CN103789663A - Preparation method of cold work die steel used for stamping housings of household electrical appliances - Google Patents

Abstract

The invention discloses a preparation method of cold work die steel used for stamping housings of household electrical appliances. The cold work die steel comprises following components by weight: 0.9-1.1% of C, 0.3-0.5% of Si, 1.3-1.5% of Mn, 4.2-4.6% of Cr, 0.6-0.8% of W, 0.15-0.25% of V, 1.5-1.7% of Ni and 0.1-0.3% of Ti, with the balance being Fe. The preparation method comprises 1) a step of smelting by adoption of an induction furnace or an electric-arc furnace; 2) a step of electroslag remelting; 3) a step of forging; 4) a step of annealing, wherein the material after being forged is annealed at 800-810 DEG C for 6-10 h and is then cooled inside the furnace; and 5) a step of thermal treatment, wherein the material is heated to 935-945 DEG C to perform austenization, quenched with oil and subjected to a two-step tempering with the tempering temperature being 220-240 DEG C and the tempering time for each tempering step is 2.5-3.5 h.

Description

The preparation method of cold-work die steel for a kind of appliance shell punching press

Technical field

The present invention relates to technical field of ferrous metallurgy, relate in particular to the preparation method of a kind of appliance shell punching press cold-work die steel.

Background technology

Mould is the fundamental technology equipment of the Industrial products such as machinery, electronics, automobile, communication, household electrical appliances.As basic industry, the quality of mould, precision, life-span play very vital role to other industrial expansions, and the development of national economy is played to apodeictic keying action.Cold-work die steel is mainly used in punching press, blanking, moulding, bending, cold extrusion, cold drawn, powder metallurgy die etc., requires to have high rigidity, high-wearing feature and enough toughness.Generally be divided into the universal and large class of special type two.For a long time, China extensively adopts CrWMn, the Cr12 shaped steel main separation material as cold-work die.Because the former easily forms carbide network, the latter easily forms banded carbide, and the macrosegregation of carbide reduces the obdurability of mould, causes mould tipping, ruptures or subsides.For solving the early failure problem of mould, widen the demand of mould industry to steel, the new steel grades such as the rapid steel that domesticly in succession succeed in developing a collection of high strength, high tenacity, resistance to wear, red hardness is good, matrix steel, thermal treatment stentor steel, Steel Bond Hard Alloy.In order to adapt to industrial expansion demand, the researchist of China is in the exploitation of die steel new steel grade, be mainly for when front mold in use existing work-ing life problem, ftracture, subside etc. due to failure mode, adjust existing mold material interalloy composition, guaranteeing under the prerequisite of the existing performance of material, adjust material interalloy constituent content, reduce material produce cost, or on the moulding stock basis wide in current application, performance is high, improve alloying element proportioning, make mechanical property and the use properties of material tool get Geng Gao.The Working environment of die steel and working conditions, require material to have high heat resistance and hardening capacity, so in these two alloying thinkings, research the latter's is in the majority.Thereby the alloying thinking of mainly taking at home is at present mainly in material, to add alloying elements to make material have the obdurability that once improves material with secondary hardening effect, simultaneously, except Cr, Mn, add again the elements such as Mo, W, V and Ni, assurance material structure is tiny, and age hardening effect obviously has good obdurability.If DS steel is that in adopting, carbon adds Ni, replace part W with Mo, a kind of high tenacity shockproof die steel of polynary a small amount of alloying alternatives formulation, has good manufacturability and mechanical property.

But emerging die steel or performance are not as traditional moulds steel, or cost is too high, general user is difficult to accept.Particularly household electrical appliances manufacturing, due to intensified competition, requires to reduce manufacturing cost, and therefore, the mould that cost is higher can not adapt to this development trend.

Summary of the invention

The object of the invention is to propose the preparation method of a kind of appliance shell punching press cold-work die steel, this die steel has good obdurability combination, and improve work-ing life than existing CrWMn, Cr12 shaped steel, and preparation cost reduces.

For reaching this object, the present invention by the following technical solutions:

A preparation method for cold-work die steel for appliance shell punching press, described die steel is made up of following component by weight percentage: C:0.9-1.1, Si:0.3-0.5, Mn:1.3-1.5, Cr:4.2-4.6, W:0.6-0.8, V:0.15-0.25, Ni:1.5-1.7, Ti:0.1-0.3, Fe surplus; Described preparation method comprises the steps:

1) adopt induction or arc melting: by above-mentioned alloying element proportioning, batching is put into electric furnace, carry out melting;

2) esr: the ESR ingot that melting pouring is gone out is put in esr device, carries out esr;

3) forge: by above-mentioned Heating Steel Ingots to 1170-1190 ℃ of temperature range; Initial forging temperature: 1110-1130 ℃, final forging temperature >=880 ℃, slow cooling after forging;

4) annealing: material, after forging, is annealed at 800-810 ℃, annealing 6-10 hour, subsequently furnace cooling;

5) thermal treatment: be heated to 935-945 ℃ and carry out austenitizing, adopt oil quenching; Carry out subsequently double tempering, tempering temperature is 220-240 ℃, and each tempering time is 2.5-3.5h.

The theoretical foundation of its Composition Design of cold-work die steel of the present invention is as described below:

In alloying element in steel, Cr guarantees that steel has good hardening capacity.The content of Cr is unsuitable too high, otherwise the easy webbed carbide of shape, affects the performance of steel.Ni simultaneously can keep good plasticity and toughness in the intensity that improves steel, but Ni belongs to scarce resource, adds appropriate Ni in steel of the present invention, makes that under prerequisite that the obdurability of steel is good, cost of alloy can be too not high.W and V form the Second Phase Precipitation thing of disperse in steel, improve the obdurability of material.Si Main Function is the temper resistance that improves steel.Mn dissolves in and in matrix, plays solution strengthening effect.Ti plays the effect of crystal grain thinning, thereby further improves the obdurability of die steel.

The present invention has following beneficial effect:

It is good that the present invention has developed hardening capacity, and quenching temperature is lower, and heat treatment deformation is little, and cost of alloy is low, has the cooperation of good intensity and toughness, is applicable to appliance shell press tool steel.Its performance is: quenching hardness: 66-67HRC, tempered-hardness: 62-63HRC, room temperature impact toughness value: 180-190J, room temperature bending strength: 3100-3150MPa, maximum deflection power: 4850KN, amount of deflection: 13.1mm.

Embodiment

Embodiment mono-

A preparation method for cold-work die steel for appliance shell punching press, described die steel is made up of following component by weight percentage: C:0.9, Si:0.5, Mn:1.3, Cr:4.6, W:0.6, V:0.25, Ni:1.5, Ti:0.3, Fe surplus; Described preparation method comprises the steps:

1) adopt induction or arc melting: by above-mentioned alloying element proportioning, batching is put into electric furnace, carry out melting.

2) esr: the ESR ingot that melting pouring is gone out is put in esr device, carries out esr;

3) forge: in above-mentioned Heating Steel Ingots to 1170 ℃ temperature range; Initial forging temperature: 1130 ℃, final forging temperature >=880 ℃, slow cooling after forging;

4) annealing: material, after forging, is annealed at 800 ℃, anneals 10 hours, furnace cooling subsequently;

5) thermal treatment: be heated to 935 ℃ and carry out austenitizing, adopt oil quenching; Carry out subsequently double tempering, tempering temperature is 240 ℃, and each tempering time is 2.5h.

Embodiment bis-

A preparation method for cold-work die steel for appliance shell punching press, described die steel is made up of following component by weight percentage: C:1.1, Si:0.3, Mn:1.5, Cr:4.2, W:0.8, V:0.15, Ni:1.7, Ti:0.1, Fe surplus; Described preparation method comprises the steps:

1) adopt induction or arc melting: by above-mentioned alloying element proportioning, batching is put into electric furnace, carry out melting.

2) esr: the ESR ingot that melting pouring is gone out is put in esr device, carries out esr;

3) forge: in above-mentioned Heating Steel Ingots to 1190 ℃ temperature range; Initial forging temperature: 1110 ℃, final forging temperature >=880 ℃, slow cooling after forging;

4) annealing: material, after forging, is annealed at 810 ℃, anneals 6 hours, furnace cooling subsequently;

5) thermal treatment: be heated to 945 ℃ and carry out austenitizing, adopt oil quenching; Carry out subsequently double tempering, tempering temperature is 220 ℃, and each tempering time is 3.5h.

Embodiment tri-

A preparation method for cold-work die steel for appliance shell punching press, described die steel is made up of following component by weight percentage: C:1.0, Si:0.4, Mn:1.4, Cr:4.4, W:0.7, V:0.20, Ni:1.6, Ti:0.2, Fe surplus; Described preparation method comprises the steps:

1) adopt induction or arc melting: by above-mentioned alloying element proportioning, batching is put into electric furnace, carry out melting.

2) esr: the ESR ingot that melting pouring is gone out is put in esr device, carries out esr;

3) forge: in above-mentioned Heating Steel Ingots to 1180 ℃ temperature range; Initial forging temperature: 1120 ℃, final forging temperature >=880 ℃, slow cooling after forging;

4) annealing: material, after forging, is annealed at 805 ℃, anneals 8 hours, furnace cooling subsequently;

5) thermal treatment: be heated to 940 ℃ and carry out austenitizing, adopt oil quenching; Carry out subsequently double tempering, tempering temperature is 230 ℃, and each tempering time is 3h.

Claims (1)

1. the preparation method of an appliance shell punching press use cold-work die steel, it is characterized in that, described die steel is made up of following component by weight percentage: C:0.9-1.1, Si:0.3-0.5, Mn:1.3-1.5, Cr:4.2-4.6, W:0.6-0.8, V:0.15-0.25, Ni:1.5-1.7, Ti:0.1-0.3, Fe surplus; Described preparation method comprises the steps:

1) adopt induction or arc melting: by above-mentioned alloying element proportioning, batching is put into electric furnace, carry out melting;

2) esr: the ESR ingot that melting pouring is gone out is put in esr device, carries out esr;

3) forge: by above-mentioned Heating Steel Ingots to 1170-1190 ℃ of temperature range; Initial forging temperature: 1110-1130 ℃, final forging temperature >=880 ℃, slow cooling after forging;

4) annealing: material, after forging, is annealed at 800-810 ℃, annealing 6-10 hour, subsequently furnace cooling;

5) thermal treatment: be heated to 935-945 ℃ and carry out austenitizing, adopt oil quenching; Carry out subsequently double tempering, tempering temperature is 220-240 ℃, and each tempering time is 2.5-3.5h.