CAJ | 학술논문

针对45＃硬线由Φ6．5 mm拉拔到Φ4．6 mm时发生断裂的问题，分析了其拉拔断口及表面裂纹形貌，用金相显微镜、扫描电镜对其金相组织、夹杂物及化学成分进行分析，结果表明：45＃硬线钢中存在大颗粒脆性夹杂物，降低了盘条表面的强度和塑性，使其在拉拔过程中出现横裂纹，继而引起拉拔断裂，盘条表层组织不均匀也增加了盘条断裂机率。提出了夹杂物控制和金相组织改进措施，改进后盘条拉拔到Φ3．8 mm时的断丝率不足1．5％。
침대45＃경선유Φ6．5 mm랍발도Φ4．6 mm시발생단렬적문제，분석료기랍발단구급표면렬문형모，용금상현미경、소묘전경대기금상조직、협잡물급화학성분진행분석，결과표명：45＃경선강중존재대과립취성협잡물，강저료반조표면적강도화소성，사기재랍발과정중출현횡렬문，계이인기랍발단렬，반조표층조직불균균야증가료반조단렬궤솔。제출료협잡물공제화금상조직개진조시，개진후반조랍발도Φ3．8 mm시적단사솔불족1．5％。
To solve the problem of 45#hard wire:breaking when drew from Φ6.5 to 4.6 mm, its fracture surface and the surface cracks morphology are analyzed as well as its metallographic structure, inclusion and chemical composition with metallographic microscope and SEM.It is showed from the result that there is large-size brittle inclusion in it and so the surface strength and plasticity of the wire bar reduced, and trans-verse crack takes place on it in drawing and then broken.Besides, not homogeneous surface structure of wire bar increases the rate of break.The measures in controlling inclusion and improving metallographic structure are proposed.After improvement the break rate of wire bar is below 1.5%when drew toΦ3.8 mm.