Nitrogen austenite steel microstructure predicting method

A technology of microstructure and prediction method, which is applied in the direction of testing metals, measuring devices, surface/boundary effects, etc., can solve problems such as high cost, and achieve the effect of easy operation, easy maintenance, and easy operation

Inactive Publication Date: 2009-05-06
JIANGSU UNIV +1
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Problems solved by technology

This method can predict the microstructure of nitrogen-containing austenitic steel, guide the developme...

Method used

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  • Nitrogen austenite steel microstructure predicting method
  • Nitrogen austenite steel microstructure predicting method
  • Nitrogen austenite steel microstructure predicting method

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0025] Process such as figure 1

[0026] After the alloying elements are input in the input module, the high temperature δ phase volume fraction calculation module in the calculation module will use the formula

[0027] T δ (℃)=T 4 -21.2[Cr]+15.8[Ni]-223

[0028] Calculation of T for Nitrogen-Containing Austenitic Steels δ temperature, part of the calculation results are shown in Table 1, and according to the formula

[0029] V δ (%)=0.715exp[0.015(T-T δ )]

[0030] The volume fraction of delta phase was calculated. The calculation results are output in the output module.

[0031] Table 1 T of partial austenitic steel δ

[0032]

Embodiment 2

[0034] In the input module, after inputting the alloy composition and temperature, the nitride (Cr 2 N) The grain boundary precipitation time calculation module adopts the formula during isothermal treatment in the middle temperature stage

[0035] lnt s =-9.9+324.8 / (1348-T)+10723.7 / T+89.0Mn / T+130.6Cr / T-171.5Ni / T

[0036] -3241.7(1.2N+C) / T+44.5Mo / T-3701.3V / T

[0037] Calculate the Cr 2 The time when N starts intergranular precipitation. Part of the calculation results are shown in Table 2. It can be seen that there is little difference between the calculation results and the experimental values. Calculation results enter the output module and output.

[0038] Table 2 Cr of some austenitic steels at different temperatures 2 The time for N to start intergranular precipitation

[0039]

[0040]

Embodiment 3

[0042] After entering the alloy composition in the input module, the low temperature ε and α martensite start transformation temperature module in the calculation module, using the formula

[0043] m s (K)=731-227(C+N)-17.6Ni-22.5Mn-17.3Cr-16.2Mo

[0044] m εs (K)=630-261.4(C+N)-13.7Mn-13.1Cr-17.9Ni-38.5A1

[0045] M can be calculated for austenitic steels s and M εs , and some calculation results are shown in Table 3 and Table 4. The calculation result is output to the user through the output module.

[0046] Table 3 M of some materials s The experimental and calculated values ​​of

[0047]

[0048] Table 4 M of some materials εs The experimental and calculated values ​​of

[0049]

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Abstract

The invention relates to a prediction method for the microstructure of martensite steel, which comprises an input module, a computing module and an output module, wherein the computing module comprises a high-temperature delta-phase volume fraction computing module, a start transformation temperature computing module of a low-temperature epsilon and alpha martensite, and a grain boundary start precipitation time computing module when a nitride of Cr2N is in isothermal treatment in a medium temperature phase; the input module has the function of providing parameters input by a user, such as alloy contents, temperature, and the like, the computing module utilizes the input parameters and combines computing formulas to compute, and the output module enables the user to obtain computing results. The method can simplify a material development process, decrease the development cost, increase the development speed, provide reference for the material design of nitrogen austenite stainless steel and technological control, such as heat treatment, forging, and the like, and predict the low-temperature structure stability of the nitrogen austenite stainless steel. The invention also has the advantages of convenient data processing, wider alloy content sphere of application, wider sphere of application, and the like, and is favorable to the application of computing technologies in the field of the material design.

Description

technical field [0001] The invention relates to a method for predicting the microstructure of nitrogen-containing austenitic steel. Background technique [0002] Austenitic stainless steel is the most important type of stainless steel. Its production and usage account for about 70% of the total production and consumption of stainless steel, and the steel grade is also the most. For decades, the most widely used at home and abroad is nickel-chromium stainless steel. But such stainless steel has two more serious problems. Firstly, its low strength and hardness limit its wide use; secondly, because the deposits of nickel and chromium are relatively small, the production cost is high. In response to these problems, people have carried out research on doping nitrogen in austenitic stainless steel, and found that nitrogen can stabilize austenite microstructure and improve strength, and its effect is stronger than that of carbon and other alloying elements. Nitrogen reduces auste...

Claims

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Application Information

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IPC IPC(8): G01N13/00G01N33/20G06F19/00
Inventor 袁志钟戴起勋王安东陈康敏程晓农华杨康纪建国庄建新
Owner JIANGSU UNIV
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