多相组织管线钢的应变时效敏感性

Strain aging sensitivity of multi-phase pipeline steel

通过对多相组织管线钢进行横向预应变模拟管线钢在制管过程中的横向扩径,进而研究横向预应变对多相组织管线钢横向和纵向拉伸应变行为的影响.发现多相组织X80管线钢在横向预应变后的加工硬化表现出明显的方向性,平行于预应变方向加工硬化高,但在低于2%预应变条件下屈强比仍能保持在0.95以下.垂直于预应变方向在预应变后仍能保持连续屈服的拉伸应变特征,具有较低的屈强比(小于0.75)以及高的均匀延伸率.此外通过对预应变后钢板进行时效处理,以此研究制管后防腐热涂覆对管线钢拉伸应变行为的影响.结果表明多相组织管线钢拥有很好的抗时效稳定性.

Transversal pre-strain experiments were carried out to investigate the effect of transversal hole enlargement on the tensile strain behavior of multi-phase pipeline steel. Experimental results indicate that the work hardening behavior after pre-strain treatment has directional characterization. When the pre-strain direction parallels to the final tensile strain direction, the work hardening rate is very high. Only when the pre-strain rate is lower than 2%, the yield ratio can keep below 0.95. When the tensile strain direction is perpendicular to the pre-strain direction, the strain-stress curves can maintain a continuous yield character, which has low yield ratio （below 0.75） and high uniform elongation rate. In addition, strain aging treatment was carried out to investigate the effect of anti-corrosion thermal coating treatment on the tensile strain behavior of multi-phase pipeline steel. It is shown that the multi-phase pipeline steel has excellent anti-aging stability.