汽车钢淬透性数学模型建立

在测定 2 0CrMnTi、4 0MnBH、2 0MnVBH钢淬透性及试样的化学成分基础之上 ,利用计算机采用逐步回归分析方法进行了回归运算 ,得到淬透性与化学成分的关系———回归方程 ,根据回归方程求出了不同窄淬透带规格所对应控制的化学成分范围     

20MnVBH钢的奥氏体晶粒度及淬透性研究

研究了用电弧炉，平炉和非真空感应炉冶炼的２０ＭｎＶＢＨ钢的奥氏体晶粒度及淬透性。结果表明，有效钛是决定钢奥氏体晶粒度的主要参数；有效硼是决定该钢淬透性的主要参数。     

拉伸变形对AA6016铝合金汽车外板再结晶组织及性能的影响

为优化冲压成形工艺,研究了不同拉伸形变量对T4P态AA6016冷轧薄板再结晶、析出行为、烘烤硬化性及断裂方式的影响规律.采用与气垫炉生产线类似的新型热处理设备,对合金进行固溶处理,预时效后室温停放,获得T4P态合金.以单向拉伸模拟板材局部冲压成形过程,采用金相显微镜、扫描电镜和透射电镜,对合金再结晶组织、拉伸断口以及位错进行观察,并结合DSC测定和拉伸性能测定,对合金析出行为及力学性能表征.结果表明:随拉伸形变量增加,局部晶粒有被拉长的趋势;形变可抑制GP区溶解,并促进强化相析出;烘烤硬化性随形变增加而减弱;形变较小时,烘烤前后断裂方式均为塑性断裂,而形变较大时,烘烤前合金更加趋向于解理断裂,烘烤后解理断裂趋势减弱.     

Effects of different tempers on precipitation hardening of 6000 series aluminium alloys

By means of Vickers hardness,mechanical property and formability tests,the effects of different tempers on precipitation hardening of 6000 series aluminium alloys for automotive body sheets were investigated.The results indicate that the short-time pre-aging at 170℃makes for subsequent artificial aging precipitation hardening.With the increase of pre-aging time,the artificial aging hardenability increases.The aging hardening rate reaches the maximum when pre-aging time is up to 10 min,and then it decreases.The short-time pre-aging at 170℃benefits sheets to obtain lower strength under delivery condition and consequently to improve stamping formability of automotive body sheets.The effects of different tempers on precipitation hardening are much more obvious than those of the alloying elements.It is a good treatment schedule to perform pre-aging for 5 min at 170℃right after solution treatment.     

40Cr钢的淬透性研究

在研究不同奥氏体化温度下４０Ｃｒ钢的淬透性时，发现其淬透性曲线上硬度不是单调下降，而出现了一硬化峰，该峰值硬度为３２±２ＨＲＣ，峰位距端面的距离随淬火温度提高而后移，与奥氏体化温度无关．ＴＥＭ等分析表明，峰值出现的原因是在特定的冷速条件下，铬的碳化物析出强化了珠光体以及Ｆｅ４Ｎ型有序相形成强化了铁素体而引起的．硬度峰出现的冷速为２～４℃／Ｓ。     

Prediction of jominy hardness profiles of steels using artificial neural networks

Jominy hardness profiles of steels were predicted from chemical composition and austenitizing temperature using an artificial neural network. The neural network was trained using some 4000 examples, covering a wide range of steel compositions. The performance of the neural network is examined as a function of the network architecture, the number of alloying elements, and the number of data sets used for training. A well-trained network predicts the Jominy hardness profile with an average error of about 2 HRC. Special attention was devoted to the effect of boron on hardenability. A network trained using data only from boron steels produced results similar to those of a network trained using all data available. The accuracy of the predictions of the model is compared with that of an analytical model for hardenability and with that of a partial least- squares model using the same set of data.     

钛对20CrMnTi钢淬透性影响的研究

本文设计了一系列工艺试验,研究了钛及热处理工艺对20CrMnTi钢淬透性的影响。结果表明,钛在20CrMnTi中最适合的含量在0.07％左右,它既保证了奥氏体晶粒度,又提高了钢的淬透性;同时还分析了影响该钢淬透性的因素,认为TiC的析出行为是首要因素之一。     

合理制订渗碳淬火工艺的计算方法

零件通过渗碳淬火工艺获得的有效硬化层深度,受到许多因素的影响。本文阐述和计算零件的材料成分、奥氏体晶粒度、零件质量效果、淬火冷却烈度、各合金元素的淬透性特性值、碳热、淬火加热温度等的影响,并根据计算值同实验值的比较进行适当的修正,制定出合理的渗碳淬火工艺。     

矩形坯连铸生产40MnB钢试验研究

借鉴国内钢厂生产40MnB钢的成功经验，设计出首钢连铸生产40MnB钢的内控成分和各工序关键工艺，利用BOF-LF—CC工艺批量生产汽车用优质钢40MnB。     

用修正淬透性系数法对反应堆压力容器锻件RTNDT数值的预估

分析反应堆压力容器（RPV）锻件制造过程中关键化学元素含量及基准无塑性转变温度（RTNDT）数值，通过引入修正淬透性系数，建立了反映RTNDT变化规律的修正淬透性系数函数表达式，并给出了实例验证，结果表明，通过本文建立的修正淬透性系数函数式可以比较精确地预估RPV锻件的RTNDT值。