CN104209639A - Mold cutting edge repair welding process - Google Patents

Abstract

The invention relates to a mold cutting edge repair welding process. The mold cutting edge repair welding process comprises the following steps: S1, making preparations before welding; S11, drying a welding rod; S12, opening a break; S13, cleaning; S2, preheating: putting a mold into an electric heating furnace, uniformly heating to 250-450 DEG C, and taking the mold out; S3, welding: fixing a mold parent material onto a workbench, and welding by adopting low current gas arc and vertical short arc operation, reverse welding and uniform filling, and jointing during layered staggered welding; S4, heating and preserving heat: putting the welded mold back into the electric heating furnace for heating till the temperature is up to 150-300 DEG C, preserving heat for 25-35 minutes, and the performing furnace cooling; S5, assembling after welding: trimming a welding area, forming a gap, assembling the mold on a machine tool, performing trial production, and detecting a product. The mold cutting edge repair welding process has the advantages of simple machining process, short period, low cost and long service life after repair welding.

Description

Die point repair welding

Technical field

The present invention relates to the better Cr of quenching degree ₁₂the repair welding of MoV mould steel, particularly die point repair welding.

Background technology

Along with the fast development of auto industry, the processing and manufacturing of various diel and use more and more general, my company as a vapour Toyota, FAW-Volkswagen rush the supporting producer of weldment, within 1 year, have the frequent use technology maintenance of thousands of mold.Because mould use amount is very large, die point often produce gnaw bad, tipping, the phenomenons such as Local Cracking, although adopt block insert type to carry out assembled at Design of Dies with trying one's best when manufacturing for reducing maintenance cost, but because the size of indivedual insert is larger, structure is more complicated again, especially Trimming Die, its tough mouth-shaped very irregular, and be subject to the restriction of product shape and size, if after damaging, processing need through blanking again for it, forging, machined, heat treatment, electric spark, the series of process processes such as fine grinding, its complex technical process, process-cycle is long, manufacturing cost is high, affect larger on production schedule arrangement and Panel management management.

At present, criticize production mould and generally adopt the better Cr of quenching degree ₁₂moV mould steel, has high hardness, wearability and compression strength after heat treatment, be commonly used to manufacture the blanking die that cross section is larger, complex-shaped, stand greater impact.Cr ₁₂carbon equivalent ce=3.8% ~ 4.4% of MoV steel, is typical difficult welding material, often occurs welding cold cracking and reheat crack(ing), and its repair welding is always a difficult problem of die industry.

Summary of the invention

The object of the invention is to the shortcoming overcoming prior art, provide that a kind of processing technology is simple, the cycle is short, cost is low and the die point repair welding of long service life after repair welding.

Object of the present invention is achieved through the following technical solutions: die point repair welding comprises the following steps:

S1, welds prepares:

S11, dry welding rod: be placed in electric furnace by the welding rod matched with die point material, after oven dry, take out for subsequent use;

S12, open cut: determine mould damage position, by clean for the polishing of defect place;

S13, clean: to remove die point surface, wipe oil;

S2, preheating: be put into by mould in electric furnace, be uniformly heated to 250 DEG C ~ 450 DEG C, takes out;

S3, welding: mold base material is fixed on the table, the method for the contact adopting low current gas loop, vertically short arc operation, the even filling chock of the welding that falls back, layering to interlock when welding is welded;

S4, intensification being incubated: put back in electric furnace by the mould after welding at once and heat, until temperature reaches 150 DEG C ~ 300 DEG C, insulation, cools with stove after 25min ~ 35min;

S5, postwelding assemble: welding region is carried out reconditioning process, joins gap, by die assembly on lathe, manufacture experimently, and detect product.

Described step S3 adopts TIG pulse machine to weld, and its welding current is 70 A ~ 90A.

The present invention has the following advantages:

1, the welding procedure that this technique mainly adopts low current gas loop, vertical short arc operation, the even filling chock of the welding that falls back, layering interlocks welding, welding procedure is simple.

2, adopt repair welding to carry out repair compared to machining again, the man-hour of its repair welding is 1/20 of machining, significantly shortens man-hour, and reduces the manufacturing cost of workpiece.

3, workpiece after repair welding no significant defect from the appearance, do fracture analysis and do not find pore, be mingled with, the defects such as incomplete fusion, overlay cladding and mother metal matrix fuse well, interpenetrate, bond strength is higher, the microscopic structure of surfacing layer metal is the carbide of martensite+bainite+retained austenite+Dispersed precipitate, this tissue has good anti-wear performance, reason is that chromium and iron can form solid solution, multiple carbide is formed with carbon, this element significantly improves the intensity of overlay cladding, hardness and wearability, and V, the refining effect of the elements such as Mo makes overlay cladding crystal grain thinner, thus ensure that toughness and the intensity of workpiece, vanadium is more much bigger than the affinity of iron to carbon to the affinity of carbon, anti-blocking and iron generate cementite, the vanadium carbide disperse generated is on martensitic matrix, make cutting edge have certain wearability and be but unlikely crack resistance variation, in addition the existence of a small amount of retained austenite, improve the crack resistance of surfacing layer metal, transition zone tissue is bainite+ferrite, though its hardness decreases, but hardness gradient distribution rationally, improve the anti-cracking performance of surfacing layer metal, therefore, workpiece after repair welding has the feature of long service life.

Detailed description of the invention

Below in conjunction with embodiment, the present invention will be further described, but protection scope of the present invention is not limited to the following stated.

[embodiment 1]:

Die point repair welding comprises the following steps:

S1, welds prepares:

S11, dry welding rod: be placed in electric furnace by the welding rod matched with die point material, after oven dry, take out for subsequent use;

S12, open cut: determine mould damage position, by clean for the polishing of defect place;

S13, clean: to remove die point surface, wipe oil;

S2, preheating: be put into by mould in electric furnace, be uniformly heated to 250 DEG C ~ 450 DEG C, takes out;

S3, welding: mold base material is fixed on the table, the method for the contact adopting low current gas loop, vertically short arc operation, the even filling chock of the welding that falls back, layering to interlock when welding is welded;

S4, intensification being incubated: put back in electric furnace by the mould after welding at once and heat, until temperature reaches 150 DEG C ~ 300 DEG C, insulation, cools with stove after 25min ~ 35min;

S5, postwelding assemble: welding region is carried out reconditioning process, joins gap, by die assembly on lathe, manufacture experimently, and detect product.

Described step S3 adopts TIG pulse machine to weld, and its welding current is 70 A ~ 90A.

[embodiment 2]:

Die point repair welding comprises the following steps:

S1, welds prepares:

S11, dry welding rod: be placed in electric furnace by the welding rod matched with die point material, after oven dry, take out for subsequent use;

S12, open cut: determine mould damage position, by clean for the polishing of defect place;

S13, clean: to remove die point surface, wipe oil;

S2, preheating: be put into by mould in electric furnace, be uniformly heated to 250 DEG C ~ 450 DEG C, takes out;

S3, welding: mold base material is fixed on the table, the method for the contact adopting low current gas loop, vertically short arc operation, the even filling chock of the welding that falls back, layering to interlock when welding is welded;

S4, intensification being incubated: put back in electric furnace by the mould after welding at once and heat, until temperature reaches 150 DEG C ~ 300 DEG C, insulation, cools with stove after 25min ~ 35min;

S5, postwelding assemble: welding region is carried out reconditioning process, joins gap, by die assembly on lathe, manufacture experimently, and detect product.

Described step S3 adopts TIG pulse machine to weld, and its welding current is 70 A ~ 90A.

[embodiment 3]:

Die point repair welding comprises the following steps:

S1, welds prepares:

S11, dry welding rod: be placed in electric furnace by the welding rod matched with die point material, after oven dry, take out for subsequent use;

S12, open cut: determine mould damage position, by clean for the polishing of defect place;

S13, clean: to remove die point surface, wipe oil;

S2, preheating: be put into by mould in electric furnace, be uniformly heated to 250 DEG C ~ 450 DEG C, takes out;

S3, welding: mold base material is fixed on the table, the method for the contact adopting low current gas loop, vertically short arc operation, the even filling chock of the welding that falls back, layering to interlock when welding is welded;

S4, intensification being incubated: put back in electric furnace by the mould after welding at once and heat, until temperature reaches 150 DEG C ~ 300 DEG C, insulation, cools with stove after 25min ~ 35min;

S5, postwelding assemble: welding region is carried out reconditioning process, joins gap, by die assembly on lathe, manufacture experimently, and detect product.

Described step S3 adopts TIG pulse machine to weld, and its welding current is 70 A ~ 90A.

Claims (2)

1. die point repair welding, is characterized in that: it comprises the following steps:

S1, welds prepares:

S11, dry welding rod: be placed in electric furnace by the welding rod matched with die point material, after oven dry, take out for subsequent use;

S12, open cut: determine mould damage position, by clean for the polishing of defect place;

S13, clean: to remove die point surface, wipe oil;

S2, preheating: be put into by mould in electric furnace, be uniformly heated to 250 DEG C ~ 450 DEG C, takes out;

S3, welding: mold base material is fixed on the table, the method for the contact adopting low current gas loop, vertically short arc operation, the even filling chock of the welding that falls back, layering to interlock when welding is welded;

S4, intensification being incubated: put back in electric furnace by the mould after welding at once and heat, until temperature reaches 150 DEG C ~ 300 DEG C, insulation, cools with stove after 25min ~ 35min;

S5, postwelding assemble: welding region is carried out reconditioning process, joins gap, by die assembly on lathe, manufacture experimently, and detect product.

2. die point repair welding according to claim 1, is characterized in that: described step S3 adopts TIG pulse machine to weld, and its welding current is 70 A ~ 90A.