Method for predicting roll life based on roll hardness

Abstract

The present invention discloses a method for predicting the life of a roll based on the hardness of a roll, comprising: establishing a mathematical relationship between the hardness of a roll and the life of a roll; obtaining the fatigue limit N1 of the roll under an alternating stress P1 when the roll has an initial Shore hardness Hs0 according to the mathematical relationship; and obtaining the Shore hardness Hs1 of the roll used for n1 times according to the fatigue damage accumulation hypothesis and the mathematical relationship; and obtaining the Shore hardness Hs2 of the roll under an alternating stress P1 by analogy. k Next and loop using n k The Shore hardness of the roller after the rolling process is Hs k ; Finally, the mathematical relationship between the Shore hardness of the roller and different alternating stresses and the number of cycles is derived. The method of the present invention studies the relationship between the Shore hardness of the roller and the fatigue life of the roller, thereby extending the life of the roller by improving the hardness of the roller, thereby reducing the production cost of the enterprise; the prediction result of the prediction method of the present invention is less different from the actual result, which proves that the prediction method of the present invention has a good prediction effect.

Description

Technical Field

[0001] The invention belongs to the technical field of roller performance evaluation, and in particular relates to a method for predicting roller life based on roller hardness. Background Art

[0002] In the actual production process, if the hardness of the roll is too high, the roll is easy to break during the production process, resulting in high production costs, and the roll is also prone to falling off and breaking during use; if the hardness of the roll is too low, the roll will cause severe wear during actual use, increasing the production cost of the enterprise.

[0003] Therefore, studying the influence of roll hardness on life relationship so as to provide steel rolling enterprises with cost-effective rolls is a technical problem that needs to be solved urgently in this field. Currently, no relevant literature reports have been found. Summary of the invention

[0004] The purpose of the present invention is to solve the above-mentioned problem and provide a method for predicting the life of a roll based on the roll hardness.

[0005] The technical solution to achieve the purpose of the present invention is: a method for predicting the life of a roll based on the hardness of the roll, comprising the following steps:

[0006] ① Establish the mathematical relationship between roll hardness and roll life:

[0007]

[0008] Where: N is the fatigue life of the roller, the unit is times; Hs is the Shore hardness of the roller; P is the alternating stress, the unit is kgf / mm 2 .

[0009] ② According to the mathematical relationship established in step ①, the fatigue limit N1 of the roller under the alternating stress P1 at the initial Shore hardness Hs0 is obtained as follows:

[0010]

[0011] According to the fatigue damage accumulation hypothesis, the fatigue limit N1' after n1 cycles is:

[0012]

[0013] According to the mathematical relationship established in step ①, the Shore hardness Hs1 of the roller after being recycled for n1 times is obtained as follows:

[0014]

[0015] It is then obtained that after being used for n1 times in a cycle, the change in Shore hardness of the roller is: ΔHs1=Hs1-Hs0.

[0016] ③ According to the mathematical relationship established in step ①, the fatigue limit N2 of the roller under the alternating stress P2 at Shore hardness Hs1 is obtained as:

[0017]

[0018] According to the fatigue damage accumulation hypothesis, the fatigue limit N2' after n2 cycles is:

[0019]

[0020] According to the mathematical relationship established in step ①, the Shore hardness Hs2 of the roller after being recycled for n2 times is obtained as follows:

[0021]

[0022] It is then obtained that after being recycled for n2 times, the change in Shore hardness of the roller is: ΔHs2=Hs2-Hs1.

[0023] ④ Similarly, according to the mathematical relationship established in step ①, the Shore hardness Hs of the roller is obtained. k-1 When the alternating stress P k Fatigue limit N k for:

[0024]

[0025] According to the fatigue damage accumulation hypothesis, the cycle time is n k The fatigue limit after N k 'for:

[0026]

[0027] According to the mathematical relationship established in step ①, the roller cycle n is obtained. k Shore hardness Hs after k for:

[0028]

[0029] Then we can get the cycle usage n k After times, the Shore hardness change of the roller is: ΔHs k =Hs k -Hs k-1 .

[0030] ⑤Finally, the mathematical relationship between the Shore hardness of the roller and different alternating stresses and the number of cycles is derived:

[0031]

[0032] Where ΔHsi For the alternating stress P i Next, loop using n i The hardness change after the test.

[0033] The present invention has positive effects: the method of the present invention studies the relationship between the Shore hardness of the roll and the fatigue life of the roll, thereby extending the life of the roll by improving the hardness of the roll, thereby reducing the production cost of the enterprise. The prediction result of the prediction method of the present invention is slightly different from the actual result, which proves that the prediction method of the present invention has a good prediction effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 This is a hardness change diagram predicted by the prediction method of the present invention; wherein the upper curve represents the initial Shore hardness of the roller, and the lower curve represents the predicted Shore hardness.

[0035] Figure 2 It is a comparison diagram of the predicted result and the actual result of the present invention; wherein, the upper curve represents the predicted Shore hardness, and the lower curve represents the actual detected Shore hardness. DETAILED DESCRIPTION

[0036] (Example 1)

[0037] The method for predicting the life of a roll based on the roll hardness of this embodiment is as follows:

[0038] Establish the mathematical relationship between roll hardness and roll life:

[0039]

[0040] Where: N is the fatigue life of the roller, the unit is times; Hs is the Shore hardness of the roller; P is the alternating stress, the unit is kgf / mm 2 .

[0041] According to the mathematical relationship established above, it is predicted that the roller will be subjected to an alternating stress of 100 kgf / mm 2 , 200kgf / mm 2 、300kgf / mm 2 , 400kgf / mm 2 、500kgf / mm 2 (i.e. P1~P5) and the hardness changes after 1000, 2000, 3000, 4000 and 5000 cycles (i.e. n1~n5) respectively. The results are shown in Figure 1 .

[0042] At the same time, compared with the actual test hardness, the results are shown in Figure 2 .

[0043] Depend on Figure 2It can be seen that the prediction results of the prediction method of the present invention are slightly different from the actual results, which proves that the prediction method of the present invention has a good prediction effect.

Claims

1. A method for predicting roll life based on roll hardness, characterized in that The following steps are involved: ① Establish the mathematical relationship between roll hardness and roll life: Where: N is the fatigue life of the roller, the unit is times; Hs is the Shore hardness of the roller; P is the alternating stress, the unit is kgf / mm 2 ; ② According to the mathematical relationship established in step ①, the fatigue limit N1 of the roller under the alternating stress P1 at the initial Shore hardness Hs0 is obtained as: According to the fatigue damage accumulation hypothesis, the fatigue limit N1' after n1 cycles is: According to the mathematical relationship established in step ①, the Shore hardness Hs1 of the roller after being recycled for n1 times is obtained as follows: Then, after the roller is used for n1 times, the change in Shore hardness is: ΔHs1 = Hs1 - Hs0; ③ According to the mathematical relationship established in step ①, the fatigue limit N2 of the roller under the alternating stress P2 at the Shore hardness Hs1 is obtained as: According to the fatigue damage accumulation hypothesis, the fatigue limit N2' after n2 cycles is: According to the mathematical relationship established in step ①, the Shore hardness Hs2 of the roller after being recycled for n2 times is obtained as follows: Then, after the roller is used for n2 times, the change of the Shore hardness is: ΔHs2 = Hs2 - Hs1; ④ Similarly, according to the mathematical relationship established in step ①, the Shore hardness Hs of the roller is obtained. k-1 When the alternating stress P k Fatigue limit N k for: According to the fatigue damage accumulation hypothesis, the cycle time is n k Fatigue limit N k 'for: According to the mathematical relationship established in step ①, the roller cycle n is obtained. k Shore hardness Hs after k for: Then we can get the cycle usage n k After times, the Shore hardness change of the roller is: ΔHs k =Hs k -Hs k-1 ; ⑤Finally, the mathematical relationship between the Shore hardness of the roller and different alternating stresses and the number of cycles is derived: Where ΔHs i For the alternating stress P i Next, loop using n i The hardness change after the test.

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