X65钢板板端开裂原因分析
Cause Analysis of the Shear Crack on X65 Steel Plate
魏伟荣,李云龙,李记科,聂向晖
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作者单位:1中海石油(中国)有限公司深圳分公司
2中国石油天然气集团公司管材研究所
中文关键字:裂纹;剪刃间隙;切应力;光亮区
英文关键字:crack; blade clearance; shear stress; bright region
中文摘要:本文对30.2mm厚X65钢板板端裂纹的成因及其对钢板性能的影响进行了试验与分析。结果表明:这种板端裂纹产生于钢板的头部及尾部剪切面上,裂纹及其附近未见明显的夹杂及组织异常;钢板未开裂处的拉伸和冷弯性能符合相关规范要求。钢板剪切过程中较小的剪刃间隙是板端开裂的主要原因,当与剪切方向呈45°的最大剪应力超过钢板剪切强度极限τmax时,钢板端面沿切应力方向开裂,由于剪刃间隙较小,导致了剪刃磨损严重,在板端断面上表现为较宽且粗糙的光亮区表面。
英文摘要:The cause of the shear crack on 30.2 mm thickness X65 grade steel plate and its influence on the mechanical property were analyzed in this paper. The results indicated: this kind of crack mainly located on the top and end shear plane of the plates, no obvious inclusion and abnormal microstructure were found on the crack and adjacent region, the tensile and cold bending property of the plates within the demands of the specification. Small blade clearance during the shearing process was the main reason of this kind of crack, if the maximum shear stress on the 45 degree exceeding the shear strength τmax of the plate, the shear surface cracked, at the same time, the blades were worn severely and the bright region on the shear surface was broad and coarse.