轧制工艺对X70耐酸管线钢抗HIC和力学性能的影响

研究了终轧温度和在线冷却方式对X70级耐酸管线钢力学性能和抗HIC性能的影响。结果显示:层流冷却相对于在线空冷,钢板的强韧性有明显提高,两种工艺下钢板的硬度指标相当;在相同冷却工艺下,提高终轧温度有利于屈服强度和抗拉强度的提高;抗HIC性能只与铸坯质量有关,与轧制工艺、组织状态、晶粒度大小无关。根据研究的结果进行了X70级别耐酸管线钢的工业试制,所得X70管线钢在强韧性满足标准要求的前提下,保持了良好的抗HIC性能。

Effects of Rolling Process on Mechanical Property and HIC Resistance Performance of X70 Sour-service Pipeline Steel

The effects of finishing temperature and cooling-down method on the mechanical property and HIC resistance performance of X70 sour-service pipeline steel are studied. The sample produced by laminar coohng method shows higher strength and better toughness than air cooling. With the finishing temperature increasing, YS and TS becomes better when treated under the same cooling method. It is found that HIC resistance performance only relates with quality of casting billet rather than the rolling process, grain size and microstructure. According to the results of experimental studies, X70 sour-service pipeline steel is produced successfully in mill, coils meet the requirements of the strength and toughness of pipeline steels, and maintains a good performance on HIC resistance.