A novel design scheme of hot stamping, quenching and partitioning process was conducted in a quenchable boron steel to obtain the nanometric duplex microstructure comprising ultrafine retained austenite and martensite...A novel design scheme of hot stamping, quenching and partitioning process was conducted in a quenchable boron steel to obtain the nanometric duplex microstructure comprising ultrafine retained austenite and martensite. It is shown that the materials possess excellent mechanical properties and the ductility can be further improved without compromising the strength. The newly treated steel shows excellent mechanical properties and the total elongation of the steel increases from 6.6% to 14.8% compared with that of hot stamped and quenched steel. Therefore, this kind of steel has become another group of advanced high-strength steels. The microstructure which is mainly responsible for such excellent mechanical properties was investigated.展开更多
A combined process of hot-deformation plus two-step quenching and partitioning （HDQP） treatment was applied to a low carbon 20Si2CrNi3MoV steel, and transmission electron microscopy （TEM）, scanning electron micros...A combined process of hot-deformation plus two-step quenching and partitioning （HDQP） treatment was applied to a low carbon 20Si2CrNi3MoV steel, and transmission electron microscopy （TEM）, scanning electron microscopy （SEM）, X-ray diffraction （XRD）, Vickers hardness and tension test were used to characterize the microstructure and mechanical properties. More stable retained austen ite due to fine microstructures and typical curved micromorphology is obtained, and the newly-treated steel obtains more retained austenite because of the effect of hot deformation. The retained austenite fraction increases and then decreases with the increasing quenching temperature from 200 to 350 ℃. The maximum retained austenite fraction （18.3 % ） and elongation （15 % ） are obtained to enhance the ductility.展开更多
研究了一次淬火马氏体对低合金钢经淬火和配分（Quenching and Partitioning，Q＆P）工艺后微观组织和单轴拉伸性能的影响，用扫描电镜进行微观组织表征，用X射线法测量残留奥氏体量。试验结果表明，随着一次淬火马氏体比例的增加，二...研究了一次淬火马氏体对低合金钢经淬火和配分（Quenching and Partitioning，Q＆P）工艺后微观组织和单轴拉伸性能的影响，用扫描电镜进行微观组织表征，用X射线法测量残留奥氏体量。试验结果表明，随着一次淬火马氏体比例的增加，二次淬火马氏体的尺寸和数量逐渐减少，残留奥氏体体积分数呈先增加后减少的趋势，一次淬火马氏体体积分数为40%时获得最大残留奥氏体体积分数为16.92%。一次淬火马氏体体积分数为30%～70%时试验钢获得了较高的塑性和强塑积，马氏体基体为钢提供了高强度，残留奥氏体在变形过程中的TRIP效应提高了钢的塑性。展开更多
基金Funded by the School Foundation of North University of Chinathe National Natural Science Foundation of China(Nos.51206081,51571141)+3 种基金Science and Technology Innovation Project of Shanxi Province(No.2016156)China Postdoctoral Science Foundation(No.2016M590214)Key Research and Development Program of Shanxi Province(No.201603D121002-3)the Natural Science Foundation of Shanxi Province,China(Nos.2015011036,2014011024-6)
文摘A novel design scheme of hot stamping, quenching and partitioning process was conducted in a quenchable boron steel to obtain the nanometric duplex microstructure comprising ultrafine retained austenite and martensite. It is shown that the materials possess excellent mechanical properties and the ductility can be further improved without compromising the strength. The newly treated steel shows excellent mechanical properties and the total elongation of the steel increases from 6.6% to 14.8% compared with that of hot stamped and quenched steel. Therefore, this kind of steel has become another group of advanced high-strength steels. The microstructure which is mainly responsible for such excellent mechanical properties was investigated.
基金supported by the National Key Research and Development Plan(Nos.2017YFB0304401 and 2016YFB0101605)the Major State Basic Research Development Program of China(973Program)(No.2010CB630803)
文摘A combined process of hot-deformation plus two-step quenching and partitioning （HDQP） treatment was applied to a low carbon 20Si2CrNi3MoV steel, and transmission electron microscopy （TEM）, scanning electron microscopy （SEM）, X-ray diffraction （XRD）, Vickers hardness and tension test were used to characterize the microstructure and mechanical properties. More stable retained austen ite due to fine microstructures and typical curved micromorphology is obtained, and the newly-treated steel obtains more retained austenite because of the effect of hot deformation. The retained austenite fraction increases and then decreases with the increasing quenching temperature from 200 to 350 ℃. The maximum retained austenite fraction （18.3 % ） and elongation （15 % ） are obtained to enhance the ductility.
文摘研究了一次淬火马氏体对低合金钢经淬火和配分（Quenching and Partitioning，Q＆P）工艺后微观组织和单轴拉伸性能的影响，用扫描电镜进行微观组织表征，用X射线法测量残留奥氏体量。试验结果表明，随着一次淬火马氏体比例的增加，二次淬火马氏体的尺寸和数量逐渐减少，残留奥氏体体积分数呈先增加后减少的趋势，一次淬火马氏体体积分数为40%时获得最大残留奥氏体体积分数为16.92%。一次淬火马氏体体积分数为30%～70%时试验钢获得了较高的塑性和强塑积，马氏体基体为钢提供了高强度，残留奥氏体在变形过程中的TRIP效应提高了钢的塑性。
