共查询到18条相似文献,搜索用时 62 毫秒
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通过在Gleeble-3500热/力模拟实验机上的热压缩实验,本文研究了在不同热变形条件下X120管线钢的高温变形抗力,分析了变形程度、变形温度及变形速率与变形抗力之间的关系,最终建立了X120管线钢的热轧变形抗力数学模型,并通过回归分析验证了此模型具有较高的拟合精度。 相似文献
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Deng Wei Gao Xiuhua Qin Xiaomei Zhao Dewen Du Linxiu State Key Laboratory of Rolling Automation Northeastern University Shenyang China 《稀有金属材料与工程》2011,(Z3):123-127
Single welding thermal–cycles with different input linear energies (ILE)(15, 20, 30, 40, 50 kJ/cm) and peak temperatures (PT) (900, 1050, 1200, 1300, 1350 ℃) were simulated by MMS-300 to study the correlation of toughness and microstructure in heat-affected zone (HAZ) of a X80 pipeline. The evolution characteristics of microstructure were investigated by OM, SEM and EBSD. The results show that numerous polygonal ferrites and grain boundary ferrites appear, and the sizes apparently decrease as the heat input decreases. Heat input in single welding should be less than 35 kJ/cm to ensure well Charpy impact toughness. The toughness of course grain zone is the lowest when welding heating temperature is 1350 ℃ and it is the weakness part in welded zone. The uniformity of prior austenite grain is worsened as increasing the heat input. Moreover, the characteristics of M-A constituents and high angle grain boundaries (HAGB) are influenced by heat input and PT. In the case of low heat input and PT, higher density of HAGBs, dispersed and fine M-A constituents were observed. Otherwise, with high heat input (≥40 kJ/cm), the effective grain size is almost the diameter of prior austenite grain, and it will decrease the density of HAGB, moreover, coarse M-A constituents which are prone to crack initiation will be generated, thus, the impact toughness of the coarse grain zone will be worsened obviously in welding HAZ. 相似文献
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利用热模拟技术研究了焊接热循环对高强钢S690QL焊接热影响区的组织和韧性的影响,重点分析了一次及二次热循环下淬火粗晶区(CGHAZ)组织转变与韧性的关系.结果表明,一次热循环下CGHAZ韧性严重恶化,其值接近S690QL韧性指标下限值,该区随t8/5不同所形成的粗大板条马氏体、富碳淬硬相及上贝氏体组织是致使低温韧性恶化的主导因素,而CGHAZ区段内原奥氏体晶粒大小随峰值温度的梯度变化对该区韧性影响程度较小,不同峰值温度下的二次热循环对原一次CGHAZ的组织及碳化物析出形态有所改变,进而对韧性影响不一. 相似文献
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X120级管线钢DQ-T工艺试验研究 总被引:4,自引:1,他引:3
通过合理的组织、成分设计,采用直接淬火回火(DQ-T)工艺,在实验室成功试制X120级管线钢,并结合金相、透射电子显微技术,研究了不同回火温度对试验钢组织、析出与性能的影响规律.结果表明,随回火温度的升高,屈服强度Rel呈现起伏现象,在450 ℃和650 ℃回火后出现两次峰值,抗拉强度Rm变化趋势与Rel相似,起伏相对平缓;冲击功AKv(-20 ℃)、伸长率A均有一定波动,在450 ℃回火后,AKv(-20 ℃)>230 J,A>15%.淬火后450 ℃回火,钢板为下贝氏体与回火马氏体组织,具有最优的综合力学性能,Rel=845 MPa,Rm=940 MPa,A=16.5%,AKv(-20 ℃)=236 J,各项指标均符合X120管线钢性能要求. 相似文献
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