摘要
对探伤不合格的厚度不小于25mm钢板进行取样，分别做了低倍酸洗、刨削、金相、SEM及能谱分析，分析认为探伤不合格的主要原因是中心偏析分层、内部裂纹、中心部位的氢致裂纹、大颗粒外来夹杂（夹渣）。在生产压缩比小于6．0的宽厚规格钢板时，应围绕钢水质量、板坯低倍质量、缓冷时效（≥48h）、轧后时效（≥24h）有针对性地选择工艺路线，其中钢水质量主要为钢中氢的质量分数应控制在2．0×10^-6以下，硫的质量分数控制在0．010％以下，氧的质量分数控制在25×10^-6以下；板坯低倍质量主要由过热度（15～25℃）、拉速（恒拉速）、动态配水、动态软压下、液面控制（±4mm）及设备工况等综合工艺条件决定。
This article makes series of defect analysis by acid-etching, planning, metallographic structure, SEM and energy spectrum analysis on the samples from heavy gauge （≥25 mm） plates, which are failed to pass ultrasonic detection. It is considered that the main reasons for failure to pass the detection are central segregation laminar;intermediate cracks, central hydrogen induced cracks and exotic inclusions. When the heavy gauge plate is produced which compression ratio is less than 6.0 and the detection required, the production process route should be selected which focused on the steel quality, level of macro etching of slab, aging treatment （≥48 h） of slabs at the condition of soft cooling and rolled plates aging treatment （≥24 h）. For the liquid steel quality, [H] must be controlled below to 2.0×10^-6 , [S] below to 0. 010% and total oxygen [O] less than 25×10^-6. And the quality of the slab is mainly decided by the series of process conditions including superheat （15～25℃） of liquid steel, cast speed （constant）, dynamic secondary cooling system, DSR, mould level control （±4mm） and equipment work conditions of caster.
出处
《钢铁研究学报》
CAS
CSCD
北大核心
2010年第9期13-17,62,共6页
Journal of Iron and Steel Research
关键词
探伤
中厚板
生产工艺
分析
ultrasonic detection
heavy and medium plate
process
analysis
