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某钢铁公司生产的一种低碳贝氏体钢,由于生产工艺条件限制未经回火,强度极不稳定.通过对该钢进行金相检测、力学性能检测、断口宏观检测、扫描电镜检测、能谱分析后表明,韧窝尺寸、微观组织、夹杂物都与强度有一定关系.韧窝尺寸大且较深时,屈服强度较高；板条贝氏体所占比例大,马奥岛弥散细小,强度相对较高；大尺寸的夹杂物,尤其是铝、钙的氧化物及硫化物,是薄弱环节,容易导致断裂.

Strength Analysis of Low-Carbon Bainitic Steel

The strength of low-carbon bainitic steel made by a steel company was instability because it was not tempered for a limited production condition.After the analysis of metallographic examination,mechanical properties,macroscopic examination,SEM and energy spectrum,it showed that the strength was related to dimple size,microstructure and inclusions.Higher yield strength can be obtained when the dimple was large and deep;the strength is higher with lathy bainitic of large scale and smaller MA island;large size inclusions,especially oxides and sulfides containing Al and Ca is the weak leak and easy to break.