Background technology
Traditional steel inclusion size distribution is to detect by means such as optical microscope, electron probe and visual instrument analyses, and the accuracy of these detection methods is subjected to the influence of sample preparation, proofer's external conditions such as level, and analysis time is long.If end product quality has problem to be caused by snotter, then by the check slab quality, adjust the steel product quality problem of producing after smelting process solves, and can not solve the steel product quality problem of having produced, so the rejection rate height.Surpass certain limit if be mingled with size in the steel, will make steel be easy to generate crackle, its fatigue behaviour significantly descends.And the contour clean steel goods of some steel, particularly wire rod and deep-draw material have strict restriction to inclusion size, therefore require the inclusion size in the online detection steel in smelting process, so that it is controlled in the permissible value scope, produce specification product.In order to address this problem, need exploitation a kind of in each operation such as refining the technology of online detection steel inclusion.
The Jap.P. number of delivering 09-043151 and 09-043150 " inclusion size Determination of distribution method in the metal " disclose the method for a kind of spectral analysis inclusion size distribution of Kawasaki, Japan company.Discharge in a large number at analytical sample and between and select the spectrum line of snotter forming element in the spectral line of emission that is obtained, analyze the AL concentration in being mingled with, be converted into Al then electrode
2O
3Content and its weight become particle diameter by the snotter density conversion again, analyze inclusion size and distribute.The computing method that in disclosed method, do not have AL concentration, and when analyzing, do not carry out pre-arcing.The computing method that do not have maximum inclusion size in addition in the Jap.P..The precision of this method is lower, and analytical approach is also reasonable inadequately.
Summary of the invention
The spectroscopic analysis methods that the purpose of this invention is to provide a kind of spark discharge formula Emission Spectrophotometer, the method of online detection snotter composition and size distribution in analytical element content, directly analyze the assorted intensity of folder thing from original metal element pulse strength and oxygen pulse strength, the snotter number, weight difference before and after exciting by sample again, calculate the weight that each is mingled with, each weight that is mingled with is removed with snotter density, obtain the volume of a Spherical Inhomogeneity thing, be converted into again and be mingled with particle diameter, analyzing the inclusion size that at every turn excites in the sample distributes, carry out 10 times repeatedly and analyze and adopt extreme statistics, calculate the maximum inclusion size in the steel sample.
According to the spectroscopic analysis methods of online detection steel inclusion size distribution of the present invention, formed by the following step:
1) in inert gas environment, carries out pre-arcing and formal spark discharge at the steel sample with between to electrode;
2) with the luminous Emission Spectrophotometer of carrying out metallic element and being mingled with monitoring elements oxygen of each spark discharge, draw metallic element pulse strength figure, oxygen element pulse strength figure and reach intensity chart of frequency distribution separately, determine that metallic element is mingled with critical strength and is mingled with monitoring elements oxygen critical strength;
3) be mingled with the total intensity that number and metallic element are mingled with part by what data processing calculated that this metallic element causes, and calculate inclusion content in the sample with the relation between predefined snotter intensity level and the content;
4) by inclusion content and the evaporation capacity that excites at every turn, calculate the weight that each is mingled with, each weight that is mingled with is removed with snotter density, obtain the volume of a Spherical Inhomogeneity thing, the snotter volume is converted into particle diameter, analyzes the inclusion size that at every turn excites in the sample and distribute;
5) carry out aforesaid operations repeatedly, at least 10 times, determine the size distribution of snotter in the test button;
6) adopt extreme statistics to calculate maximum inclusion size in the sample;
According to the spectroscopic analysis methods of online detection steel inclusion size distribution of the present invention, described pre-arcing will be carried out 200-700 pulse, and formal spark discharge will be carried out 1500-2000 pulse:
According to the spectroscopic analysis methods of online detection steel inclusion size distribution of the present invention, described definite metallic element is mingled with the critical strength method and is: draw this metallic element intensity chart of frequency distribution, and in this distribution plan, intensity I
m± k σ is that metallic element is mingled with critical strength I
k, I wherein
mIntensity during for maximum frequency, k=1.5, σ are metallic element intensity mean square deviation;
According to the spectroscopic analysis methods of online detection steel inclusion size distribution of the present invention, describedly determine that the method that is mingled with monitoring elements oxygen critical strength is: draw oxygen element intensity chart of frequency distribution, in this distribution plan, intensity I
o± k
oσ is for being mingled with monitoring elements oxygen critical strength I
N, I wherein
oIntensity during for maximum frequency, k=1.5, σ are oxygen intensity mean square deviation.
According to the spectroscopic analysis methods of online detection steel inclusion size distribution of the present invention, its specific implementation process is made up of (with Al the following step
2O
3Be mingled with and be example):
1) in the inert gas environment in luminous (2), at the steel sample with carry out the pre-arcing of 200-700 pulse between to electrode, carries out the formal spark discharge of 1500-2000 pulse again;
2) the luminous of each spark discharge carried out the spectrum line that beam split obtains each element in light-dividing device (1), the pulse strength figure, the oxygen pulse strength figure that draw metallic element aluminium in calculation apparatus (5) reach intensity chart of frequency distribution separately, determine that aluminium is mingled with critical strength and is mingled with monitoring elements oxygen critical strength;
3) count Al by data processing
2O
3Be mingled with number and Al
2O
3Total intensity, and use predefined Al
2O
3The calibration curve that is mingled with between intensity level and the content calculates Al in the sample
2O
3Content;
4) by Al
2O
3Content and the evaporation capacity that at every turn excites calculate each Al
2O
3The weight that is mingled with is with each Al
2O
3The weight that is mingled with is removed with snotter density, obtains a spherical Al
2O
3The volume that is mingled with is converted into particle diameter again, analyzes the Al that at every turn excites in the sample
2O
3Be mingled with size distribution;
6) carry out aforesaid operations repeatedly, at least 10 times, determine Al in the steel
2O
3The size distribution that is mingled with;
7) by adopting extreme statistics to calculate maximum Al in the sample
2O
3Be mingled with particle diameter
In the method for the invention, will carry out pre-arcing before formal spark discharge, purpose is that the exotic attached to specimen surface is removed, and improves accuracy of detection; Adopt extreme statistics to make the check of the maximum inclusion size in the sample more accurate; Because analytical approach is directly to analyze snotter intensity from original metal element pulse strength and oxygen pulse strength, so analysis speed is fast.
Adopt method of the present invention in analytical element content, can measure inclusion size distribution in the test button quickly and accurately.Realize line Quality Control, improve product percent of pass, reduce cost.
Embodiment:
Below in conjunction with description of drawings the specific embodiment of the present invention, here only to analyze Al in the automobile slab
2O
3Be mingled with and be example.
Adopt device as shown in Figure 4, the spectroscopic analysis methods of online detection steel inclusion size distribution is made up of the following step:
1) in the inert gas environment in luminous (2), at the steel sample with carry out the pre-arcing of 200-700 pulse between to electrode, carries out the formal spark discharge of 1500-2000 pulse again;
2) the luminous of each spark discharge carried out the spectrum line that beam split obtains each element in light-dividing device (1), in calculation apparatus (5), draw metallic element aluminium and be mingled with critical strength and be mingled with monitoring elements oxygen critical strength.As Fig. 1, Fig. 2 and shown in Figure 3;
3) count Al by data processing
2O
3Be mingled with number and Al
2O
3Total intensity, and use predefined Al
2O
3The calibration curve that is mingled with between intensity level and the content calculates Al in the sample
2O
3Content is by device (4) output analysis result;
4) by Al
2O
3Content and the evaporation capacity that at every turn excites calculate each Al
2O
3The weight that is mingled with is with each Al
2O
3The weight that is mingled with is removed with snotter density, obtains a spherical Al
2O
3The volume that is mingled with is converted into particle diameter again, analyzes the Al that at every turn excites in the sample
2O
3Be mingled with size distribution, analysis result is divided by device (4) output;
5) carry out aforesaid operations repeatedly, at least 10 times, determine Al in the steel
2O
3The size distribution that is mingled with, Fig. 5 shows Al in the measured steel of the inventive method
2O
3Be mingled with the comparison of size distribution and metaloscope analysis result, as can be seen from Figure 5, the Al of two kinds of methods analysts
2O
3It is rather consistent to be mingled with size distribution.
6) by adopting extreme statistics to calculate maximum Al in the sample
2O
3Inclusion size.Table 1 is for after spectral analysis is mingled with particle diameter, the maximum Al that adopts extreme statistics to calculate again
2O
3Be mingled with particle diameter cooperates analysis result with chemistry, metallographic method comparison, as can be seen from Table 1, both basically identicals as a result.
Method of the present invention is applicable to analyzes Al in the steel
2O
3, SiO
2, inclusion size distributional analysis such as MnO, CaO, MnS.
Two kinds of analytical approach results of table 1 relatively
| ??????????????Al
2O
3Maximum particle diameter μ m
|
Spectral analysis | ????24 | ????20 | ????27 | ????31 | ????17 |
Chemistry, metallographic examination | ????26 | ????19 | ????25 | ????29 | ????16 |