低碳低合金调质钢焊接HAZ组织遗传性及其对韧性的影响

STRUCTURAL HEREDITY IN WELD HAZ OF LOW-CARBON ALLOY Q AND T STEEL AND ITS EFFECT ON TOUGHNESS

摘要:

本文研究了HQ70低碳低合金调质钢模拟多次焊接热循环条件下,HAZ组织与性能的关系。发现,HQ70钢过热区粗大非平衡组织,经第二次快速加热到正火区,并没有出现通常所认为的"细化品粒"现象,而是出现了"组织遗传"。组织遗传区温度大约在750~1050℃。组织遗传现象的出现,使得HAZ脆化更加严重。本文对脆化原因进行了分析讨论,并就如何改善组织遗传对韧性的影响进行了探讨。

Abstract:

The relationship between HAZ structure and properties of HQ70 low-carbon low-alloy Q and T steel under multiple weld thermal cycle simulating conditions was studied.It was discovered that structural heredity phenomenon took place in the non-equilibrium structure of overheated zone of HQ70 steel after another quick heating.The temperature range of structural heredity was found to be approximately 750~1050℃.Stuctural heredity worsened the embrittlement of HAZ overheated zone.The causes of embrittlement were analyzed and discussed,and the measures for improving the effect of structural heredity on toughness studied.