摘要
本文通过WX52管线钢及其焊接接头的Charpy V型缺口(CVN)试样和预制裂纹的Charpy V型缺口(PCVN)试样的示波冲击试验,研究了载荷—挠度曲线上最大载荷前的能量Ei的物理意义及其影响因素。结果表明:CVN试样的Ei代表实际的裂纹萌生功,而PCVN试样的Ei为裂纹萌生功Eic与部分裂纹扩展功Ei_3之和.无论材料均匀与否,Ei值均随温度降低而减小。CVN试样Ei—T曲线上有3个特征温度:①Tb——低于该温度,裂纹解理起裂;②Td——高于该温度,裂纹延性起裂;③Tr——中间平台区的上限温度。可是PCVN试样的Ei—T曲线上仅有Tb及Td两个特征温度,裂纹萌生功受试样取向,焊缝化学成分及裂纹尖端应变集中程度所影响。
Instrumented impact test was carried out on a WX52 steel and its welded joint by using the Charpy V-notch (GVN) specimen and precracked Charpy V-notch (PCVN) specimen.The physical meaning of energy absorbed up to the maximum load in the load-deflection curve, Ei, and several factors affecting the Ei value were studied. It was found that for the CVN specimen the Ei value expressed the crack initiation energy, while for the PCVN specimen the Ei value was the sum of crack initiation energy and part of energy of crack propagation. The Ei value decreased with the test temperature no matter the material was homogeneous or heterogeneous. For the CVN specimen, therewere th■ee characteristic temperatures in the Ei-T(℃) relation curve:(l)Tb——cleavage crack initiation would occur when the temperature was lower than Tb;(2) Td——ductile crack initiated when the temperature was higher than Td;(3) Tr——the upper limit of temperature of the middle shelf in the Ei-T(℃) relation curve. Howcver, there were only two characteristic temperatures, Tb and Td, for PCVN specimen. The Ei value was affected by specimen orientation, chemical composition of weld metal, and strain concentration.
出处
《焊接学报》
EI
CAS
CSCD
北大核心
1989年第3期172-180,共9页
Transactions of The China Welding Institution
