经济型X80管线钢的研制开发

研究包括加热工艺、控轧制度和控冷工艺在内的经济型X80管线钢工艺技术。结果表明，通过控制加热温度不超过1180℃，奥氏体晶粒尺寸可控制在80μm以内。通过提高粗轧阶段最后1个道次的压下率，使其达到20%以上，可使钢板心部奥氏体晶粒得到充分细化；通过降低终冷温度和提高冷却速率等工艺参数，可得到细小的板条贝氏体和针状铁素体组织；采用JCOE工艺制管后，X80屈服强度提高，为降低产品生产成本提供了可能。目前，该公司已实现无钼经济型X80管线钢的稳定生产。

Research and development of low-cost X80 pipeline steel

An overview of reduced production technology for X80 plates was introduced，including heating process， controlled rolling and controlled cooling process. The results showed that by controlling the heating temperature below1180℃，the austenite grain can be controled less than 80 μm. By increasing the reduction rate at the last one pass during rough rolling to 20% or more，the center austenite grain can be refined completely. Eventually the microstructure of ultra-fine lath bainite and acicular ferrite was obtained by decreasing the finish cooling temperature and increasing the cooling rate. After applying the JCOE process to make the pipe，the yield strength of X80 plates raised，which can provide a possibility to reduce product cost. At present，a batch production of low cost X80 plate without molybdenum alloy was achieved in the company.