Cr含量对低合金耐蚀管线钢焊接接头组织和性能的影响

• 作 者: 胡丽华 张雷 许立宁 路民旭
• 机 构: 北京科技大学材料科学与工程学院,
• 出 处: 材料热处理学报
• 发表日期: 2010年03期
• 关键词: 焊接接头组织 Cr含量 管线钢 熔合区 粗晶区 焊缝组织 力学性能 淬硬组织 粒状贝氏体 热影响区

采用钨极氩孤弧焊(TIG)对Cr含量为1wt%～5wt%的低合金耐蚀管线钢进行焊接,研究Cr含量对焊接接头组织和力学性能的影响。结果表明,随着低合金耐蚀管线钢中Cr含量提高,粗晶热影响区晶粒尺寸变大,熔合区组织不均匀,易出现淬硬组织。随Cr含量提高,焊接接头的硬度呈上升趋势,冲击韧性呈下降趋势,尤其当Cr含量达5wt%时,硬度的提高和冲击韧性的下降尤为明显。低合金耐蚀管线钢的Cr含量不超过3wt%时,可得到硬度适中、韧性较高的焊接接头。

The low alloy corrosion resistant pipeline steel with Cr content of 1wt% ~ 5wt% was welded by TIG welding to study the effect of Cr content on microstructure and mechanical properties of welded joint. The results show that with the increase of Cr content in low alloy corrosion resistant pipeline steels, the grain size in the heat affected zone of coarse grains becomes larger and the microstructure of the fusion zone becomes inhomogeneous and the hardened structure tends to appear. With the increase of Cr content, the hardness of welded joint increases and the impact toughness decreases. Especially when the Cr content reaches 5wt%, the hardness and impact toughness decrease obviously. When the content of Cr in the low-alloy corrosion-resistant pipeline steel does not exceed 3 wt%, a welded joint with moderate hardness and high toughness can be obtained.