%0 Journal Article
%T STRESS-STRAIN BEHAVIORS AROUND THE YIELD STRENGTH IN SEQUENTIAL ROOM TEMPERATURE CREEP TESTS<br>相续室温蠕变中屈服强度附近的应力应变行为
%A NIE Defu
%A ZHAO Jie
%A <br>聂德福
%A 赵杰
%J 金属学报
%D 2009
%I 
%X The deformation of metallic materials at low homologous temperature (the ratio of experimental temperature and melting point T/Tm<0.2) used to be described by time independent models. With the development of measuring technique and the improvement of required accuracy, the time dependence of deformation has been concerned about. So far, room temperature creep (RTC) has been observed in many metals and alloys, and some experiments have been performed to investigate the fundamental deformation mechanism and influencing factors. A previous paper reported that RTC increased the subsequent flow stress of an X70 pipeline steel. However, the evolution of deformation following RTC is not thoroughly understood. In this paper, sequential RTC tests and their effects on the subsequent deformation have been investigated in the X70 pipeline steel. The steel exhibits time dependent deformation at various stress levels around yield strength, and RTC is generally primary α type. Moreover, the post--yield RTC markedly enhances the subsequent flow stress. The influence of RTC on subsequence stress--strain behavior can be evaluated using strain rate--stress curve: the burst point of strain rate, due to pre--yield RTC process, is lower than elastic limit, while a distinct peak is observed after RTC has been performed at higher stress level. Local mobile dislocation model has been applied to analyze the behavior.
%K room temperature creep
%K yield strength
%K X70 pipeline steel
%K strain rate<br>室温蠕变
%K 屈服强度
%K X70管线钢
%K 应变速率
%U http://www.alljournals.cn/get_abstract_url.aspx?pcid=5B3AB970F71A803DEACDC0559115BFCF0A068CD97DD29835&cid=AB188D3B70B071C57EB64E395D864ECE&jid=B061E1135F1CBDEE96CD96C109FEAD65&aid=8156C5FAB18A55B890E69EFEB1C2C9D4&yid=DE12191FBD62783C&vid=94E7F66E6C42FA23&iid=DF92D298D3FF1E6E&sid=F7B726EE3ACCF328&eid=85C7135C065B9251&journal_id=0412-1961&journal_name=金属学报&referenced_num=0&reference_num=9