为提高低合金高强铸钢（ HSLA）的综合力学性能，满足恶劣环境下的使用要求。采用光学显微镜、扫描电镜、透射电镜、冲击试验机、万能材料试验机研究了3种不同冷速及高温回火对HSLA铸钢组织与力学性能的影响。结果表明：随冷速增加，淬火组织发生由多边形铁素体＋针状铁素体＋粒状贝氏体→粒状贝氏体＋板条贝氏体→准上贝氏体＋板条马氏体的演变。冷速为1℃/s的空冷样，具有最高的塑韧性；冷速最大的水冷样，其强度、硬度最高。冷却样经580℃回火，其晶界、板条界均有粒状、短棒状的纳米第二相析出，EDS分析表明，100～200 nm的析出相为合金渗碳体（ M3 C），而50 nm以内的析出相为（ V，Ti）（ C，N）。空冷样回火后有较高强度、最高的塑韧性；油冷、水冷样回火后，Re提高，Rm略有下降，AkU降低与高温回火脆性的发生有关，但-40℃的AkU仍有60、40 J，具有较好的低温冲击韧性。可见，试验HSLA铸钢表现出良好的综合力学性能，能满足在恶劣环境下的使用要求。
To improve comprehensive mechanical properties of high strength low alloy(HSLA) cast steel, and meet application requirements of HSLA cast steel in harsh environments, the mechanical properties and microstructures of HSLA cast steel cooled at three different cooling rates and subsequently tempered at 580℃ were studied by optical microscope, scanning electron microscopy, transmission electron microscopy, impact tester and universal material test. With the cooling rate increasing, the microstructure evolved from ferrite + granular bainite, lath bainite, to lath martensite + quasi upper bainite. Higher plasticity and toughness were obtained at a slower cooling rate of 1℃/s. Water cooled sample had maximum strength and hardness, at the expensive of impact energy slightly. Nano-precipitates of granular, short rod were found along grain, lath boundary in cooled samples after tempering. EDS analysis revealed that the precipitates of 100~200 nm were M3 C, and that within 50 nm in size were ( V, Ti ) (C,N). The maximum plasticity and toughness(elongation rate A=27% impact energy, Charpy U-notch impact energy AkU=113 J at -40℃) were achieved by air cooled sample after tempering. The yield strength of specimen after cooling and tempering increased, the occurrence of high temperature temper brittleness led to reduction of impact toughness, whereas impact energy was remained 60 J, 40 J at -40℃, respectively.
参考文献
| [1] | JANABD,CHAKRABARTIAK,RAYKK .Studyof cast micro-alloyed steels[J].Materials Science and Technology,2003,19(1):80-86.,2003. |
| [2] | NAJAFIAH,RASSIZADEHGHANIJ,ASGARIS .As-cast mechanical properties of vanadium/niobium mi-croalloyed steels[J].Materials Science and Engineer-ing A,2008,486:1-7.,2008. |
| [3] | BANGARU,RAOVN.HighperfoRmancehighstrength low alloy cast steels [P]. United States Patent:5129966. 1992-07-14.,1992. |
| [4] | LUOKaishuang,BAIBingzhe .Microstructureandme-chanical properties of a low alloyed MnB cast steel[J].Journal of Materials Engineering and PerfoRmance,2010,19(6):828-833.,2010. |
| [5] | 耿浩然,章希胜,陈俊华,等.铸钢[M].北京:化学工业出版社,2007:1-286.,2007. |
| [6] | ÇALIKA .Effectofcoolingrateonhardnessandmicro-structure of AISI1020, AISI1040 and AISI1060 steels[J].InternationalJournal of Physical Sciences,2009,4(9):514-518.,2009. |
| [7] | DASS,GHOSHA,CHATTERJEES,etal .Theeffect of cooling rate on structure and properties of a HSLA forging[J].Scripta Materialia,2003,48(1):51-57.,2003. |
| [8] | GHOSHA,DASS.Effectofcoolingrateonstructure and properties of an ultra-low carbon HSLA-100 grade steel [J]. Materials Characterization, 2006, 56 (1):59-65.,2006. |
| [9] | DHUASK,MUKERJEED,SARmADS.Effectof cooling rate on the as-quenched microstructure and me-chanical properties of HSLA-100 steel plates[J].Met-allurgical and Materials Transactions A, 2003, 34 (11):2493-2504.,2003. |
| [10] | QIAO Z X,LIU Y C,YU L M,et al.Effect of cooling rate on microstructural foRmation and hardness of 30CrNi3Mo steel [J]. Applied Physics A, 2009, 95 (3):917-922.,2009. |
| [11] | 匡加才,符寒光,王林涛.碳含量对Si-Mn-B铸钢显微组织和抗磨性的影响[J].材料热处理学报,2007(06):78-81. |
| [12] | 高宽,王六定,朱明,陈景东,施易军,康沫狂.低合金超高强度贝氏体钢的晶粒细化与韧性提高[J].金属学报,2007(03):315-320. |
| [13] | 于庆波,孙莹,倪宏昕,张凯锋.不同类型的贝氏体组织对低碳钢力学性能的影响[J].机械工程学报,2009(12):284-288. |
| [14] | 徐洲,姚寿山.材料加工原理[M].北京:科学出版社,2002:1-396.,2002. |
| [15] | 惠卫军,董瀚,翁宇庆.42CrMoVNb细晶高强度钢的力学行为[J].材料热处理学报,2005(05):57-61. |
| [16] | GŁOWNIA J, KALANDYK B . Effect of precipitation strengthening in low alloyed Mn-Ni cast steels[J].Journal of Materials Processing Technology,2008,207:147-153.,2008. |
| [17] | 许峰云,白秉哲,方鸿生.低碳Mn系水淬贝氏体钢的组织和力学性能[J].材料热处理学报,2010(09):83-88. |
| [18] | 张永权,张荣久,苏航,李丽.粒状贝氏体对10MnNiCr微合金钢力学性能的影响[J].钢铁,2003(11):45-47,39. |
| [19] | 王立军,蔡庆伍,武会宾,余伟.回火温度对1500MPa级直接淬火钢组织与性能的影响[J].北京科技大学学报,2010(09):1150-1156,1162. |
| [20] | 王立军,蔡庆伍,余伟,武会宾,雷爱娣.低碳低合金钢的连续冷却相变组织特征及其形成机制[J].材料工程,2010(08):29-33. |
| [21] | 武会宾,尚成嘉,苑少强,杨善武,王学敏,贺信莱.超细化低碳贝氏体钢的回火组织稳定性及力学性能[J].材料热处理学报,2004(06):65-70. |
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