QE大规格H型钢QElargespecificationHsteel

1、q345e大规格h型钢（q345e large specification h steel）volume 31, stage 2in april 2009,shandong metallurgicalapril2009 shandongmetallurgyvol. 31, no. 2abstract: time limitation of q345e large size h-beam way research found that less influence aging on the impact toughness and 40 , using the energy method to

2、determine the steel brittleness at low temperaturecurve, the brittle transition temperature range for - 30 40 . the analysis of metallographic structure, the macroscopic and microscopic appearance of the fracture and the microscopic appearance of the inclusionsthe analysis of electron probe spectros

3、copy shows that the main causes of low temperature impact toughness are serious banded structure and non-metallic inclusions in steel.key words: h-shaped steel; low temperature impact toughness; aging; banded structure; inclusionsmiddle image classification no. : tg113; tg115 literature identificati

4、on code: a post no. : 1004-4620 (2009) 02-0040-03deadline: 2008-12-23the author: dong changxing, male, born in 1972, graduated from hebei chengde petroleum university in 1994technical college industrial analysis major. now the quality supervision department of lai-steel quality assurance departmentb

5、e engaged in quality inspection of steel products.1 introductionthe q345e large specification h shape steel produced by laishan steel factory is at the beginningfig.5 found to 40 impact akv value is low and volatile,however, after two weeks or so of aging, the akv value increased significantly, most

6、lyseveral furnaces meet product standard requirements. in order to improve the steellow temperature impact toughness and shorten aging time, for product storage, hairthe conditions of the goods and the port are created, and the steel h section steel is tested in seriesand test analysis. by means of

7、different aging methods,hope to find the best way of aging; on the other hand, the macro of impact samplethe distribution and morphology of the fracture, microfracture, tissue morphology and inclusionsanalysis can determine the q345e of large size h-beam and 40 impactfor low reason, the direction of

8、 high temperature impact toughness is determined.2 aging testthe technical requirements of steel q345e large h steel are shown in table 1 and table 2. oftenthe temperature-aging test combines boiling water bath and oil bath with natural agingin the same way, the adverse conditions of temperature and

9、 environmental conditions are carried out. aging testa total of 3 rounds were conducted, with the furnace number h083-3622q345e as the firstthe chemical composition and gas content of the test samples were shown in table 3.table 1 performance requirementsthe specification/mm is less than or equal to

10、 16 or greater than or equal to 345 bbb 0, 16 35 sigma/mpa470 630 delta s / %acuity 22 akv (to 40 , the longitudinal)/j 27 q345e big h-beam and 40 or higher impact toughness is low cause analysisdong changxing, cheng mei, time zhenming, dong bingcheng, liu hongyan(laiwu steel group co., ltd. shandon

11、g laiwu 271104).experimental researchprojectstandardinternal controlc is less than 0.180.13 0.17 si is less than 0.550.15 0.25 mn1.0 1.61.2 1.4 p = 0.025 is less than or less than 0.025, or 0.025, or 0.025, 0.015 0.015 0.025table 2 chemical components control %table 4 impact test data after oil bath

12、oil bath temperature / 120150200280340-40 akv/j42, 84421 0,18,8106,50,1020,128,4222,20,58test temperaturedegree / the normal temperature30-40 -constant temperature of 7d1 #10834322 #13046133 #10810144 #14212105 #138269room temperature of 15d1 #10444462 #11838183 #9634404 #11216385 #1301820table 6. t

13、ime-temperature adverse impact data jwater bath timeno bath30 min45min60min90minthe normal temperature122,92,130116,144,114100,130,128128,120,12696,132,112-30 46,24,4826,48,3028,20,1212,22,1840,38,32-40 26, 14, 2834, 40, 32, 18, 12, 18, 14, 14, 12, 16table 5 water bath after the impact test data jc0

14、.178 si0.214 mn1.26 p0.009 s0.007 cr0.024 nb0.017 ni0.01 cu0.014 al0.005o * 10-654.1n times 10-637.5table 3 samples of chemical composition and gas content %the impact test data after oil bath is shown in table 4 (30min oil bath time). the test data of impact test after water bath is shown in table

15、5 (water bath temperature100 ); under normal temperature (10 30 ) aging impact test data shown in table 6.from a large number of experimental data, the temperature of normal temperature has a basic impactis not affected, 15 d after aging, and 30 and 40 - impact sbent in parisimproved, below 30 impac

16、t energy as a whole is not high and volatile, this masterif it is caused by the release of residual stress; oil bath or water bath quicklythe effect of effect on the impact work has not been significantly beneficialit is not obvious that the impact work under the temperature of temperature is not ob

17、viousto take a water bath or oil bath with the test specimen, and the condition of the permanent temperature of the whole steel40abstract: time limitation of q345e large size h-beam way research found that less influence aging on the impact toughness and 40 , using the energy method to determine the

18、 steel brittleness at low temperaturecurve, the brittle transition temperature range for - 30 40 . the analysis of metallographic structure, the macroscopic and microscopic appearance of the fracture and the microscopic appearance of the inclusionsthe analysis of electron probe spectroscopy shows th

19、at the main causes of low temperature impact toughness are serious banded structure and non-metallic inclusions in steel.key words: h-shaped steel; low temperature impact toughness; aging; banded structure; inclusionsmiddle image classification no. : tg113; tg115 literature identification code: a po

20、st no. : 1004-4620 (2009) 02-0040-03deadline: 2008-12-23the author: dong changxing, male, born in 1972, graduated from hebei chengde petroleum university in 1994technical college industrial analysis major. now the quality supervision department of lai-steel quality assurance departmentbe engaged in

21、quality inspection of steel products.1 introductionthe q345e large specification h shape steel produced by laishan steel factory is at the beginningfig.5 found to 40 impact akv value is low and volatile,however, after two weeks or so of aging, the akv value increased significantly, mostlyseveral fur

22、naces meet product standard requirements. in order to improve the steellow temperature impact toughness and shorten aging time, for product storage, hairthe conditions of the goods and the port are created, and the steel h section steel is tested in seriesand test analysis. by means of different agi

23、ng methods,hope to find the best way of aging; on the other hand, the macro of impact samplethe distribution and morphology of the fracture, microfracture, tissue morphology and inclusionsanalysis can determine the q345e of large size h-beam and 40 impactfor low reason, the direction of high tempera

24、ture impact toughness is determined.2 aging testthe technical requirements of steel q345e large h steel are shown in table 1 and table 2. oftenthe temperature-aging test combines boiling water bath and oil bath with natural agingin the same way, the adverse conditions of temperature and environmenta

25、l conditions are carried out. aging testa total of 3 rounds were conducted, with the furnace number h083-3622q345e as the firstthe chemical composition and gas content of the test samples were shown in table 3.table 1 performance requirementsthe specification/mm is less than or equal to 16 or greate

26、r than or equal to 345 bbb 0, 16 35 sigma/mpa470 630 delta s / %acuity 22 akv (to 40 , the longitudinal)/j 27 q345e big h-beam and 40 or higher impact toughness is low cause analysisdong changxing, cheng mei, time zhenming, dong bingcheng, liu hongyan(laiwu steel group co., ltd. shandong laiwu 27110

27、4).experimental researchprojectstandardinternal controlc is less than 0.180.13 0.17 si is less than 0.550.15 0.25 mn1.0 1.61.2 1.4 p = 0.025 is less than or less than 0.025, or 0.025, or 0.025, 0.015 0.015 0.025table 2 chemical components control %table 4 impact test data after oil bathoil bath temp

28、erature / 120150200280340-40 akv/j42, 84421 0,18,8106,50,1020,128,4222,20,58test temperaturedegree / the normal temperature30-40 -constant temperature of 7d1 #10834322 #13046133 #10810144 #14212105 #138269room temperature of 15d1 #10444462 #11838183 #9634404 #11216385 #1301820table 6. time-temperatu

29、re adverse impact data jwater bath timeno bath30 min45min60min90minthe normal temperature122,92,130116,144,114100,130,128128,120,12696,132,112-30 46,24,4826,48,3028,20,1212,22,1840,38,32-40 26, 14, 2834, 40, 32, 18, 12, 18, 14, 14, 12, 16table 5 water bath after the impact test data jc0.178 si0.214

30、mn1.26 p0.009 s0.007 cr0.024 nb0.017 ni0.01 cu0.014 al0.005o * 10-654.1n times 10-637.5table 3 samples of chemical composition and gas content %the impact test data after oil bath is shown in table 4 (30min oil bath time). the test data of impact test after water bath is shown in table 5 (water bath

31、 temperature100 ); under normal temperature (10 30 ) aging impact test data shown in table 6.from a large number of experimental data, the temperature of normal temperature has a basic impactis not affected, 15 d after aging, and 30 and 40 - impact sbent in parisimproved, below 30 impact energy as a

32、 whole is not high and volatile, this masterif it is caused by the release of residual stress; oil bath or water bath quicklythe effect of effect on the impact work has not been significantly beneficialit is not obvious that the impact work under the temperature of temperature is not obviousto take

33、a water bath or oil bath with the test specimen, and the condition of the permanent temperature of the whole steel40different ways of quick aging of oil bath or water bath are not desirable.determination of temperature range of low temperature brittle transition temperature3.1 low temperature brittl

34、eness curvein order to adjust the composition of q345e steel, it is mainly to adopt healthc, nb, control measures, such as p, s, o content can produce - 40 impact work meets national standards, but it is difficult to operate.it's prone to volatility. in order to assess the current production con

35、ditions q345ethe low temperature impact performance of steel is measured in the laboratorytemperature change curve of low temperature brittleness of shape steel (see figure 1). from figure 1it can be seen that the impact absorption work has two platforms on the curve of temperature changeplatform fo

36、r high shock absorption function part, when the temperature dropped to about 30 ,with the decreasing of temperature, akv fell sharply, when the temperature dropped to 40 in the lower case, the akv changes small and enters the lower platform of low impact absorption work.akv/j - 80-80test temperature

37、 / fig. 1 steel q345eh section steel akv-t curve3.2 macro fracture analysisthe typical macroscopic fracture morphology of a series of temperature shocks is shown in fig. 2, from the roomin the process of temperature drop to - 70 , impact sample from ductile to brittle fracturethe transition of the s

38、exual fracture, the area of the fiber area and the shear labial area gradually dwindled to eliminatethe area of the crystalline region gradually expands to the whole section. 40 to -the lower crispy tendency is severe.room temperature 0 to 30 and 40 figure 2. typical temperature impact of the steel

39、q345eh section steel3.3 microfracture analysisthe microcosmic fracture of the impact of temperature impact on the whole section is in a fortitude.it shows that the steel has high toughness; - 10 when fracture has heartthe crystallization appears in the river pattern; the temperature dropped to - 30

40、, the knotthe crystalline region has expanded to the bottom; to 40 when only small near the gapthe region appears to have a tough fossa, while the rest of the region has a fluvial streakthe levy. the microfracture morphology shows that the temperature of the test is reducedthe fracture mechanism is

41、gradually changed from the fracture of the ductile to cleavage fracture.the microfracture morphology of typical test temperature impact samples is shown in fig. 3shown below.100 mu m100 approximately mu m100 approximately mu m100 approximately micronsat room temperature the core department - 30 to 1

42、0 heart heart department to 40 room temperature near gap area - 10 near gap area - 30 near gap area to 40 near gap areafig. 3 typical temperature impact microfracture morphology of steel q345eh section steel100 mu m100 approximately mu m100 approximately mu m100 approximately micronsthe energy metho

43、d determines the temperature of the low temperature of q345eh steeltemperature range between 30 40 - -. good - 30 when the impact energyand stable, below 30 impact energy fell sharply, and 40 impact energyoverall poor performance, brittle fracture tendency is serious. you can see, by compositionthe

44、whole, and 30 impact energy can guarantee, and below - 30 steel has enteredductile to brittle transition zone, want to ensure a stable qualified to 40 impact energy is difficultis very large. therefore, to further reduce the brittle transition temperature, from the rootto improve the quality of stee

45、l, other technical means should be considered.low temperature impact work and analysis of the cause of fluctuation4.1 metallographic analysissome samples of metallographic tissue observed that ferrite/pearliteq345e big h-beam and 40 low impact toughness of cause analysis dong changxing etc. 200941di

46、fferent ways of quick aging of oil bath or water bath are not desirable.determination of temperature range of low temperature brittle transition temperature3.1 low temperature brittleness curvein order to adjust the composition of q345e steel, it is mainly to adopt healthc, nb, control measures, suc

47、h as p, s, o content can produce - 40 impact work meets national standards, but it is difficult to operate.it's prone to volatility. in order to assess the current production conditions q345ethe low temperature impact performance of steel is measured in the laboratorytemperature change curve of

48、low temperature brittleness of shape steel (see figure 1). from figure 1it can be seen that the impact absorption work has two platforms on the curve of temperature changeplatform for high shock absorption function part, when the temperature dropped to about 30 ,with the decreasing of temperature, a

49、kv fell sharply, when the temperature dropped to 40 in the lower case, the akv changes small and enters the lower platform of low impact absorption work.akv/j - 80-80test temperature / fig. 1 steel q345eh section steel akv-t curve3.2 macro fracture analysisthe typical macroscopic fracture morphology

50、 of a series of temperature shocks is shown in fig. 2, from the roomin the process of temperature drop to - 70 , impact sample from ductile to brittle fracturethe transition of the sexual fracture, the area of the fiber area and the shear labial area gradually dwindled to eliminatethe area of the cr

51、ystalline region gradually expands to the whole section. 40 to -the lower crispy tendency is severe.room temperature 0 to 30 and 40 figure 2. typical temperature impact of the steel q345eh section steel3.3 microfracture analysisthe microcosmic fracture of the impact of temperature impact on the whol

52、e section is in a fortitude.it shows that the steel has high toughness; - 10 when fracture has heartthe crystallization appears in the river pattern; the temperature dropped to - 30 , the knotthe crystalline region has expanded to the bottom; to 40 when only small near the gapthe region appears to h

53、ave a tough fossa, while the rest of the region has a fluvial streakthe levy. the microfracture morphology shows that the temperature of the test is reducedthe fracture mechanism is gradually changed from the fracture of the ductile to cleavage fracture.the microfracture morphology of typical test t

54、emperature impact samples is shown in fig. 3shown below.100 mu m100 approximately mu m100 approximately mu m100 approximately micronsat room temperature the core department - 30 to 10 heart heart department to 40 room temperature near gap area - 10 near gap area - 30 near gap area to 40 near gap are

55、afig. 3 typical temperature impact microfracture morphology of steel q345eh section steel100 mu m100 approximately mu m100 approximately mu m100 approximately micronsthe energy method determines the temperature of the low temperature of q345eh steeltemperature range between 30 40 - -. good - 30 when the impact energyand stable, below 30 impact energy fell sharply, and 40 impact energyoverall poor performance, brittle fracture tendency is serious. you can see, by compositionthe whole, and 30 impact energy can guarantee, and below - 30 steel has enteredductile to brittle transition z