Abstract: The surface temperature of profiled beam blank of Nb microalloying steel SM490YB-0.09～0. 13C,1.35 ~1.50Mn,0.04～0.06Nb during concasting by CIT-M Infrared Pyrometer. The results showed that the traverse surface temperature of beam blank was uneven, the surface temperature of beam at measured location in secondary cooling and straightening area were generally in the brittle low temperature range between 650 ℃ and 750℃ of steel SM490YB; and due to interval water spraying cooling between supporting rollers,the re-rise rate of temperature of beam surface between some supporting rollers in secondary cooling area was higher than 100 ℃/m the limits of metallurgical rules. It shall be to adopt weakening cooling process during casting profiled beam and adjust distribution of spraying nomles in order to increase the surface quality of profiled beam.

摘要： 采用CIT-M型红外测温线性化传感器测定了马钢Nb 微合金化钢 SM490YB(%:0.09～0. 13C, 1.35～1.50Mn,0.04～0.06Nb)异型坯在连铸过程中的表面温度，结果表明异型坯横向表面温度不均匀；在二冷 区测量位置和矫直区，铸坯表面温度基本处于SM490YB钢的低温脆性区(650～750℃);在二冷2段由于支撑 棍间间隔喷水冷却，温度回复大于冶金规则允许的最大限度100 ℃/m。SM490YB异型坯浇铸应采用弱冷工 艺，同时调整冷却喷嘴的布置，以提高异型坯表面质量。

关键词: Nb微合金化钢, 连铸异型坯, 表面温度