合金结构钢10CrNi3MoV探伤不合原因分析

Cause Analysis on Non-conformity of Alloy Structural Steel 10CrNi3MoVby Flaw Detection

对14 mm和28 mm 10CrNi3MoV钢板非夹杂元素超标导致的探伤不合格的原因进行了分析,通过采用扫描电镜和光学显微镜对探伤不合处的显微组织和微区成分进行分析。结果表明,试验钢10CrNi3MoV探伤不合的原因是内部存在裂纹。裂纹产生的原因是钢板存在较大的偏析和组织应力,裂纹发生在贝氏体或贝氏体与珠光体交界区域。裂纹发生处溶质原子Ni、Cr、Mn发生明显聚集。Ni、Mn元素的偏析,导致形成贝氏体、珠光体和铁素体偏析条带,造成组织内应力。溶质原子在距钢板表面约1/4处聚集由电磁搅拌和动态轻压下引起,为了消除此类现象,应降低电磁搅拌的功率,选择适当的过热度。

In this paper,the causes of unqualified flaw detection of 14mm and 28mm 10CrNi3MoV steel plates caused by noninclusion elements exceeding the standard are studied.Through the analysis of the microstructure and micro area composition of the flaw detection joints by using scanning electron microscope and optical microscope,the results show that the reason for unqualified flaw detection of test steel 10CrNi3MoV is that there are cracks inside.The reason for the crack is that the steel plate has large segregation and structural stress,and the crack occurs in the bainite or the boundary area between bainite and pearlite.The solute atoms Ni,Cr and Mn obviously aggregate at the crack location.The segregation of Ni and Mn elements leads to the formation of bainite,pearlite and ferrite segregation bands,resulting in internal stress in the structure.The concentration of solute atoms at about 1/4 of the steel plate surface is caused by electromagnetic stirring and dynamic soft reduction.In order to eliminate this phenomenon,the power of electromagnetic stirring should be reduced and proper superheat should be selected.