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一、前言应变时效冲击值(ak)是低合金桥梁钢板(16Mn桥)的重要机械性能之一,也是限制16兴起,窄而长(L≥16米)桥板的需求量与日俱增。由于冶炼工艺未取得实质性的改进,化学成分偏析、有害夹杂形态控制困难、成品规格与坯料的矛盾迫使采取纵轧到底的不利轧制方式,更加剧了硫化物等有害夹杂的作用。因此,提高特殊规格桥梁板性能合格率的难度就更加大了。本文根据数理统计的结果,探讨了碳当量、成品厚度对桥梁钢板关键性能的影响;提出了按碳当量开坯、按碳当量安排轧制规格的方法;并就轧制工艺、显微组织、夹杂Mn桥板热轧性能合格率提高的关键因素。近几年来,在16Mn桥板的7个必检项目中,应变时效冲击值不合批数占总不合批数的39.6～73.6％(见表1)。从市场情况来看,随着大跨度焊接桥梁
I. Preface The strain aging impact value (ak) is one of the important mechanical properties of low alloyed bridge steel plates (16Mn bridges), which is also the limit of 16 rise. The demand for narrow and long (L≥16m) bridge plates is increasing day by day. Due to the smelting process has not been substantially improved, chemical composition segregation, harmful inclusions control difficult, the contradiction between the finished product specifications and billet forced the adoption of rolling in the end of the adverse rolling mode, but also exacerbated the role of sulfide and other harmful inclusions. Therefore, to improve the performance of special specifications of bridge performance rate of the more difficult. Based on the results of mathematical statistics, this paper discusses the effect of carbon equivalent and product thickness on the key performance of bridge steel plate. The paper proposes a method of rolling the steel plate according to the carbon equivalent and arranging the rolling specifications according to the carbon equivalent. The rolling process, microstructure, The Key Factors to Improve the Passing Rate of Hot Rolling Inclusion Mn Bridge. In recent years, among the 16 mandatory inspection items of 16Mn bridge slabs, 39.6% to 73.6% of the total number of non-conforming impact strain aging impact values (see Table 1). From the market situation, with the long-span welded bridge