturing process for a valve seat. The cold upsetting manufacturing process comprises the following steps of: wiredrawing a bar, annealing, removing films, performing surface lubrication, performing forward extrusion, performing cold upsetting for forming and the like. The cold upsetting process has the advantages that metal extruded at room temperature is fine in crystalline grains, and the level of grain size is over 6 levels; and the production efficiency is improved greatly, and the quality of products is stable and reliable.

Description

Valve seating cold-heading manufacturing process

Technical field

The present invention relates to a kind of valve seating manufacturing process, particularly a kind of valve seating cold-heading manufacturing process.

Background technology

The kind of valve seating in the market is a lot, is widely used on motorcycle, automobile, but all is to adopt traditional cold punching processing basically.The defectives such as traditional processing method is efficient lowly, energy consumption is excessive, equipment investment is excessive.Valve seating is engine air valve device, and valve seating is had very high requirement of strength, simultaneously the metallographic of product is required high (grain size number is 6 grades), the valve seating that conventional method is made, and price is high, and the delivery cycle is long.

Traditional technique is: cold headers striking adobe → annealing → epithelium → cold-punching molding.This mode of production inefficiency, per tour only can be produced about 10000 of blanks, equipment, cutter investment excessive (needing altogether mould 2 cover 4W RMB, 1 30WRMB of cold headers, 2 60W RMB of punch press).

Summary of the invention

Goal of the invention: the purpose of this invention is to provide that a kind of production efficiency is high, steady quality and the high valve seating cold-heading manufacturing process of intensity.

Technical scheme: a kind of valve seating cold-heading manufacturing process, described cold heading technique may further comprise the steps:

A) bar wire drawing;

B) annealing: adopt pit type annealing furnace to vacuumize and inflated with nitrogen protection annealing, the monolateral degree of depth of annealing rear oxidation decarburization is less than or equal to 0.1 millimeter, and material hardness is HB113-120 after the annealing;

C) peeling film: remove the oxide skin that the bar surface produces in the step b annealing process;

D) surface lubrication: the blank among the step c is carried out oil removing, pickling, washing, phosphatization processing, air-cooled and saponification processing;

E) just crowded: adopt the hydraulic press of 2000KN to push, extruding force is 60T, in the bar section runout error 0.05;

F) cold-heading molding: adopt the cold headers of 500KN to carry out cold-heading, in the taper hole error 0.03, in the surface roughness 1.6,0.1 millimeter of product axiality, cold-heading speed 〉=60/minute.

The described annealing heating rate of step b is less than 150 ℃/h, and cooling rate is less than 50 ℃/h; Forvacuum exhausts at every turn and is filled with nitrogen, and its pressure is more than or equal to 0.01MPa; The annealing metallographic structure is the F+P ball, and rank is the 4-6 level.

The described surface lubrication of steps d may further comprise the steps:

A) electrochemical deoiling: blank is dropped into the sodium silicate solution of NaOH, 60～80g/L sodium carbonate, 25～80g/L sodium phosphate and the 10～15g/L of 60～100g/L, treatment temperature 〉=85 ℃, 15～25 minutes processing times;

B) mobile clear water is washed;

C) pickling: blank is dropped into pickling in the sodium chloride solution of the sulfuric acid of 120-180g/L and 8-10g/L, pickling temperature is 65-75 ℃, and pickling time is 5-10 minute;

D) clear water that flows is washed: be in order to prevent that the pickle that is adsorbed on blank surface from bringing in the lower road Phosphating Solution, to affect the phosphatization effect;

E) hot water wash: be preheating before the phosphatization;

F) phosphatization is processed: will drop into through the blank of overpickling and washing in the phosphoric acid solution of 9g/L zinc oxide and 23mg/L phosphatization and process, and the total acidity 16-20 point of solution, free acidity is the 2.5-4.5 point, temperature is 85-90 ℃, processing time 30-40min;

G) air-cooled;

H) saponification: rise air-cooledly with after the saponification liquor melting blank being immersed in the saponification liquor post-tensioning, and then immerse pull-up, so repeatedly air-cooled again after 3-4 time.

Beneficial effect: the present invention is by pushing metal under room temperature state, and metal grain is tiny after the extruding, and grain size number reaches more than 6 grades, and production efficiency is greatly improved stable and reliable product quality simultaneously.

The specific embodiment

The invention will be further described below in conjunction with embodiment.

Invent described process route: bar wire drawing → annealing → peeling film → surface lubrication → just squeeze → cold-heading molding,

The production efficiency of this mode of production is greatly improved, per tour can be produced about 30000 of blanks, equipment, frock investment lower (only needing 30WRMB of cold headers, mould quadruplet 2WRMB and auxiliary facility that some are auxiliary to amount to 32WRMB), and the distortion of metal is even in the process of continuous cold heading, metallic fiber is complete, greatly improve the intensity index of technology, guaranteed output and quality.

The bar wire drawing

Annealing: adopt pit type annealing furnace to vacuumize and inflated with nitrogen protection annealing, the decarburization of annealing rear oxidation is monolateral≤and 0.1 millimeter, material hardness HB113-120 after the annealing;

Require: 1, firing rate＜150 ℃/h, cooling rate＜50 ℃/h;

2, forvacuum exhausts at every turn and is filled with nitrogen, its pressure 〉=0.01Mpa;

3, the annealing metallographic structure is the F+P ball, and rank is the 4-6 level

Peeling film: remove the oxide skin that the bar surface produces in the step b annealing process;

Surface lubrication:

A) electrochemical deoiling: blank is dropped into the sodium silicate solution of NaOH, 60～80g/L sodium carbonate, 25～80g/L sodium phosphate and the 10～15g/L of 60～100g/L, treatment temperature 〉=85 ℃, 15～25 minutes processing times;

B) mobile clear water is washed;

C) pickling: blank is dropped into pickling in the sodium chloride solution of the sulfuric acid of 120-180g/L and 8-10g/L, pickling temperature is 65-75 ℃, and pickling time is 5-10 minute;

D) clear water that flows is washed: be in order to prevent that the pickle that is adsorbed on blank surface from bringing in the lower road Phosphating Solution, to affect the phosphatization effect;

E) hot water wash: be preheating before the phosphatization;

F) phosphatization is processed: will drop into through the blank of overpickling and washing in the phosphoric acid solution of 9g/L zinc oxide and 23mg/L phosphatization and process, and the total acidity 16-20 point of solution, free acidity is the 2.5-4.5 point, temperature is 85-90 ℃, processing time 30-40min;

G) air-cooled;

H) saponification: rise air-cooledly with after the saponification liquor melting blank being immersed in the saponification liquor post-tensioning, and then immerse pull-up, so repeatedly air-cooled again after 3-4 time.

Just crowded: adopt the hydraulic press of 2000KN to push, extruding force P=60T, bar section beats 0.05.

Cold-heading molding: adopt the cold headers of 500KN to carry out cold-heading, in the taper hole error 0.03, surface roughness 1.6, product axiality 0.1, cold-heading speed 〉=60/min.Change has occured in the metal grain after the cold-heading after testing, makes originally to be bordering on spherical crystal grain owing to distortion is elongated, and is ordered arrangement.Resistance of deformation has been improved to being order state in the crystal grain position, also makes Mechanical Property Anisotropy simultaneously.

Facts have proved the technical characteristics of the valve seating after extruding:

1, grain size is better than 6 grades

2, mechanical property: σ b 〉=1300MPa σ s 〉=900MPa

3, mechanical endurance: 〉=5,000 ten thousand times

In sum: through valve seating quality, the dependable performance that cold forging is produced, production efficiency first mate improves, and cost obviously descends, and can satisfy client's demand.

Claims (3)

1. valve seating cold-heading manufacturing process, it is characterized in that: described cold heading technique may further comprise the steps:

A) bar wire drawing;

B) annealing: adopt pit type annealing furnace to vacuumize and inflated with nitrogen protection annealing, the monolateral degree of depth of annealing rear oxidation decarburization is less than or equal to 0.1 millimeter, and material hardness is HB113-120 after the annealing;

C) peeling film: remove the oxide skin that the bar surface produces in the step b annealing process;

D) surface lubrication: the blank among the step c is carried out oil removing, pickling, washing, phosphatization processing, air-cooled and saponification processing;

E) just crowded: adopt the hydraulic press of 2000KN to push, extruding force is 60T, in the bar section runout error 0.05;

F) cold-heading molding: adopt the cold headers of 500KN to carry out cold-heading, in the taper hole error 0.03, in the surface roughness 1.6,0.1 millimeter of product axiality, cold-heading speed 〉=60/minute.

2. valve seating cold-heading manufacturing process according to claim 1, it is characterized in that: the described annealing heating rate of step b is less than 150 ℃/h, and cooling rate is less than 50 ℃/h; Forvacuum exhausts at every turn and is filled with nitrogen, and its pressure is more than or equal to 0.01MPa; The annealing metallographic structure is the F+P ball, and rank is the 4-6 level.

3. valve seating cold-heading manufacturing process according to claim 1, it is characterized in that: the described surface lubrication of steps d may further comprise the steps:

A) electrochemical deoiling: blank is dropped into the sodium silicate solution of NaOH, 60～80g/L sodium carbonate, 25～80g/L sodium phosphate and the 10～15g/L of 60～100g/L, treatment temperature 〉=85 ℃, 15～25 minutes processing times;

B) mobile clear water is washed;

C) pickling: blank is dropped into pickling in the sodium chloride solution of the sulfuric acid of 120-180g/L and 8-10g/L, pickling temperature is 65-75 ℃, and pickling time is 5-10 minute;

D) clear water that flows is washed: be in order to prevent that the pickle that is adsorbed on blank surface from bringing in the lower road Phosphating Solution, to affect the phosphatization effect;

E) hot water wash: be preheating before the phosphatization;

F) phosphatization is processed: will drop into through the blank of overpickling and washing in the phosphoric acid solution of 9g/L zinc oxide and 23mg/L phosphatization and process, and the total acidity 16-20 point of solution, free acidity is the 2.5-4.5 point, temperature is 85-90 ℃, processing time 30-40min;

G) air-cooled;

H) saponification: rise air-cooledly with after the saponification liquor melting blank being immersed in the saponification liquor post-tensioning, and then immerse pull-up, so repeatedly air-cooled again after 3-4 time.