Preparation method of gradient coating for surface strengthening of blanking die

Abstract

The invention discloses a preparation method of gradient cladding for blanking die surface reinforcing. The preparation method comprises the following steps that a die is preheated, cleared and machined; TRD salt bath salt preparation is conducted, specifically, a salt bath formula comprises, by mass, 70-75% of borax anhydrous, 8-12% of a chrome supplying agent, 4-6% of a niobium supplying agent,3-6% of a reducing agent and 8-10% of an activating agent; salt bath chrome and niobium co-soaking treatment is conducted, specifically, the die is soaked in a molten salt bath, the temperature of thefirst stage is 880-910 DEG C, and the heat-preservation time is 2-3.5 h; the temperature of the second stage is 930-940 DEG C, and the heat-preservation time is 2-3 h; the temperature of the third stage is 980-1040 DEG C, and the heat-preservation time is 3-4 h; and the die is taken out and then tempered after being subjected to oil quenching. According to the preparation method of the gradient cladding for blanking die surface reinforcing, the phenomenon that stress transition of the cladding is uneven is avoided, the service performance of the die is improved, and the service life of the die is prolonged.

Description

technical field

[0001] The invention relates to the technical field of metal materials, in particular to a preparation method of a gradient coating used for surface strengthening of a blanking die. Background technique

[0002] With the continuous development and use of fine blanking technology, especially the stamping of thick steel plates has attracted widespread attention due to its high productivity, superior stamping quality and rich economic benefits. It provides semi-refined blanks for cutting, It has many comprehensive benefits such as saving processing hours and energy consumption, reducing costs, and improving product quality. Compared with thin plate punching, thick plate punching requires greater punching force, and surface wear and heat generation are also more serious. For some molds with sharp corners, lugs or folded intersections, the contact stress during punching is much greater than The average stress, even exceeding the allowable compressive stress of th...

Examples

preparation example Construction

[0035] refer to figure 1 and figure 2 , a method for preparing a gradient coating for surface strengthening of a blanking die, comprising the following steps:

[0036] Step S10, preheating, cleaning and machining the mold;

[0037] Step S20, carry out TRD salt bath salt preparation: the formula of salt bath is: anhydrous borax: 70-75%, chromium donor: 8-12%, niobium donor: 4-6%, reducing agent: 3- 6%, activator: 8-10%, according to the above ratio, first heat the crucible to 820-850°C, gradually add borax until all borax is melted, then add metal donor and activator and stir until they are all melted, finally, Add the reducing agent (in a small amount sequentially) until it melts to form a salt bath, and keep it warm for 1-2 hours;

[0038] Step S30, performing salt bath chromium-niobium co-infiltration treatment: immerse the mold in a molten salt bath, the first stage temperature is 880-910°C, and the holding time is 2-3.5h; the second stage temperature is 930-940°C, hold...

Embodiment 1

[0050] (1) According to the TRD salt bath formula, weigh the corresponding anhydrous borax: 71%, chromium trioxide: 10%, niobium pentoxide: 5%, boron carbide: 4%, sodium fluoride : 10%.

[0051] (2) According to the above ratio, heat and dry the borax in the well-type tempering furnace at 200°C for 1 hour, take it out and mix it with the metal donor powder evenly, then add it to the crucible in turn, and heat up step by step according to the program of the resistance furnace control cabinet. Keep warm at 820°C, after all the salt is melted, slowly add a small amount of B 4 Add C powder and NaF and stir until they all melt to form a salt bath, and keep warm for 1h.

[0052] (3) After grinding and polishing the surface of the Cr12MoV steel workpiece, place it in 5wt% hydrochloric acid for 1min to remove rust, then remove the acid solution with alcohol, then passivate the surface with 5wt% nitric acid solution for 30s, and dry it.

[0053] (4) Immerse the treated workpiece in a...

Embodiment 2

[0062] (1) According to the TRD salt bath formula, weigh the corresponding anhydrous borax: 72%, chromium trioxide: 8%, niobium pentoxide: 4%, Al powder: 6%, sodium fluoride : 8%, rare earth silicon magnesium 2%.

[0063] (2) According to the above ratio, heat and dry the borax in the well-type tempering furnace at 200°C for 1 hour, take it out and mix it with the metal donor powder evenly, then add it to the crucible in turn, and heat up step by step according to the program of the resistance furnace control cabinet. Keep warm at 820°C. After the salt is completely melted, slowly add a small amount of Al powder, sodium fluoride and rare earth in sequence, and stir while adding until all the salt is melted to form a salt bath, and keep warm for 1 hour.

[0064] (3) After grinding and polishing the surface of the Cr12MoV steel workpiece, place it in 5wt% hydrochloric acid for 1min to remove rust, then use alcohol to remove the acid solution, then treat the surface with 5wt% nit...

technical field

[0001] The invention relates to the technical field of metal materials, in particular to a preparation method of a gradient coating used for surface strengthening of a blanking die. Background technique

[0002] With the continuous development and use of fine blanking technology, especially the stamping of thick steel plates has attracted widespread attention due to its high productivity, superior stamping quality and rich economic benefits. It provides semi-refined blanks for cutting, It has many comprehensive benefits such as saving processing hours and energy consumption, reducing costs, and improving product quality. Compared with thin plate punching, thick plate punching requires greater punching force, and surface wear and heat generation are also more serious. For some molds with sharp corners, lugs or folded intersections, the contact stress during punching is much greater than The average stress, even exceeding the allowable compressive stress of th...

Examples

preparation example Construction

[0035] refer to figure 1 and figure 2 , a method for preparing a gradient coating for surface strengthening of a blanking die, comprising the following steps:

[0036] Step S10, preheating, cleaning and machining the mold;

[0037] Step S20, carry out TRD salt bath salt preparation: the formula of salt bath is: anhydrous borax: 70-75%, chromium donor: 8-12%, niobium donor: 4-6%, reducing agent: 3- 6%, activator: 8-10%, according to the above ratio, first heat the crucible to 820-850°C, gradually add borax until all borax is melted, then add metal donor and activator and stir until they are all melted, finally, Add the reducing agent (in a small amount sequentially) until it melts to form a salt bath, and keep it warm for 1-2 hours;

[0038] Step S30, performing salt bath chromium-niobium co-infiltration treatment: immerse the mold in a molten salt bath, the first stage temperature is 880-910°C, and the holding time is 2-3.5h; the second stage temperature is 930-940°C, hold...

Embodiment 1

[0050] (1) According to the TRD salt bath formula, weigh the corresponding anhydrous borax: 71%, chromium trioxide: 10%, niobium pentoxide: 5%, boron carbide: 4%, sodium fluoride : 10%.

[0051] (2) According to the above ratio, heat and dry the borax in the well-type tempering furnace at 200°C for 1 hour, take it out and mix it with the metal donor powder evenly, then add it to the crucible in turn, and heat up step by step according to the program of the resistance furnace control cabinet. Keep warm at 820°C, after all the salt is melted, slowly add a small amount of B 4 Add C powder and NaF and stir until they all melt to form a salt bath, and keep warm for 1h.

[0052] (3) After grinding and polishing the surface of the Cr12MoV steel workpiece, place it in 5wt% hydrochloric acid for 1min to remove rust, then remove the acid solution with alcohol, then passivate the surface with 5wt% nitric acid solution for 30s, and dry it.

[0053] (4) Immerse the treated workpiece in a...

Embodiment 2

[0062] (1) According to the TRD salt bath formula, weigh the corresponding anhydrous borax: 72%, chromium trioxide: 8%, niobium pentoxide: 4%, Al powder: 6%, sodium fluoride : 8%, rare earth silicon magnesium 2%.

[0063] (2) According to the above ratio, heat and dry the borax in the well-type tempering furnace at 200°C for 1 hour, take it out and mix it with the metal donor powder evenly, then add it to the crucible in turn, and heat up step by step according to the program of the resistance furnace control cabinet. Keep warm at 820°C. After the salt is completely melted, slowly add a small amount of Al powder, sodium fluoride and rare earth in sequence, and stir while adding until all the salt is melted to form a salt bath, and keep warm for 1 hour.

[0064] (3) After grinding and polishing the surface of the Cr12MoV steel workpiece, place it in 5wt% hydrochloric acid for 1min to remove rust, then use alcohol to remove the acid solution, then treat the surface with 5wt% nit...

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