CN103290354B

CN103290354B - Nitrocarburizing optimizing process of Cr12MoV steel

Info

Publication number: CN103290354B
Application number: CN201210044539.8A
Authority: CN
Inventors: 陶立民; 孙文娟; 曹韵牧; 马梅艳; 郑海钧
Original assignee: Shanghai Huizhong Automotive Manufacturing Co Ltd
Current assignee: Shanghai Huizhong Automotive Manufacturing Co Ltd
Priority date: 2012-02-24
Filing date: 2012-02-24
Publication date: 2015-07-15
Anticipated expiration: 2032-02-24
Also published as: CN103290354A

Abstract

The invention aims to provide a nitrocarburizing optimizing process of Cr12MoV steel, and is used for enhancing the abrasion resistance of a material. The process is characterized by comprising the following process parameters: the process temperature ranges from 510 to 520 DEG C; the volume ratio of NH3 to CO2 ranges 8:(1-12):1; the NH3 flow ranges from 40 to 60 mL/min (milliliter per minute); the furnace pressure ranges from 500 to 700Pa. In addition, the plasma nitrocarburizing is carried out by adding rare earth La; the sputtering quantity of the rare earth La is regulated and controlled via the furnace pressure, so that the concentration of rare earth La ions in the atmosphere of a furnace is regulated quantificationally. Thus, the rare earth La before and after being used is weighed quantificationally and accurately, i.e., the concentration of the rare earth La in the furnace forms the positive relationship with the mass loss of the rare earth. Therefore, the quantitative nitrocarburizing catalysis of the rare earth La is realized.

Description

The carbonitriding Optimization Technology of Cr12MoV steel

Technical field

The present invention relates to ionitrocarburizing method, particularly relate to Cr12MoV steel at plasma nitrogen carbon co-permeation method.

Background technology

Cr12MoV steel in the market seldom adopts rare earth quantitatively to urge and infilters row carbonitriding (NH ₃+ CO ₂), the present invention relates to and in the optimization plasma body nitrogen-carbon cocementing process parameter of probing into out, use rare earth La quantitatively to urge ooze.In automobile industry, stamping parts accounts for automobile component the ratio exceeding half.The failure mode of mould and maintenance situation are one of most important reasons affecting conforming product rate and production cost.Wherein, cold-punching mould is mainly used in and makes metal blank produce viscous deformation or separation and shape required product aspect, all higher to index requests such as the hardness of moulding stock, toughness, wear resistance and anti-fatigue performances.High duty alloy tool steel generally selected by mould for the production of workpiece more in enormous quantities, such as Cr12MoV, DC53 steel etc.The principal element affecting the cold-punching mold life-span has: (1) mould structure design; (2) mfg. moulding die selected materials and thermal treatment process thereof; (3) surface strengthening and maintaining thereof.In above three factors, any one goes wrong, and all may make mould premature failure, cause die size precision and poor surface quality, more serious or mould is scrapped in advance.

For the online cold-punching mold used, premature failure and normal inefficacy often can be run into.And the main failure forms of cold-punching mould routine is wearing and tearing, because metal blank exists strong friction with punch and matrix surface in separation, shaping, flow process, thus make poor surface quality, even die size precision reduces.Therefore, need through repeatedly reconditioning, comprise light maintenance and in repair, even twice overhaul, to extend its work-ing life.For the cold-punching mold in using, improving the most Practical and efficient method of its wear resisting property is carry out surface reconditioning to it, strengthens maintenance.Outer hard interior tough characteristic is kept to make mould.One of recovery technique major technique of present actual mould is exactly ionitrocarburizing, and because this kind of method has nitriding speed soon, workpiece deformation is little, saves the advantages such as the energy, so adopt ionitrocarburizing method can well solve mould repair problem.And in actual application, as shaping cold-punching mold, the infiltration layer of ionitrocarburizing has larger thickness, and not ionitriding only has the high hardness in surface, and therefore the wear resisting property of ionitrocarburizing to material has better effect.In addition, rare earth element surface treatment urge ooze in studied widely, the distinctive electron structure of rare earth element and atomic size, the rare earth be present in steel has following two features: 1. have stronger chemical affinity; 2. the energy of system can be reduced.Therefore, comprise the atom air mass of nitrogen, carbon by being formed when carbonitriding around rare earth atoms, when oozing altogether, rare earth add the diffusion that can promote C, atom N.And mainly ooze for qualitative the urging of rare earth in existing research, such as patent " rare earth catalytic cementation Ion Sulphur, nitrogen, carbon co-cementation agent and technique " (application number: the research 92114422.9) all seldom relating to quantitative aspect; The earth solution collocation method related in " rare earth, carbon, nitrogen trielement coexudation agent and compound method thereof " (item number: czl05055533) is then because evaporation, saturation ratio and vacuum tightness affect production operation and difficult quantitation.

Summary of the invention

The object of the present invention is to provide the carbonitriding Optimization Technology of Cr12MoV steel, with the wear resisting property of strongthener.

For solving the carbonitriding Optimization Technology of the Cr12MoV steel of described problem, be characterized in that there is processing parameter: technological temperature between 510 DEG C to 520 DEG C, NH ₃: CO ₂(volume percent) between 8: 1 to 12: 1, NH ₃flow is between 40mL/min to 60mL/min, and furnace pressure is between 500Pa to 700Pa.

The carbonitriding Optimization Technology of described Cr12MoV steel, its further feature also adds rare earth La to carry out plasma carbonitriding, the sputtering amount of rare earth La is regulated and controled by the control of furnace pressure, quantitatively to regulate the concentration of rare earth La ion in furnace atmosphere, afterwards accurate quantitative weighing is carried out before use to rare earth La, the weight loss of the concentration of rare earth La in stove and rare earth is proportional, thus realizes quantitatively urging of rare earth La and ooze.

The carbonitriding Optimization Technology of described Cr12MoV steel, its further feature is the weight of described rare earth La is 10.41g.

The carbonitriding Optimization Technology of described Cr12MoV steel, the bulk of its further feature to be described rare earth La be 10 × 10 × 6mm.

Under the quantitative catalytic cementation process condition of rare earth La of recommending, the Thickness Ratio of bright layer increases 5-10 μm when not adding rare earth, total alloying layer thickness increases about 40-60 μm, surface hardness can reach 920HV, frictional wear experiment finds that the abrasion loss of original sample is 0.014-0.016g, in Optimization Technology situation, the abrasion loss of standard test specimen is reduced to 0.009g-0.010g, and add the sample of rare earth, abrasion loss is reduced to 0.008-0.009g further, wear resisting property significantly improves, thus enhances productivity, and reduces production cost.

So the present invention quantitatively urges the research field of infiltration method to have great importance at rare earth.

Accompanying drawing explanation

Fig. 1 is the actual samples abrasion loss of Cr12MoV steel after various different carbonitriding treatment process.

Embodiment

The aftermentioned embodiment comprising two aspects, being the Optimization Technology (optimization of processing parameter) of plasma body carbonitriding on the one hand, is that the rare earth La carried out on the basis of Optimization Technology quantitatively urges infiltration method on the other hand.

1, the process of plasma body nitrogen-carbon cocementing process parameter is as follows, and orthogonal experiment form is as table 1

Table 1 carbonitriding and rare earth catalytic cementation test orthogonal form

The nitrogen-carbon cocementing process parameter that Cr12MoV steel is optimized can have been drawn: NH in 510-520 DEG C of furnace temperature situation by table 1 ₃: CO ₂(volume percent)=8: 1-12: 1, NH ₃flow is 40-60mL/min, and furnace pressure is 500-700Pa.

2, rare earth La quantitatively urges infiltration method as follows:

A. by orthogonal experimental method, probing into out the plasma nitrogen-carbon cocementing process parameter relatively optimized is: the temperature of oozing altogether is 510-520 DEG C, NH ₃flow be 40-60mL/min, NH ₃: CO ₂(volume percent)=8: 1-12: 1, furnace pressure is 500-700Pa;

B. mechanical workout is carried out to rare earth La block, be of a size of 10 × 10 × 6mm, and the weight of the 3 blocks of rare earths added before weighing experiment is 10.41g;

C. on the basis of Cr12MoV optimization confusion technology parameter, add rare earth block and carry out plasma carbonitriding, the quality weighing rare earth La block after experiment is 10.25g;

D., after quantitatively adding rare earth La, microstructure observation and performance test are carried out to Cr12MoV mould bloom.

In table 1, experiment K, L have aforementioned rare earth La quantitatively to urge the processing parameter oozed.

Under the quantitative catalytic cementation process condition of rare earth La of recommending, increase 5-10 μm when the Thickness Ratio of bright layer does not add rare earth, total alloying layer thickness increases about 40-60 μm, and surface hardness can reach 920HV; Frictional wear experiment finds that the abrasion loss of original sample is 0.014-0.016g, in Optimization Technology situation, the abrasion loss of standard test specimen is reduced to 0.009g-0.010g, and add the sample of rare earth, abrasion loss is further reduced to 0.008-0.009g, wear resisting property significantly improves, thus enhances productivity, and reduces production cost.

Advantage and effect

As shown in Figure 1, under the quantitative catalytic cementation process condition of rare earth La of recommending, the Thickness Ratio of bright layer increases 5-10 μm when not adding rare earth, total alloying layer thickness increases about 40-60 μm, surface hardness can reach 920HV, frictional wear experiment finds that the abrasion loss of original sample is 0.014-0.016g, in Optimization Technology situation, the abrasion loss of standard test specimen is reduced to 0.009g-0.010g, and adding the sample of rare earth, abrasion loss is reduced to 0.008-0.009g further, and wear resisting property significantly improves, thus enhance productivity, reduce production cost.

Claims

The carbonitriding Optimization Technology of 1.Cr12MoV steel, is characterized in that, adopts plasma carbonitriding, has processing parameter: technological temperature between 510 DEG C to 520 DEG C, NH ₃: CO ₂(volume percent) between 8:1 to 12:1, NH ₃flow is between 40mL/min to 60mL/min, and furnace pressure is between 500Pa to 700Pa.
2. the carbonitriding Optimization Technology of Cr12MoV steel as claimed in claim 1, it is characterized in that also adding block rare earth La carries out plasma carbonitriding, the sputtering amount of rare earth La is regulated and controled by the control of furnace pressure, quantitatively to regulate the concentration of rare earth La ion in furnace atmosphere, afterwards accurate quantitative weighing is carried out before use to rare earth La, the weight loss of the concentration of rare earth La in stove and rare earth is proportional, thus realizes quantitatively urging of rare earth La and ooze.
3. the carbonitriding Optimization Technology of Cr12MoV steel as claimed in claim 2, is characterized in that the weight of described rare earth La is 10.41g.
4. the carbonitriding Optimization Technology of Cr12MoV steel as claimed in claim 3, is characterized in that described rare earth La is the bulk of 10 × 10 × 6mm.