【摘要】：針對大型鍛件在生產(chǎn)過程中常因裂紋等孔隙性缺陷探傷超標(biāo)導(dǎo)致改鍛甚至判廢的問題,采用輻射加熱方式研究了低碳鋼內(nèi)部裂紋高溫修復(fù)及組織演變過程。結(jié)果表明:溫度為900℃時,裂紋附近富集析出鐵素體,裂紋修復(fù)以原子的擴(kuò)散遷移為主;1 000℃時,裂紋附近發(fā)生再結(jié)晶,裂紋間隙被大量細(xì)小的等軸鐵素體晶粒所填充,1 200℃時,等軸的鐵素體晶粒長大為鏈狀,并有晶�？邕^原裂紋區(qū)長大,形成共有晶粒;溫度高于1 000℃時,裂紋修復(fù)以再結(jié)晶和晶粒長大為主,再結(jié)晶的發(fā)生實現(xiàn)了裂紋的快速愈合。裂紋修復(fù)過程可分為4個階段:裂紋面局部凸起的形成與接觸,凸起的長大及裂紋的分段離散化,分段裂紋的球形化及孔洞的形成,孔洞的縮小及裂紋區(qū)的消失。該研究結(jié)果對揭示高溫裂紋修復(fù)機(jī)理和演化過程具有重要意義,為大型鍛件缺陷探傷標(biāo)準(zhǔn)的制定及質(zhì)量控制提供參考依據(jù)。
[Abstract]:In order to solve the problem that large forgings are modified or even scrapped due to pore defects such as cracks during production, the high temperature repair and microstructure evolution of internal cracks in low carbon steel are studied by means of radiation heating. The results show that when the temperature is 900 鈩，

本文編號：2146424