Analysis on split-head cracking of Y1Cr13 stainless rolled bar
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摘要: 针对某厂生产的Y1Cr13不锈钢在轧制过程产生劈头开裂的问题,采用金相显微镜、扫描电子显微镜、小样电解等分析检测方法,从夹杂物微观形貌角度对钢劈头开裂样中硫化物的微观形貌特征进行了表征分析,并探究了Y1Cr13不锈钢轧制时劈头开裂形成的原因。结果表明:该不锈钢轧材存在大量长条状硫化物,硫化物长宽比较大,长宽比分布在3以内的夹杂物占比为65.4%,长宽比大于3的夹杂物占比为34.6%,硫化物的国标评级为:粗系4.5级,细系5.5级,德标评级为3-3级;钢中过多的热脆细长条状硫化锰和锰铁硫化物是劈头开裂的主要原因。采用镁、碲等新工艺可对硫化物形态进行改质,将其控制为球形或纺锤形,并提高硫化物硬度,轧制时不易变形;通过适当减少钢中的[S]含量以及提高钢中Mn/S等措施可减少钢中的(Mn,Fe)硫化物。Abstract: In order to find out the causes of split-head cracking of Y1Cr13 stainless steel in the rolling process, the splitting samples of steel were analyzed and characterized from the view of inclusions microstructure with a metallographic microscope, a scanning electron microscope and the method of electrolytic etching. Also, the causes of split-head crackingof Y1Cr13 stainless steel during the rolling process were explored. The results show that there exist a lot of long strip sulfides in rolled steel, and the ratio of length/width of sulfides is large. The proportion of the inclusions with length/width ratio below 3 is 65.4%. The proportion of the inclusions with length/width ratio above 3 is 34.6%. The standard ratings of sulfides are 4.5 for coarse series, 5.5 for fine series, and 3-3 for German standard. A large number of long strip hot shortness manganese sulfides and ferromanganese sulfides are the main causes of split-head cracking of Y1Cr13 rolled bar. Such as magnesium and tellurium can be used to modify the form of sulfide into a spherical or spindle shape, and increase the hardness of the sulfide, making it difficult to deform during rolling. The (Mn, Fe) sulfide in steel can be reduced by properly reducing [S] content and increasing Mn/S in steel.
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Key words:
- Y1Cr13 stainless steel /
- split-head /
- cracking /
- manganesesulfide /
- ferromanganesesulfide
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表 1 试验钢的主要化学成分
Table 1. Main chemical compositions of experimental steels
% 厂家 C Si Mn P S Cr Mo Ni A 0.13 0.54 1.15 0.027 0.31 12.89 0.04 B 0.122 0.229 0.957 0.026 0.350 12.300 0.105 C 0.120 0.430 1.160 0.018 0.270 12.790 0.260 表 2 三个厂硫化物评级对比
Table 2. Comparison of inclusions rating of samples provided by three plants
厂家 国标评级(GBT 10516—2005) 德标评级 A 粗系4.5级,细系5.5级 3-3级 B 粗系3.0级,细系5.5级 2-3级 C 粗系1.5级,细系5.5级 2-2级 -
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