激光快速加热亚共析钢焊接热影响区的组织形态

Characterization of HAZ microstructure for hypoeutectoid steel undergone laser rapid heating

激光束和电子束焊按时,由于能量密度高、加热速度和冷却速度快,会在焊按热影响区看到普通弧焊时看不到的特殊的组织形态。通过光镜和电镜分析表明,由于加热速度快,相变温度以上的保温时间短,所以快速焊接亚共析钢时,会在热影响区得到比平均含碳量高的高碳马氏体和含碳量几乎为零的铁素体。

Special microstructures of HAZ for hypoeutcctoid steel, which could not be found in conventional are welding, were observed in laser welding and clectron beam welding because of the high energy densily and the rapid heating and cooling rate. OLM and TEM analyses showed that martensite with high carbon content and ferrite with practically no carbon were obtained.