论文部分内容阅读
用Gleeble-3800热模拟机对Ni-Cr-Mo-B低合金高强度钢进行不同焊接热输入条件的下热模拟试验,研究了模拟焊接热影响区的组织和性能,探讨了不同热输入条件(对应不同的t8/5)对钢中微观组织及形态的影响以及组织与低温韧性的关系。结果表明:随着热输入能量的增加,此类钢焊接热影响区的低温韧性呈现先增后降的规律。当以中等焊接热输入施焊,在热影响区形成贝氏体/马氏体复相组织,先形成的贝氏体对原始奥氏体晶粒的分割作用,使后生成的板条马氏体具有更细的板条束,从而获得最佳的低温韧性。而低热输入时形成全马氏体组织,高热输入时获得一定量的粒状贝氏体,两种组织的低温韧性均低于贝氏体/马氏体的复相组织。
The heat simulation experiment of Ni-Cr-Mo-B low-alloy high-strength steel under different welding heat input conditions was carried out by Gleeble-3800 thermal simulator. The microstructure and properties of simulated heat-affected zone were studied. The effects of heat input conditions (Corresponding to different t8 / 5) on the microstructure and morphology of steel and the relationship between the organization and low temperature toughness. The results show that with the increase of heat input energy, the low temperature toughness of HAZ of this kind of steel first increases and then decreases. When welded with medium welding heat input, the bainite / martensite duplex structure is formed in the HAZ. The first formed bainite can separate the original austenite grains, and the resulting slab Ma The body has thinner battens for optimal low temperature toughness. The formation of low-heat input all-martensite, high heat input to obtain a certain amount of granular bainite, the two organizations are lower than the low-temperature toughness bainite / martensite complex phase organization.