共查询到19条相似文献,搜索用时 156 毫秒
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钒微合金化在热轧带肋钢筋中的强化机理研究 总被引:2,自引:0,他引:2
利用钒氮合金和钒铁合金进行合金化,并研究了钒对热轧带肋钢筋(0.21%~0.23%C、1.33%~1.50%Mn)组织和性能的作用机理。结果表明,采用钒铁合金化、钒氮合金化方法,使含0.06%钒钢筋分别达到HRB400级、HRB500级钢筋的力学性能要求;同样钒含量,钒氮合金化的钢筋中析出比例比钒铁合金化高83%~110%,钒氮合金化的钢筋沉淀强化作用比钒铁合金化更强,析出物以V(CN)为主,VC析出量少。钒氮合金化能使钢的室温组织更细小,但游离氮较多,时效现象将更加显著。 相似文献
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采用金相显微镜和拉伸试验研究了钒对高氮钢筋组织与力学性能的影响。结果表明:随着钒含量的增加,钢筋的屈服强度增加,钒在钢筋中的强化机制为细晶强化和沉淀强化,其中沉淀强化是钒微合金化钢筋的主要强化方式。 相似文献
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对比了宣钢采用单纯的钒氮合金和微氮合金+钒氮合金两种微合金化工艺生产的HRB400E、HRB500E抗震钢筋中钒微合金化效果。分析结果表明,单纯采用钒氮合金微合金化生产的HRB400E钢筋中未发现有VN析出相的证据,HRB500E钢筋的VN析出效果很明显,但未发现有V(CN)析出相的证据;采用微氮合金+钒氮合金微合金化生产的,HRB400E钢筋中具有VN析出相,HRB500E钢筋中有V(CN)析出证据,且析出效果很明显。 相似文献
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针对近期生产的一批屈服强度偏低的HRB500E抗震钢筋样品进行了化学成分、金相组织、氧氮含量等分析,结果表明:屈服强度低的钢筋组织为正常的铁素体+珠光体,钢中的C,Si,Mn,V等合金强化元素含量正常,但钢中N的体积分数仅有(66~94)×10-6,屈服强度性能合格的样品中N的体积分数达到130×10-6,HRB500E使用VN微合金强化,只有当钢中N含量达到一定程度(钒氮比为3.64:1),V的析出强化才能达到最佳效果.通过改进VN微合金化方式,使用钒氮合金进行VN微合金化,有效提高和稳定了钢中的氮含量,提高了钢筋的屈服强度. 相似文献
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介绍济钢采用钒氮合金微合金化工艺生产HRB400钢筋的情况。研究了钒氮微合金化对钢筋组织、性能的影响,分析了钒氮微合金化的化学成分与力学性能的关系。研究结果表明,使用钒氮合金生产HRB400钢筋的工艺是可行的。 相似文献
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Worldwideattentionhasbeenpaidtomicroal loyedsteelwhichhasbeendevelopedrapidly .Manyadvantagesofmicroalloyedsteelhavebeenrecog nizeddeeply .Firstly ,themicroalloyedsteelhashighstrengthand goodcomprehensiveproperties .Sec ondly ,highprofitscanbegainedduetolowerpro ductionandapplicationcost .Themicroalloyingele mentsareaddedtomicroalloysteelsforgrainrefin ingandprecipitationstrengthening[1] . Theabilityofsecondphaseparticlestomaintainfinegrainsizesathightemperaturebypinningmi gratingboundarie… 相似文献
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氮在非调质钢中的作用 总被引:10,自引:1,他引:9
了氮在非调质钢中所起的有益作用。在Nb,V,Ti三咱微合金化元素中,钒有较高的溶解度,钒有较高的溶解度,是非调质钢最常用也是最有效的强化元素。钒在钢中通过形成细小析出相起细化晶粒和沉淀强化作用。与碳相比,氮与钒有更强的亲和力,且氮化物更稳定,因此,氮对控制钒的析出起更重要的作用。大量研究结果表明,非调质钢中增氮改变了钒在相间的分布,促进V(C,N)析出,使析出相的颗粒尺寸明显减小。因而氮增强了非调 相似文献
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Precipitation Behavior of VN in High Nitrogen and Vanadium Micro-alloyed Low Carbon Weathering Steel
Bo Wang Zhu-tie Li Dong-ping Zhan Mao-fa Jiang 《Transactions of the Indian Institute of Metals》2018,71(7):1607-1613
In this study, the high nitrogen and vanadium micro-alloyed low carbon weathering steel (0.0320%N–0.096V) with excellent mechanical properties was produced. TEM and EDS tests of the hot rolled specimens were conducted and it was found that a great number of VN precipitates were generated and the size of VN particles was in the range of 10–300 nm, which exceeded the critical size of 7.89 nm for pinning dislocation line. Thermodynamic calculation results showed that, at high temperature, the precipitation performance of VN remarkably increased due to high nitrogen content. For the experimental steel, the initial precipitation temperature of VN reached 1133 °C and the precipitation rate of V exceeded 90% at the finish rolling temperature of 850 °C. The precipitation temperature time (PTT) curves drawn from kinetic data showed that the fastest precipitation temperature was about 950 °C. The total precipitation time was shortened from 110 to 10 s at 850 °C due to the high dislocation density caused by deformation, and the VN particles could thus be completely precipitated with a brief relaxation process. High nitrogen and vanadium micro-alloying was beneficial for improving the grain refinement and precipitation strengthening effect of vanadium. 相似文献
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新标准实施后,为了探究热轧带肋钢筋最佳生产工艺,对广东省不同生产工艺的主要钢企生产的钢筋进行了研究。分析表明,采用穿水冷却工艺,试样的强度偏高、韧性偏低,金相组织不合格,部分试样反向弯曲及抗震性能不合格,说明该工艺已严重不符合新标准要求;采用加铬、钼合金化热轧工艺,试样间强度偏差较大,且反向弯曲性能不合格,说明工艺不易控制、产品质量不稳定;采用常规热轧工艺,试样屈服强度偏低,仅高出标准下限1~2 MPa,说明该工艺生产的钢筋强度不够;采用钒氮合金化热轧工艺,试样各项试验指标均良好,当钒质量分数为0.33%~0.36%、氮质量分数为0.022%~0.025%时,产品综合质量最佳。 相似文献
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摘 要: 为了分析大线能量焊接下接头低温韧性的影响因素,研究轧制工艺对V-N-Ti钢粗晶热影响区(CGHAZ)组织和韧性的影响。试验结果表明,当终轧温度从950降低到800 ℃,且t8/5(从800冷却到500 ℃的时间)为180 s时,CGHAZ中铁素体面积百分数从91.2%降低到53.9%,贝氏体面积百分数从0%增加到31.1%,-20 ℃冲击功从182降低到92 J。上述现象是由于终轧温度影响了母材中尺寸为30~70 nm的富Ti-(Ti,V)(C,N)粒子的成分。与低温终轧相比,高终轧温度条件下母材中富Ti-(Ti,V)(C,N)粒子的V元素含量较高,这使其在焊接加热过程中更易发生溶解,并在焊接冷却过程中以细小富Ti-(Ti,V)(C,N)析出,钉扎奥氏体晶界;焊接冷却过程中,富Ti-(Ti,V)(C,N)可以作为V元素的析出核心促进VN的析出,提高了其铁素体形核能力,改善了CGHAZ组织和韧性。 相似文献
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The strain aging characteristics of reinforcing steel with a range of vanadium contents 总被引:3,自引:0,他引:3
The strain aging characteristics of a reinforcing steel made with vanadium ranging between zero and 0.1 pct and with two aluminum
levels have been investigated for the ashot rolled condition. It has been shown that vanadium contents of 0.04 to 0.06 pct
(a V/N ratio of 7 to 9) will result in the combination of almost all the active nitrogen as vanadium nitride and suppresses
natural strain aging. Vanadium in excess of this level results in the precipitation of vanadium carbide and the consequential
precipitation hardening gives an increase in the yield strength, tensile strength, and impact transition temperature without
imparting further beneficial effect with regard to strain aging. The mechanical properties have been shown to be generally
unaffected by the two different aluminum levels, and no grain refinement resulted from either the vanadium or aluminum additions.
This absence of grain refinement and the precipitation hardening results in an increase in the impact transition temperature
with increasing vanadium content, although this increase is initially slow whilst the active nitrogen content is being reduced. 相似文献