热煨制过程对X100管线钢组织与性能的影响

Effect of reheat process on microstructure and properties of X100 pipeline steel

对X100管线钢采用淬火-回火型弯制技术制备弯管时的组织与性能进行了研究。结果表明,对于组织中分布有弥散残留奥氏体和Fe3C的粒状贝氏体管线钢X100而言,当回火温度为550℃时,其组织均匀性最好,材料硬度适中。当煨制热制度为950℃淬火+550℃回火时,其显微组织为贝氏体、多边铁素体和珠光体,硬度可与母材相匹配。冲击断口分析表明,在-20℃时,X100钢断口的纤维区、放射区、剪切区都有良好的韧窝形状,表明在该煨制加热制度下,X100钢可获得良好的韧性。

The microstructure and toughness characteristics of reheated X100 pipe steel by quenching-tempering type bending process were studied.The results show that the distribution in granular banite is of dispersed residual austenite and Fe3C.For the banite pipeline steel X100,when the tempering temperature is at 550 ℃,it will have the best homogeneity,and the hardness is moderate.When the reheating process is quenching at 950 ℃ and tempering at 550 ℃,its microstructure is consisted of banite,polygonal ferrite,and pearlite,and its hardness can be matched with the original material.The analysis of the impact fracture shows that,when it is at-20 ℃,the fibred area,the radiating area,and the shearing area of the fracture of X100 steel are all of the fine tough shape,which shows that such heat-treated process can have heat-treated bended tube attained a good toughened result.