CN104133083A

CN104133083A - Method for quantitative detection of MC carbide in high-V high-speed steel

Info

Publication number: CN104133083A
Application number: CN201410324903.5A
Authority: CN
Inventors: 孙宗林; 王红; 张巍; 李栋; 张朋
Original assignee: Heye Sci & Tech Co Ltd
Current assignee: Heye Sci & Tech Co Ltd
Priority date: 2014-07-09
Filing date: 2014-07-09
Publication date: 2014-11-05

Abstract

The invention relates to a method for quantitative detection of an MC carbide in a high-V high-speed steel. The steps are as follows: a. sampling: cutting a sample, the length L of which is 10-20mm, from a to-be-detected steel material and sectioning the sample along the center and using a half cylinder as a sample; b. sample processing: polishing the center plane of the sample; c. image acquisition: adopting a back scattering electronic probe in a scanning electron microscope to acquire an image of a place of the center plane, 1/8 diameter or 1/4 diameter from a radial edge of the center plane; d. data statistics: adopting metallographic software to analyze the picture so that an MC carbide particle granularity and area ratio data result is obtained. The method uses combination of the scanning electron microscope and quantitative metallographic software analysis to rapidly and accurately detect the size and quantity of the MC carbide and provides a detection method, which is capable of saving a corrosion processing operation on the sample, for quantitative detection of the MC carbide; and the method is simple and convenient in operation and high in detection precision.

Description

Quantitatively detect the method for high V Primary MC Carbide in High Speed Steels

Technical field

The present invention relates to a kind of quantitative detecting method of carbonide, relate in particular to the detection method of the high V Primary MC Carbide in High Speed Steels of a kind of quantitative detection.

Background technology

Detect at present the method for High-Speed Steel Carbide, according to GB/T9943-2008 < < high speed tool steel > >, the national standards such as the irregularity of eutectic carbides rating method > > of GB/T14979-94 < < steel, all on steel, to cut sample, sample is cleaned, inlay, grind, after using 4% nital deep etch, under metaloscope, detect, contrast with the given grading collection of illustrative plates of standard, judge Carbide Nonuniformity rank and granularity rank.The testing process of whole sample is that artificial observation is evaluated, and has operating personnel's personal error; And in corrosion process, need one or many corrosion could be under metaloscope clear observing, extended detection time.

Chinese invention patent application CN 102486460 A disclose the detection method of Laves phase and Carbide Phases in a kind of high Nb Fe Ni matrix high temperature alloy, after grinding, polishing, polished surface to be exposed on high Nb Fe Ni matrix high temperature alloy sample, then be placed in heat-treatment furnace, at 350 ~ 600 ℃ of furnace temperature standing 10 ~ 200 minutes, air cooling, utilizes the high Nb Fe Ni matrix high temperature alloy sample after metallography microscope sem observation is processed.This method is just observed Carbide Phases and the difference of Laves phase, belongs to the qualitative analysis to carbonide, and in the method, sample has been adopted to thermal treatment.

Chinese invention patent application CN 103308514 A disclose a kind of method that adopts annealed state normal temperature etch testing tool steel carbonide unevenness, adopt mechanical means by annealed state specimen surface sanding and polishing, then in particular etch liquid, polished specimen surface is carried out to 30～60 seconds of corrosion treatment, sample after corrosion is used to metallography microscope Microscopic observation, the result of observing is black ferrite matrix+white carbide particle, wherein, proeutectoid carbide presents ribbon and distributes and net distribution, chain or strip that eutectic carbide presents large bulk distribute.The method is still the qualitative analysis to carbonide, can only observe form and the distribution situation of carbonide, can not quantitatively determine size and the quantity of carbonide, and in the method, sample still adopted to corrosion treatment.

Chinese invention patent application CN 102374990 A disclose a kind of prestress wire wire rod net carbide ranking method, first on wire rod, intercept horizontal sample, length is 5mm-15mm, by sample polish, grinding, polishing, then by alkaline picric acid sodium water solution corrosion for the sample preparing, finally under 500 times of optical microscopes, observe, according to certain principle, net carbide is assessed as to 1 grade, 2 grades, 3 grades, 4 grades, 5 grades.The shape characteristic that this method is 82B wire rod net carbide provides a kind of quantitative assessment method, but still can not be for detection of size and the quantity of carbonide, and in the method, is still and has adopted corrosion treatment operation.

Summary of the invention

For solving the deficiencies in the prior art, the invention provides a kind of method of saving the high V Primary MC Carbide in High Speed Steels of quantitative detection of corrosion treatment operation.

For achieving the above object, the method for the high V Primary MC Carbide in High Speed Steels of quantitative detection of the present invention comprises the following steps:

A, sampling: from steel to be checked, cut the sample that length L is 10-20mm, along center, cut open, getting a semicylinder is sample;

B, sample pretreating: by the central plane sanding and polishing of sample;

C, image acquisition: adopt the backscattered electron probe in scanning electron microscope, 1/8 diameter place central plane, distance center planar radial edge or the image at 1/4 diameter place are gathered;

D, data statistics: adopt metallographic software to analyze picture, obtain MC carbide particle granularity and area occupation ratio data result.

First from steel to be checked, cutting length is that 10-20mm is easy to, by the sample of operating personnel's manual grinding, along center, cut open, obtains semicylinder sample, facilitates follow-up image acquisition; Then pass through mechanical grinding polishing, the impact that the cut problem on elimination sample etc. is analyzed subsequent pictures; In ensuing image acquisition, the irregularity of eutectic carbides > > rating method with reference to GB14979 < < steel, and the impact that is mainly subject to material 1/4,1/8 place's carbide particle size and distributes in conjunction with life of tap, 1/8 diameter place central plane, distance center planar radial edge or 1/4 diameter place are carried out to image acquisition, adopt the backscattered electron probe of scanning electron microscope obtain can clear resolution carbonide backward scattering picture; Finally, according to the contrast difference of the MC carbonide of backscatter images and M6C carbonide, adopt metallographic software to analyze, obtain MC carbide particle granularity and area occupation ratio data result.

Utilization obtains showing the image contrast of microcell chemical composition difference to the backscattered electron signal of sample microcell atomic number or chemical composition change sensitivity as modulation signal, the contrast causing according to atomic number changes, under backscattered electron probe, can distinguish various metals and alloy.Heavy element region is clear zone on image, and light element region is dark space.V is light element with respect to W, Mo, be dark space in the drawings, therefore high V high-speed steel gathers in picture at backscattered electron, can clearly recognize MC carbonide, but scanning electron microscope does not possess image analysis function, must could MC carbonide be extracted and be analyzed in conjunction with metallographic examination software.Compartment analysis by metallographic software to MC carbonide and M6C carbonide contrast, the black white reverse of combining image, the software operation such as cut apart, can obtain granularity and the area occupation ratio data of MC carbide particle, the quantitative test of realization to MC carbonide, and method of operating is easy, quick, testing result is accurate.

As the restriction to aforesaid way, described step b comprises that the emery wheel arranging in turn polishes, pre-mill grinds, craft grinds and polishing process.

Sample only need pass through simple mechanical grinding, polishing, eliminates the cut impact on sample, just can carry out observation analysis, simple to operation, and is difficult for introducing other disturbing factor.

As the restriction to aforesaid way, described step c image acquisition multiple is 700X.

First image acquisition multiple will guarantee that MC carbide particle is clear and legible, and then less the included visual field area of multiple is larger, takes the optimal acquisition multiple of selected 700X into consideration.

As the restriction to aforesaid way, the surface area that described step c image acquisition region is 1mm * 10mm.

1mm * 10mm region area that the image at 1/8 diameter place central plane, distance center planar radial edge or 1/4 diameter place is gathered carries out complete observation, the special area of not selecting to only have a huge carbonide or there is no carbonide completely, gather picture, picture carries out metallographic software analysis, by average method, MC carbide particle granularity and area occupation ratio are added up, the result obtaining thus can be used as the data of evaluating whole steel MC carbonide index to be checked.

In sum, adopt technical scheme of the present invention, provide a kind of and can save the detection method of sample being carried out to corrosion treatment operation, this method utilizes scanning electron microscope to combine with quantitative metallography software analysis, the size and the quantity that detect quickly and accurately MC carbonide, accuracy of detection is high, simple to operate, solved in GB operation due to sample corrosion treatment prolongation running time, the problems such as personal error that testing process produces.

Accompanying drawing explanation

Below in conjunction with the drawings and the specific embodiments, the present invention is done further to describe in detail:

Fig. 1 is the sample structure schematic diagram cutting;

Fig. 2 is sample structure schematic diagram;

Fig. 3 is electron-microscope scanning figure;

Fig. 4 is that electron-microscope scanning figure is by metallographic software black white reverse figure;

Fig. 5 is that metallographic software image is cut apart figure;

Fig. 6 is that metallographic software image is cut apart figure.

In figure: 1, sample; 2, sample; 3, image acquisition region; 4, central plane.

Embodiment

The present embodiment relates to the method for the high V Primary MC Carbide in High Speed Steels of a kind of quantitative detection, and it is example that the method take that M3 high-speed steel annealed state detects, and it specifically comprises the following steps:

A, sampling: on the M3 of φ 16 steel, cutting length L is the sample 1 of 15mm, and its structure as shown in Figure 1, is cut sample open along center, then get that wherein a semicylinder is as sample 2, and its structure as shown in Figure 2;

B, sample pretreating: by specimen surface sanding and polishing, step is as follows successively:

( ) sample is polished on emery wheel;

( ) sample is ground by pre-mill 80# waterproof abrasive paper and 280# waterproof abrasive paper;

( ) use in turn 180#, 280#, 400#, 600#, 800# waterproof abrasive paper to carry out craft to sample to grind;

( ) sample is carried out on buffing machine to polishing, until central plane no marking;

C, image acquisition: adopt the backscattered electron pattern in S-3400N type scanning electron microscope, 1/8 diameter place or 1/4 diameter place to the central plane 4 distance center planar radial edges of sample carry out image acquisition, 1/8 diameter place, distance center planar radial edge as shown in Figure 2, the image acquisition region 3 that is 1mm * 10mm to area gathers image, obtain the electron-microscope scanning figure shown in Fig. 3, it is 700X that image scanning multiple is set;

D, data statistics: adopt the microscopical metallographic software of Olympus GX51 type picture to be carried out to the analysis of MC carbide particle granularity and area occupation ratio.

In MC carbide particle grain size statistics, divide 8 intervals, each interval range is as shown in the table:

MC carbonide area occupation ratio statistics, take the scanning electron microscope (SEM) photograph shown in Fig. 3 as example, and statistic procedure is:

Select the scanning electron microscope (SEM) photograph shown in Fig. 3 to carry out metallographic software analysis; Fig. 3 is carried out to picture inversion operation, obtain the black white reverse figure shown in Fig. 4; Fig. 4 is carried out to image cutting operation, obtain the image shown in Fig. 5 and cut apart figure, count the M6C+MC carbonide total area; Fig. 5 is proceeded to image cutting operation, obtain the image shown in Fig. 6 and cut apart figure, count the area of M6C carbonide; Finally the M6C+MC total area is deducted to M6C area and obtain MC area, thereby calculate the area occupation ratio of MC carbonide.

Through as above detection method, obtain M3 high-speed steel MC carbide particle and distribute and area occupation ratio result, as shown in the table:

Claims

1. quantitatively detect a method for high V Primary MC Carbide in High Speed Steels, it is characterized in that the method comprises the following steps:

B, sample pretreating: by the central plane sanding and polishing of sample;

2. the method for the high V Primary MC Carbide in High Speed Steels of quantitative detection according to claim 1, is characterized in that: described step b comprises that the emery wheel arranging in turn polishes, pre-mill grinds, craft grinds and polishing process.

3. the method for the high V Primary MC Carbide in High Speed Steels of quantitative detection according to claim 1, is characterized in that: described step c image acquisition multiple is 700X.

4. the method for the high V Primary MC Carbide in High Speed Steels of quantitative detection according to claim 1, is characterized in that: the surface area that described step c image acquisition region is 1mm * 10mm.