摘要
针对PSB830精轧螺纹钢筋延伸率低的试样,进行化学成分、断口形貌、夹杂物级别、组织特征等检测后发现,淬硬层厚、淬火组织自回火不充分是钢筋生产检验延伸率不合格的主要原因。回火工艺实验表明:450℃~500℃+90min回火处理,马氏体充分分解转变,钢筋塑性大幅度提高,各项性能指标满足标准要求。经450℃+90min工业回火工艺处理,可成功挽救不合格钢筋,减少企业损失。
Against for the PSB830 finishing rolling reinforced bar of the low fracture extensibility specimen, the testings of chemical composition, inclusiongrade, microstructure and fracture were carried out, then it was found that the hardened layer thick, quenching microstructure self tempering insufficiency is the main reason for the incompetent specific elongation of steel bars .Study on the tempering test showed that, at 450-500 ℃ for 50 min , tempering martensite the full decomposition of change, the steel bars plastic is greatly improved, various performance indicators meet the requirements of standard. After 450 ℃ ＋90 rain industrial tempering process, it can successfully save unqualified steel bars, reduce the loss of company.
关键词
PSB830
余热处理
延伸率低
回火
PSB830
remained heat treatment
fracture extensibility
low tempering
research
