Subjects: Materials Science >> Materials Science (General) submitted time 2023-03-31 Cooperative journals: 《材料研究学报》
Abstract： Oxidation behavior of two ferrite/martensite(F/M) steels, namely a novel 9%-12% Cr modified F/M steel (SIMP steel) and a commercial T91 steel were comparatively studied in air at 800oC. The oxide scales formed on the two steels were characterized by XRD, SEM and EPMA. The results show that the oxide scale formed on SIMP steel is single-layer composed of Cr2O3 and Mn1.5Cr1.5O4 spinel particles, and Si was enriched at the interface between the chromia scale and matrix; while the oxide scale formed on T91 steel has a double layered structure with an outer hematite Fe2O3 layer and an inner Fe-Cr spinel layer. The SIMP steel has better high temperature oxidation resistance than T91 steel, which may be due to the higher content of Cr and Si beneficial to the formation of the compact oxide scale on the SIMP steel.
Subjects: Mechanics >> Applied Mechanics submitted time 2023-03-20 Cooperative journals: 《应用力学学报》
Abstract： Taking the saddle membrane structure as the research object , the vibration of the saddle mem-brane structure under the impact load is studied.First , the nonlinear differential equation of structural vi-bration under impact load is derived, in which the orthotropic of membrane material ,air damping , and geo-metric nonlinearity of membrane deformation are considered.'Then , it is assumed that a small ball impactsthe membrane surface with a certain impact velocity difference to simulate the impact load. Finally , the sto-chastic perturbation method is used to solve the equation , and the displacement function of the vibration re-sponse of the saddle membrane structure is obtained.At the same time, the vibration of the saddle mem-brane structure is numerically simulated and compared with the analytical theory.The results show that thevibration displacement of saddle membrane structure decreases with the increase of membrane pretension or arch span ratio, and increases with the increase of velocity difference. It can be seen that the theoreticalmodel is feasible in studying the vibration characteristics of saddle membrane structure under impact load,and the results can accurately predict the response law of membrane structure.
Subjects: Materials Science >> Materials Science (General) submitted time 2017-03-31 Cooperative journals: 《金属学报》
Abstract：为了评价反应堆候选结构材料与液态金属的相容性，本工作针对低活化马氏体钢在液态Pb-Bi共晶中的拉伸脆化现象，采用2种拉伸速率的拉伸实验，研究了中国低活化马氏体钢（CLAM）在200~500 oC范围内的Ar气和液态Pb-Bi共晶环境中的拉伸断裂行为。结果表明，在Ar气环境中拉伸时，CLAM钢均为韧性断裂；而在液态Pb-Bi共晶环境中拉伸时，在300~450 oC温度下会出现脆性断裂现象。在300~450 oC脆化温度区间内试样强度变化不大，但总延伸率显著降低，出现“韧谷”现象。然而拉伸温度在低于或高于脆化温度区间时，脆断现象消失，总延伸率回复到与对比试样相同水平。在更低的拉伸速率下， CLAM钢发生“韧谷”现象的温度区间明显扩大，表明拉伸速率对CLAM钢在液态Pb-Bi共晶中的脆化也有影响。经低温回火硬化后，CLAM钢在液态Pb-Bi共晶中出现拉伸脆化现象是由于液态Pb-Bi接触裂纹尖端后造成表面能降低，进而降低临界解理应力而发生脆性断裂。
Subjects: Materials Science >> Materials Science (General) submitted time 2016-11-15 Cooperative journals: 《金属学报》
Abstract：加速器驱动次临界ADS（Accelerator Driven Subcritical system）系统由加速器、散裂靶、反应堆三部分组成，被认为是安全处理核废料最具前景的技术方案。其中，散裂靶用结构材料需要同时具有耐高温、抗辐照、抗液态金属腐蚀等性能。针对这一挑战研发了新型核用马氏体耐热钢－SIMP钢。通过制衡9-12Cr%马氏体耐热钢中C、Cr、Si等重要元素含量对耐高温、抗辐照、抗液态金属腐蚀性能的影响，获得了SIMP钢优化的化学成分，极好地平衡了SIMP钢耐高温、抗辐照、抗液态金属腐蚀三方面性能。以1吨级和5吨级SIMP钢为实验材料的各项性能测试结果表明，SIMP钢是ADS系统中散裂靶的首选结构材料。
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