H型钢裂纹研究

Research on Cracks of H type Steel

研究了河北某大型H型钢厂采用半敞开方式浇注的H型钢腹板裂纹产生的原因。结果表明：解决H型钢腹板裂纹分为三个阶段，第一阶段，刚投产时出现腹板裂纹几率高达60％～70％，分析主要是由于钢中S、P含量偏高，把其含量降低到[s]〈0．02％、[P]〈0．025％时，可把腹板裂纹控制在16％以内，此时再降低钢中S、P含量效果不明显。第二阶段最为重要，在该厂选取了26块有代表性裂纹的试样进行了细致的研究，研究认为：腹板裂纹主要是由钢中夹杂物和轧制因素造成，其中由夹杂物因素形成的裂纹占69．2％，由轧制因素形成的裂纹占30．8％，提出改进措施后可把腹板裂纹几率降低到1％以内。第三阶段，要想再降低H型钢腹板裂纹几率，应对生产工艺进行优化进一步降低钢中O、S、P以及夹杂物含量，这样才可以取得较明显的效果。

The paper researched the reason of cracks in H beam blanks which are produced by semi-open way in a large H beam steel factory of HeBei. The study shows that： solve the crack of H beam steel is divided into three stages, the first stage , when the probability of crack in H beam steel stomach plank just as much as 60% -70% put into operation, mainly due to high content of S, P in steel by analysis, When down to [S]〈0.02 % ,[P]〈0.025, the probability of crack in H beam steel stomach plank down to within 16 %. Lower content of S, P again, effect was not obvious at this time. The second stage, research on se- lected 26 specimens of representative crack in the plant,The study shows that： the crack of stomach plank caused by inclusion and rolling, the crack caused by inclusion formation takes 69.2%, the crack caused by rolling formation takes 30.8% , the probability of crack in H beam steel down to less then 1% after making improvements. The third stage, in order to further reduce the probability of crack again, the process should be optimized to further reduce content of S, P, and inclusion in steel, on- ly, in this way can we obtain more significant results.