| 摘要: |
| 低合金钢经高热输入的焊接之后,可能产生热影响区(HAZ)粗晶区韧性的严重下降。这与HAZ的组织转变有密切关系。本文采用光学金相、扫描电子显微镜和金属膜透射电子显微镜等方法,对正火状态14MnCuNiV钢的HAZ的显微组织和夹杂与韧性之间的关系进行了研究,主要结论如下:正火态的低合金钢经焊接热循环后,HAZ粗晶区韧性均有不同程度的下降,热输入增高,HAZ的脆性转变温度上升,韧性显著下降。当HAZ组织在具有足够冲击韧性的转变温度时,带状硫化物对冲击值起了显著的破坏作用。但在材料本身具有较大脆性而出现准解理形貌时,带状夹杂不再具有主导作用。金属薄膜透射电镜分析表明,高热输入HAZ的粒状贝氏体中存在挛晶马氏体的M-A组织。这类组织是高热输入脆化的主要原因.低热输入HAZ为板条马氏体+细粒状贝氏体组织,具有较好的低温韧性.本文利用HAZ的非平衡态冷却条WF粒状贝氏体形成过程的机理,来解释不同焊接热输入对HAZ粒贝小岛内M-A组织产生条件的影响.这一解释在薄膜透射电镜分析中得到了证实. |
| 关键词: |
| DOI： |
| 分类号: |
| 基金项目: |
|
| THE INFLUENCE OF MICRO-STRUCTURE AND INCLUSION ON TOUGHNESS OF HAZ OF LOW ALLOY STEEL WITH VARIOUS WELDING HEAT INPUT |
|
Ding Fubao, Ma Yujiang, Chen Yiqing
|
|
Shanghai Shipbuilding Technology Research
|
| Abstract: |
| The toughness of the HAZ coarse grained zone of low alloy steel might lose heavily with high welding heat input.This is closely related to the micro-structure transformation in HAZ.The present paper investigates the relation between the microstructure,inclusion and toughness by using optical microscope,scanning electron microscope and foil transmission electron microscope for examining normalized 14MnCuNiV steel. |
| Key words: |
