螺旋埋弧焊管制管前后力学性能变化及其影响因素

研究了Q235B～API X80钢级、壁厚6.3 ～18.4 mm热轧卷板的化学成分、组织及性能以及Φ355.6 mm～Φ1 219 mm的螺旋埋弧焊管制管前后力学性能变化的一般规律，分析了螺旋焊管制造过程及试样展平过程产生的包申格效应对钢管拉伸性能及韧性的影响。研究发现，包申格效应与钢级（或者强度水平）相关性最强，X52～X65钢的包申格效应最为明显，而X52以下及X70以上钢级的包申格效应则不太明显；对于抗拉强度，所试验钢级制管前后基本一致。材料的成分及显微组织是影响包申格效应的主要因素，静水压试验工序也会使螺旋埋弧焊管的屈服强度相比焊接后钢管显著提高，制管后夏比冲击性能变化无明显规律。

Changes of Mechanical Properties and Its Influencing Factors of Spiral Submerged Arc Welded Pipes before and after Pipe-making Process

The composition，structure and performance of Q235B~API X80 steel with wall thickness ranging from 6.3 mm to 18.4 mm were studied，as well as the general rules of mechanical properties changes of spiral submerged arc welded pipes before and after pipe-making process with outer diameter ranging from 355.6 mm to 1 219 mm，and the influence of the bauschengge effect on the tensile properties and toughness of the spiral welded pipe was analyzed. It is found that bauschinger effect has the strongest correlation with steel grade（or strength level），and the bauschinger effect is the most obvious for steel grades X52~X65，while the bauschinger effect is less obvious for steel grades below X52 and above X70. The tensile strength of the tested steel pipe is basically the same. The composition and microstructure of the material are the main factors affecting the bauschinger effect. The yield strength of spiral submerged arc welded steel pipe is significantly improved compared with that of welded steel pipe after hydrostatic test. Charpy impact performance after pipe manufacture changes irregularly.