摘要
采用箱式炉模拟热轧正火态20 mm厚Q245R钢板的高温烧成。检测了钢板的微观组织、拉伸性能、冲击性能和氢穿透时间(t_(H2))。结果表明:模拟高温烧成的钢板表层、1/4和1/2厚度处的微观组织与正火态类似,由带状珠光体和铁素体组成,烧成前后钢板的铁素体晶粒尺寸无明显变化;模拟高温烧成前后钢板的屈服强度、抗拉强度没有明显变化,断后伸长率升高,0℃冲击韧性下降,但均满足标准要求;正火态钢板表层、1/4和1/2厚度处的t_(H2)为2.70~4.35 min/mm^(2),远低于钢板双面或全表面涂搪玻璃要求的6.7 min/mm^(2)临界值,且从钢板表面至中心的t_(H2)值有明显差异;随着钢中碳质量分数的降低和珠光体体积分数的减少,玻璃层中气泡的数量和直径减小,有利于提高玻璃层质量。
Simulated high-temperature firing for hot-rolled then normalized 20-mm-thick Q245R steel plate was carried out in a box-type furnace. The steel plate was tested for microstructure, tensile and impact properties, and hydrogen permeation time(t_(H2)). The results showed that(a)the microstructures at surface layer, 1/4 and 1/2 thickness of the steel plate after simulated firings were similar to those of the normalized steel plate, all composed of banded pearlite and ferrite, and the grain size of ferrite of the steel plate did not vary obviously before and after firing;(b)compared with the steel plate before high-temperature firing, the steel plate after high-temperature firing did not vary considerably in tensile and impact properties, and exhibited higher elongation and lower but still acceptable impact toughness at 0 ℃;(c) the t_(H2)at surface layer, 1/4 and 1/2 thickness of the normalized steel plate was from 2.70 to 4.35 min/mm^(2) which was much less than the critical value of 6.7 min/mm2required for the steel plate being two-sided or overall surface lined with glass, and it varied evidently from surface to centre in t_(H2)value;and(d)as both mass fraction of carbon and volume fraction of pearlite in the steel decreased, so too did the quantity and size of bubbles in the glass-lined coating, which was beneficial to improve the quality of the glass-lined coating.
作者
孙全社
魏娇
王双成
SUN Quanshe;WEI Jiao;WANG Shuangcheng(Central Institute of R&D,Baoshan Iron and Steel Co.,Ltd.,Shanghai 201900,China)
出处
《上海金属》
CAS
2023年第2期64-68,94,共6页
Shanghai Metals
关键词
搪玻璃
中厚钢板
氢穿透时间
拉伸性能
冲击性能
glass lining
heavy and medium steel plate
hydrogen permeation time
tensile property
impact property
