250t转炉烟罩加料溜槽寿命研究及其焊接工艺

Study on Service Life of Charging Chute of Fume Hood of 250 t Converter and Chute Welding Technology

针对转炉烟罩加料溜槽寿命过短的问题进行失效分析,发现堆焊层厚度不足,焊后热处理效果不佳,裂纹扩展,宽窄不均,呈现热疲劳特征,并可见碳化物和共晶组织脱落。根据加料溜槽底面及侧面工作状态的不同,底面改用堆焊层硬度稍高的焊条堆焊,使堆焊层耐磨性增加,侧面改用韧性较好、焊态硬度稍低的不锈钢堆焊焊条堆焊,既改进了溜槽性能,又降低了生产成本。

This paper studies the problem of low service life of charging chute of fume hood of 250 t converter. The failure reasons can be attributed as follows： the thickness of welding overlay was not large enough; the effect of treatment after welding was not good; the cracks expanded with the feature of thermal fatigue, carbides and eutectic structure dropped out, etc. Based on different working conditions for the bottom and side surface of charging chute , high hardness welding materials were used on the bottom surface so as to improve its abrasion-resistance, and stainless welding materials with better toughness and less hardness were adopted on the side surface. As a result, the service life increased and the production cost reduced.