51CrV4弹簧钢中的夹杂物对其性能的影响
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摘要
本文以四种成分均符合欧标要求的高速列车用弹簧钢51CrV4为研究对象,重点研究钢中夹杂物对其力学性能的影响。通过控制钢中Al、S、O等杂质元素的含量,制备具有不同夹杂物类型和数量的四种钢。利用Formastor-F热膨胀仪测试钢的CCT曲线,研究钢的相变特性；依据标准DIN 50602对钢中的夹杂物类型及等级予以评定；测试了钢的冲击、拉伸、硬度等常规力学性能,利用超声波疲劳试验机测试其中夹杂物含量与类型均不同的两种钢的疲劳性能。
相变特性研究结果表明：1#钢的Ac3为754℃,Ac1为714℃；2#钢的Ac3为750℃,AC1为715℃；3#钢的Ac3为780℃,Ac1为720℃；JK钢的Ac3为766℃,Ac1为669℃；当以高于5℃／s的冷却速度冷却时,四种钢得到的组织主要为马氏体；当升温速度从0.05℃／s提高到50℃／s时,四种钢的Ac3、Ac1均有所升高。
常规力学性能测试研究表明：夹杂物等级在K3=62.5以内,随着夹杂物含量的增高,硬度值呈下降趋势；硫化物夹杂的含量对51CrV4钢的拉伸性能影响不明显；随着形貌为细长链状的夹杂的含量的增加,51CrV4钢的冲击性能呈下降趋势。
超声疲劳研究结果表明：JK钢存在传统的疲劳极限,为675MPa,而1#钢则不存在。经推算,1#钢的疲劳极限为432.4MPa,可见JK钢的疲劳极限明显高于1#钢。JK钢中的硬质夹杂物尺寸小于其临界夹杂物尺寸4.05μm,故其疲劳断裂起源于表面基体；1#钢中的氧化物夹杂平均尺寸为51.7μm,远大于其夹杂物临界尺寸4.13μm,故其疲劳断裂起源于夹杂物；JK钢中的硫化物夹杂含量高于1#钢中的,两种钢均未出现沿硫化物夹杂起裂的疲劳断口,可见,硫化物夹杂的含量对钢的疲劳极限影响不大。
In this paper, four kinds of 51CrV4 whose components are in line with the European standard requirements were as the object of study. Effect of the inclusions in steel to the mechanical properties of steel was studied. By controlling the contents of impurity elements such as Al, S, O, steels with different types and contents of inclusions were produced. Phase transformation character of the four kinds of 51CrV4 was investigated. CCT curves were measured by using the equipment of Formastor-F. According to European standard DIN 50602, the types and grades of inclusion were assessed. The conventional mechanical properties of four steels were tested, such as impact, tensile, hardness. The fatigue properties of two steels in which the types and contents are both different were measured by using the Shimadazu USF-2000 ultrasonic fatigue test machine.
The results of phase transformation character show that the Ac3 and Ac1 of 1# steel are respectively 754℃and 714℃; the Ac3 and Ac1 of 2# steel are respectively 750℃and 715℃; the Ac3 and Ac1 of 3# steel are respectively 780℃and 720℃; the Ac3 and Ac1 of 1# steel are respectively 766℃and 669℃. When the cooling rate is faster than 5℃/s, the microstructure of four steels are all martensite. The Ar3 and Arl are all increased when the heating rate increases from 0.05℃/s up to 50℃/s
The results of conventional mechanical properties testing show that when the content of inclusion is under the K3=62.5, the hardness value decline with the content of inclusions increased. The tensile properties has nothing to do with the content of sulfide inclusion; With the content of inclusion which is thin and long increased, the impact properties of the material of 51CrV4 decreased.
The results of Utlrasonic fatigue testing show that the traditional fatigue limit of JK exist, and its value is 675MPa, but that of 1# does not. Under the projection, the fatigue limit of 1# is 432.4MPa. It's obvious that the fatigue limit of JK is higher than that of 1#. Because the size of hard inclusion of JK is smaller than its critical size of 4.05μm, the origin of fatigue fracture is in surface matrix. But the size of the oxide inclusion of 1# is much large than its critical size of 4.13μm, so the origin of fatigue fracture is the inclusions; The content of sulfide in JK is higher than that in 1#, but there's no fatigue fracture in which the origin is the sulfide inclusion, so it shows the fatigue limit does not depend on the content of sulfide.
相变特性研究结果表明：1#钢的Ac3为754℃,Ac1为714℃；2#钢的Ac3为750℃,AC1为715℃；3#钢的Ac3为780℃,Ac1为720℃；JK钢的Ac3为766℃,Ac1为669℃；当以高于5℃／s的冷却速度冷却时,四种钢得到的组织主要为马氏体；当升温速度从0.05℃／s提高到50℃／s时,四种钢的Ac3、Ac1均有所升高。
常规力学性能测试研究表明：夹杂物等级在K3=62.5以内,随着夹杂物含量的增高,硬度值呈下降趋势；硫化物夹杂的含量对51CrV4钢的拉伸性能影响不明显；随着形貌为细长链状的夹杂的含量的增加,51CrV4钢的冲击性能呈下降趋势。
超声疲劳研究结果表明：JK钢存在传统的疲劳极限,为675MPa,而1#钢则不存在。经推算,1#钢的疲劳极限为432.4MPa,可见JK钢的疲劳极限明显高于1#钢。JK钢中的硬质夹杂物尺寸小于其临界夹杂物尺寸4.05μm,故其疲劳断裂起源于表面基体；1#钢中的氧化物夹杂平均尺寸为51.7μm,远大于其夹杂物临界尺寸4.13μm,故其疲劳断裂起源于夹杂物；JK钢中的硫化物夹杂含量高于1#钢中的,两种钢均未出现沿硫化物夹杂起裂的疲劳断口,可见,硫化物夹杂的含量对钢的疲劳极限影响不大。
In this paper, four kinds of 51CrV4 whose components are in line with the European standard requirements were as the object of study. Effect of the inclusions in steel to the mechanical properties of steel was studied. By controlling the contents of impurity elements such as Al, S, O, steels with different types and contents of inclusions were produced. Phase transformation character of the four kinds of 51CrV4 was investigated. CCT curves were measured by using the equipment of Formastor-F. According to European standard DIN 50602, the types and grades of inclusion were assessed. The conventional mechanical properties of four steels were tested, such as impact, tensile, hardness. The fatigue properties of two steels in which the types and contents are both different were measured by using the Shimadazu USF-2000 ultrasonic fatigue test machine.
The results of phase transformation character show that the Ac3 and Ac1 of 1# steel are respectively 754℃and 714℃; the Ac3 and Ac1 of 2# steel are respectively 750℃and 715℃; the Ac3 and Ac1 of 3# steel are respectively 780℃and 720℃; the Ac3 and Ac1 of 1# steel are respectively 766℃and 669℃. When the cooling rate is faster than 5℃/s, the microstructure of four steels are all martensite. The Ar3 and Arl are all increased when the heating rate increases from 0.05℃/s up to 50℃/s
The results of conventional mechanical properties testing show that when the content of inclusion is under the K3=62.5, the hardness value decline with the content of inclusions increased. The tensile properties has nothing to do with the content of sulfide inclusion; With the content of inclusion which is thin and long increased, the impact properties of the material of 51CrV4 decreased.
The results of Utlrasonic fatigue testing show that the traditional fatigue limit of JK exist, and its value is 675MPa, but that of 1# does not. Under the projection, the fatigue limit of 1# is 432.4MPa. It's obvious that the fatigue limit of JK is higher than that of 1#. Because the size of hard inclusion of JK is smaller than its critical size of 4.05μm, the origin of fatigue fracture is in surface matrix. But the size of the oxide inclusion of 1# is much large than its critical size of 4.13μm, so the origin of fatigue fracture is the inclusions; The content of sulfide in JK is higher than that in 1#, but there's no fatigue fracture in which the origin is the sulfide inclusion, so it shows the fatigue limit does not depend on the content of sulfide.
引文
[1]袁晓玲.钢铁材料手册(第8卷)弹簧钢.北京：冶金工业出版社,2004
[2]董翰.合金钢的现状与未来.中国冶金,1996(6)：29.
[3]中国钢铁工业协会.2005年和2010年优型材需求预测.中国钢铁业,2004,(1)：31-35.
[4]弹簧行业“十五”发展规划.弹簧工程,2002,(72)：36.
[5]张世中.钢的过冷奥氏体转变曲线图集[M].冶金工业出版社,1982.
[6]林慧国,傅代直.钢的奥氏体转变曲线原理、测试与应用[M].机械工业出版社,1988.
[7]DIN50602-1985,特殊钢中非金属夹杂物评级[S].
[8]李代锺.钢中非金属夹杂物[M].北京：科学出版社.1983.56.
[9]惠卫军,董翰,曾新光等.超纯洁弹簧钢.钢铁,1999,34(9)：68-72.
[10]申少华,刘国林,韦弦等.中厚钢板中的硫化物夹杂及其对冷弯性能的影响[J].宽厚板,2005,11(2)：26-30.
[11]惠卫军,董瀚,陈四联.非金属夹杂物和表面状态对高强度弹簧钢疲劳性能的影响[J].特殊钢,1998,19(6)：8-14.
[12]张德堂.钢中非金属夹杂物鉴别[M].北京：国防工业出版社,1994．283.
[13]lankford J. International Metals Reviews,1997, (9):221.
[14]殷瑞钰主编.钢的质量现代进展(下篇·特殊钢)[M].北京：冶金工业出版社,1995.99.
[15]杨振国,张继明,李守新等.高周疲劳条件下高强度钢临界夹杂物尺寸估算[J].金属学报,2005,41(11)：1136-1142.
[16]聂义宏,惠卫军,傅万堂等.中碳高强度弹簧钢NHS1超高周疲劳破坏行为[J].金属学报,2007,43(10)：1031-1036.
[17]张继明,杨振国,李守新等.汽车用高强度弹簧钢54SiCrV6和54SiCr6的超高周疲劳行为[J].金属学报,2006,42(3)：259-264.
[18]赵海民,惠卫军,聂义宏等.60Si2CrVA高强度弹簧钢的超高周疲劳破坏行为[J].材料研究学报,2008,22(5)：526-532.
[19]J. M. Zhang, S. X. Li, Z. G. Yang et al. Influence of inclusion size on fatigue behavior of high strength steels in the gigacycle fatigue regime[J]. International Journal of Fatigue, 2007,29:765-771.
[20]Duckworth W E. and Ineson E. Clean Steel 77(Iron Steel Inst.)1963.87.
[21]Kawada Y. and Kodama S. J. Japanese Soc. Strength Fract.Mater.1971,6(1):1.
[22]薛正良,李正邦,张家雯.不同生产工艺对高强度弹簧钢夹杂物尺寸分布及疲劳性能的影响[J].钢铁,2002,37(1)：22-25.
[23]周承恩,谢季佳,洪友士.超高周疲劳研究现状及展望[J].机械强度,2004,26(5)：526-533.
[24]申少华,刘国林,方克明等.硅酸盐夹杂对中板冷弯性能的影响[J].钢铁研究,2005(5)：45-47.
[25]朱红一,商存亮,刘微.中厚板冷弯裂纹分析[J].钢铁,2003,38(3)：47-49.
[26]李代钟.钢中硫化物夹杂物球化和对钢性能的影响[J].钢铁研究学报,1992,4(2)：97-101.
[27]上海交通大学编写组.金属断口分析[M].北京：国防工业出版社.1979.28.
[28]吴承建,陈国良,强文江.金属材料学[M].北京：冶金工业出版社.2006.8.
[29]闫桂玲,王弘,高庆.超声疲劳试验方法及其应用[J].力学与实践,2004,26：25-28.
[30]张继明,杨振国,张建峰等.零夹杂42CrMo高强度的超长寿命疲劳性能[J].金属学报,2005,41(2),145-149.
[31]鲁连涛,张卫华.金属材料超高周疲劳研究综述[J].机械强度,2005,27(3)：388-394.
[32]鲁连涛,李伟,张继旺等.GCr15钢旋转弯曲超长寿命疲劳性能分析[J].金属学报,2009,45(1)：73-78.
[33]杨振国,张继明,李守新等.42CrMoVNb细晶高强钢的疲劳行为[J].金属学报,2004,40(4)：367-372.
[34]Shiozawa K, Lu L T, Ishihara S. S-N Curve Characteristics and Subsurface Crack Initiation Behavior in Ultra Long Life Fatigue of A High Carbon-Chromium Bearing Steel [J]. Fatigue & Fracture of Engineering Materials & Structures,2001,24(12): 781-790.
[35]Murakami Y, Yokayama N, Nagata J. Mechanism of Fatigue Failure in Ultra long Life Regime[J]. Fatigue & Fracture of Engineering Materials & Structures,2002,25(8-9): 735-746.
[36]Murakami Y, Endo M. Int J Fatigue,1994,16:163.
[37]Murakami Y, Kodama S, Konuma S. Trans Jpn Soc Mech Eng,1988, A54:688.
[38]Murakami Y, Usuki H. Trans Jpn Soc Mech Eng,1989, A55:213.
[39]Murakami Y. Metal Fatigue:Effects of Small Defects and Nonmetallic Inclusions. Amsterdam:Elsevier,2002:91.
[2]董翰.合金钢的现状与未来.中国冶金,1996(6)：29.
[3]中国钢铁工业协会.2005年和2010年优型材需求预测.中国钢铁业,2004,(1)：31-35.
[4]弹簧行业“十五”发展规划.弹簧工程,2002,(72)：36.
[5]张世中.钢的过冷奥氏体转变曲线图集[M].冶金工业出版社,1982.
[6]林慧国,傅代直.钢的奥氏体转变曲线原理、测试与应用[M].机械工业出版社,1988.
[7]DIN50602-1985,特殊钢中非金属夹杂物评级[S].
[8]李代锺.钢中非金属夹杂物[M].北京：科学出版社.1983.56.
[9]惠卫军,董翰,曾新光等.超纯洁弹簧钢.钢铁,1999,34(9)：68-72.
[10]申少华,刘国林,韦弦等.中厚钢板中的硫化物夹杂及其对冷弯性能的影响[J].宽厚板,2005,11(2)：26-30.
[11]惠卫军,董瀚,陈四联.非金属夹杂物和表面状态对高强度弹簧钢疲劳性能的影响[J].特殊钢,1998,19(6)：8-14.
[12]张德堂.钢中非金属夹杂物鉴别[M].北京：国防工业出版社,1994．283.
[13]lankford J. International Metals Reviews,1997, (9):221.
[14]殷瑞钰主编.钢的质量现代进展(下篇·特殊钢)[M].北京：冶金工业出版社,1995.99.
[15]杨振国,张继明,李守新等.高周疲劳条件下高强度钢临界夹杂物尺寸估算[J].金属学报,2005,41(11)：1136-1142.
[16]聂义宏,惠卫军,傅万堂等.中碳高强度弹簧钢NHS1超高周疲劳破坏行为[J].金属学报,2007,43(10)：1031-1036.
[17]张继明,杨振国,李守新等.汽车用高强度弹簧钢54SiCrV6和54SiCr6的超高周疲劳行为[J].金属学报,2006,42(3)：259-264.
[18]赵海民,惠卫军,聂义宏等.60Si2CrVA高强度弹簧钢的超高周疲劳破坏行为[J].材料研究学报,2008,22(5)：526-532.
[19]J. M. Zhang, S. X. Li, Z. G. Yang et al. Influence of inclusion size on fatigue behavior of high strength steels in the gigacycle fatigue regime[J]. International Journal of Fatigue, 2007,29:765-771.
[20]Duckworth W E. and Ineson E. Clean Steel 77(Iron Steel Inst.)1963.87.
[21]Kawada Y. and Kodama S. J. Japanese Soc. Strength Fract.Mater.1971,6(1):1.
[22]薛正良,李正邦,张家雯.不同生产工艺对高强度弹簧钢夹杂物尺寸分布及疲劳性能的影响[J].钢铁,2002,37(1)：22-25.
[23]周承恩,谢季佳,洪友士.超高周疲劳研究现状及展望[J].机械强度,2004,26(5)：526-533.
[24]申少华,刘国林,方克明等.硅酸盐夹杂对中板冷弯性能的影响[J].钢铁研究,2005(5)：45-47.
[25]朱红一,商存亮,刘微.中厚板冷弯裂纹分析[J].钢铁,2003,38(3)：47-49.
[26]李代钟.钢中硫化物夹杂物球化和对钢性能的影响[J].钢铁研究学报,1992,4(2)：97-101.
[27]上海交通大学编写组.金属断口分析[M].北京：国防工业出版社.1979.28.
[28]吴承建,陈国良,强文江.金属材料学[M].北京：冶金工业出版社.2006.8.
[29]闫桂玲,王弘,高庆.超声疲劳试验方法及其应用[J].力学与实践,2004,26：25-28.
[30]张继明,杨振国,张建峰等.零夹杂42CrMo高强度的超长寿命疲劳性能[J].金属学报,2005,41(2),145-149.
[31]鲁连涛,张卫华.金属材料超高周疲劳研究综述[J].机械强度,2005,27(3)：388-394.
[32]鲁连涛,李伟,张继旺等.GCr15钢旋转弯曲超长寿命疲劳性能分析[J].金属学报,2009,45(1)：73-78.
[33]杨振国,张继明,李守新等.42CrMoVNb细晶高强钢的疲劳行为[J].金属学报,2004,40(4)：367-372.
[34]Shiozawa K, Lu L T, Ishihara S. S-N Curve Characteristics and Subsurface Crack Initiation Behavior in Ultra Long Life Fatigue of A High Carbon-Chromium Bearing Steel [J]. Fatigue & Fracture of Engineering Materials & Structures,2001,24(12): 781-790.
[35]Murakami Y, Yokayama N, Nagata J. Mechanism of Fatigue Failure in Ultra long Life Regime[J]. Fatigue & Fracture of Engineering Materials & Structures,2002,25(8-9): 735-746.
[36]Murakami Y, Endo M. Int J Fatigue,1994,16:163.
[37]Murakami Y, Kodama S, Konuma S. Trans Jpn Soc Mech Eng,1988, A54:688.
[38]Murakami Y, Usuki H. Trans Jpn Soc Mech Eng,1989, A55:213.
[39]Murakami Y. Metal Fatigue:Effects of Small Defects and Nonmetallic Inclusions. Amsterdam:Elsevier,2002:91.