Relationship between Phase Structure Factor and C-curve Characteristic Point of Cr, Mn Low Alloy Structural Steel

The state of hybridization of each atom in the crystal whose crystal lattice constant is known and the distribution of covalent electrons on the bond formed between them are calculated, and the state of the atom and the covalent electron distribution on the bond are calculated as the crystal. Valuable electronic structure. Since the theory was published, many electronic structural parameters of mechanical dynamics and mechanical properties are collectively referred to as phase structure factors. The phase structure factor refers to the covalent electron logarithm on the strongest covalent bond in a structural unit; the phase structure factor is called the bond-bonding ability of a carbon-containing bond, which means the other atoms and carbon in a certain carbon-containing structural unit. The sum of the product of the number of covalent electrons on all covalent bonds formed by an atom and the bondability of the two atoms that make up the bond, ie, the number of covalent electrons on the bond, and the difference in the bond length from The analysis shows that 6 is the arithmetic average of the bonding abilities of the two atoms that make up the 1 bond.

Austenite is composed of 7 unit cells and a unit cell containing yttrium. After addition of alloying element 6, it is increased by the unit cell. The theory of microscopic inhomogeneity of solid solution in modern times points out that when the binding force between heteroatoms 8 is greater than the binding force between the same kind of atoms, the solute atoms will be distributed in short-range order according to a fixed rule. Document 4 uses the covalent bond covalent electron logarithm 1998仞16 Received, 1999 Must, 9 Received revised manuscript Granted by the National Natural Science Foundation of China Grant No. 531060 Amount of interatomic binding force, based on the unit cell bond and The fact that the bonds of the unit cells of the river 6 are all greater than the value of the 76-cell unit assume that both the original 1 and the atoms in the austenite are in a segregated state, and this segregation region is defined as CFef segregation and CMe segregation, this speculation has been experimentally confirmed 5l. The literature 2, 4, 5 in a variety of alloy steel austenite valence electron structure calculation results and their curves after the proposed core segregation resistance to phase change, This interaction of resistance and driving forces can change the microstructure and properties of the phase transition kinetic phase change products of the alloy. The resistance of centimeters to phase transitions originates from the binding of the strong grid formed by the covalent bonds in the segregation zone caused by the strong binding force of the bond to the movement of the surrounding homes. If it is considered that the supercooled austenite fraction relieves the lattice reconstruction of 66, the 6-bond reconstitution contacts 6630 and KW 3 of the carbon-containing unit cell must be disassembled, and the effect of segregation on the solid-state phase transition must be removed. It will be self-evident. In austenite, the larger the value of the segregation structural unit, the less likely the bond of the structural unit to be disassembled, the greater the resistance to the transformation of undercooled austenite, and the driving required for the transformation of the segregation zone. The greater the degree of coldness. If 1 segregates in the structural unit, less than 6 segregated monogermanium, then the river; segregation in the subcooling degree of 6 and 6 segregation can start the pearlite transformation, so the elbow; segregation of the alloy 1 The curve forms a river bay in the upper part; if so, segregation occurs at a subcooling degree higher than 10 segregation, and the bainite transformation starts, so that the alloy is segregated at 06. The curve forms a river bay in the lower part. The greater the enthalpy of the segregation unit, the greater the binding of the atom to the helium atom, and the longer the gestation period of the heart+transition-diffusion phase transition controlled by the atom diffusion and the semi-diffusion phase transition of the long-term 8 transition. The greater the weight of the center Me segregation structural unit A, the more pronounced this effect of F is. This is a qualitative description of the relationship between the phase structure factor and the curve of the metameric structure of CMe in the literature 2, 4, and 5.

If the relationship between the temperature of 7,7 and the shortest incubating period of the component phase structure factor factory and its weighted nose is established, the steel of the specific component can be theoretically determined. The position of the nose of the curved nose and the shortest incubating period to ascertain the hardenability of the steel to determine the critical cooling rate of the steel and related processing techniques. This article made a preliminary attempt here.

Type is similar to this, except that the position of 6 is still the same. Since each segregation structure unit in austenite contains only one carbon atom, the percentage of carbon atoms defined by certain segregation structure units is defined as the weight of the segregation structure unit in the steel.

In the austenitizing process, if the original elements of carbon and alloy elements can fully diffuse the number of segregation structural units and segregation structural units should be related to the bonding force between the atoms therein. The more stable the segregation structural unit, the stronger the bonding force, and the greater the number of equilibrium components. The phase structure factor in the segregation structure unit is the valence-electricity wide structural parameter of whether the structure of the bond strength is stable or not. For a solid solution of a given composition, the more stable the segregation structural unit is, the more difficult it is for the atoms of the alloying element to diffuse out of the solid solution, and the greater the number of equilibrium constituents, the larger the value of the 1-valued segregation structure unit in the solid solution. The weight should also be greater; obviously, the atomic percentage of some alloying element is 4! The larger the percentage 4 containing unit cells is, the greater the probability of forming a BP3 segregation structural unit with a carbon atom, and the greater the weight of the formed PCT 6 segregation unit in a solid solution. Therefore, it can be assumed that for a unit alloy containing 4 atomic percent of alloying elements, the segregation structure unit is located in these segregation units, and each austenite unit cell contains 4 metal atoms. , so the state of the atom can be formed, 4 unit cells. Press 1 model, PCT! There are 3, 6 atoms, and 1 atoms in the segregation structural unit. So there are pools in these unit cells! The 4 alloys containing only 4 elements contain iron. According to formula 1, when the alloy elements and carbon contents in the proper steel structure of solution equation 34 are changed, not only the value of elbow 6 segregation structural unit value of the equivalent electronic structure changes 5, but also by 5 formula. It is inferred that its weight has also changed. Both changes will affect the position of the curve.

2 The relationship between the nose temperature and ash of the 0 curve of chromium steel manganese steel Compared with the CFef segregation structure unit, this segregation structural unit is more difficult to be disassembled into aFe and Fe3C, making manganese steel larger than carbon steel. The degree of undercooling only occurs, and the larger value of the elbow segregation structure unit also shifts the human 13 to a lower temperature gradient 6. The greater the weight of the core segregation structural unit, the more pronounced this effect is. This is the reason why people discovered in the experiment that the curve of carbon steel is shifted down. In general, if Mn is fully dissolved in austenite, the manganese in the steel is added as an alloying element to make the manganese steel curve appear in the river channel. For the existing 1565, manganese steel statistics of its actual measured human transition and 8 transitions of the nose temperature 7 and its calculation 1. The results are plotted as 2 experimental points. The 7-relationships are assumed to be 8 functions such as exponential logarithmic linear hyperbolic power function. After proper transformation, linear regression is performed by least-multiplication, and the optimal function relationship obtained is the 67-regression correlation coefficient is 0.999 5 respectively. And 0.9987 to prove the reliability of the plant's two functional relationships. Comparison of measured results and calculated curves

For Cr-containing structural steels containing less than 0.6 carbon, the 0 segregation structural unit 5 causes the Cr steel to undercool the austenite at a lower temperature than the carbon steel, ie higher temperature. The shift 6. and the greater the weight of the core segregation structural unit, the more pronounced this effect. This is the effect that the transformation of the person 48 is shifted downward by shifting the core curve into the upward shift in the alloy steel book. For existing chromic steels containing 0.200.60. stats for their actual measurements, the conversion and 48 transitions of the nose temperature 7 were calculated and calculated. Alas, the results are plotted as 3 experimental points. The correlation between the best function of the 7 and 4 knowledge of the chrome steel regressed by the above method is the 89 type regression. The correlation coefficients are 0.999 8 and 0.9995 respectively. The comparison between the measured results and the calculated curves is 3.

3 The relationship between the shortest incubating period of chrome steel manganese steel 0 curve and corpse patience Calculated in the austenitic body of all elbow 6 segregated structural units, the ratio is greater than that of the segregation structural unit, so Cr, Mn plus per capita To shift the C curve of carbon steel to the right, that is to say, to make the shortest incubating period longer, this is the same as the shortest incubating period that people actually derived from the experiment and calculated it, and the result is plotted as 4 experimental points. The cadaveric best-function relationship of the above-mentioned carbon content range of the chromium steel manganese steel regressed by the above method is ten formulas, and the correlation coefficient of the regression is respectively 9842 and 0.9637, and the comparison between the actual measurement results and the calculated curves.

Chromium 4 chromium steel manganese steel; punching relationship is calculated, Lu is the measured value of chromium steel, so that the measured value of manganese steel 4 chromium manganese steel curve nose temperature and the shortest incubating period is predicted due to the alloying element content of low alloy structural steel 5 Chromium-manganese steel contains only two alloying elements. It is convenient for discussion. It does not consider the interaction between alloying elements, ie, the role of segregation structural units in chromium-manganese steels is neglected. Then the chromium-manganese steel with carbon content is determined. The C curve is only determined by the interaction of the CCr segregation structure unit and the CMn segregation structure unit. Due to the different effects of chromium manganese on the temperature of the nose of the curve, it can be assumed that the temperature of the curvilinear nose of the chromium manganese steel is the same as the average carbon content of the chromium steel and the average carbon content of the manganese steel. Value; due to chromium and manganese all make the curve the shortest incubating period, it can be assumed that the shortest incubating period of chromium manganese steel is the corresponding addition of the shortest incubating period of chromium steel manganese steel, that is, for the current, low alloy chromium manganese steel, according to 6 Calculate the temperature and the shortest incubating period of the corresponding manganese steel chromium steel curve nose, according to the 1213 type prediction of chromium manganese steel, the corresponding data of the curve, the theoretical calculation results and the actual measurement results Comparison of the steel number measured value calculated value The actual measured value of the measured value 3 is cited in the literature 7 10. The maximum deviation between the predicted shortest inoculation period and the actual measured value is 1.6 because the austenitizing temperature holding time heating speed of the sample in the original state of the grain size and other factors are It will cause the heart curve to fluctuate within a certain range, and such deviation is acceptable. However, the prediction deviations of the 20CrMn and 35CrMn steels are greater than the maximum deviation of the nasal T temperature is 39, and the maximum deviation of the shortest incubation period is 2.13. Note that the curves of the two steels are respectively after austenitizing at 870 and 825. Measured 7, and its standard austenitizing temperature points are 9, and 8708, so both of these curves were measured under insufficient austenitizing conditions. Due to the low heating temperature, the alloying elements do not fully dissolve into the austenite, and the weight RM of the actual CMe segregation structural unit in the austenite is lower than the theoretical value, and the characteristic points predicted by the theoretical weights have a large deviation from the actual ones. The prediction methods proposed in this paper can sensitively reflect the influence of valence electron structure parameters and the weights of the segregation structural units on the curves.

5 Discussion The 77-sum prediction just confirms that the curve of the alloy steel proposed in Document 9 is the superposition of the heart curve determined by various segregation structural units in austenite. Moreover, the method used for this calculation and its prediction can be directly used as a parameter of the electronic structure of ad valorem, and the quantitative design method of the characteristic point of the curve can be performed. That is, after calculating the valence electron structure parameters of the 06 segregation structural unit in the austenite by the Coulomb 1 theory, the weights of various alloying elements in different alloying elements in the elementary alloy steel are calculated by using the formula 5, and reference is made to the existing ones. Based on the experimental data of the curve, a variety of meta-alloy steels are established on the basis of 7,7,take,1,etc., and the effect of curves is superimposed on all the alloy elements in the steel by analogy with the formulae 12 and 13 so as to realize all the elements and even multiple elements. Prediction of Heart Curve Characteristic Point of Low Alloy Structural Steels .