CAJ | 학술논문

在不预热条件下，采用熔化极气体保护焊（ GMAW）对1200 MPa高强耐磨钢进行多层多道焊工艺性试验，并对试样进行夏比冲击试验，利用金相显微镜及扫描电子显微镜（ SEM）研究焊缝组织形态与断口形貌，并通过对冲击断口的形貌分析研究其断裂机制。试验结果表明：焊缝组织主要由细小的针状铁素体组织和粗大的先共析铁素体组织构成，随焊接热输入增大，先共析铁素体所占比例增大，针状铁素体比例减小，由此导致焊缝冲击韧性下降；不同温度下的冲击试验表明，焊缝冲击吸收能量均高于母材，结合断口形貌分析，焊接接头的焊缝区表现出良好的冲击韧性。
재불예열조건하，채용용화겁기체보호한（ GMAW）대1200 MPa고강내마강진행다층다도한공예성시험，병대시양진행하비충격시험，이용금상현미경급소묘전자현미경（ SEM）연구한봉조직형태여단구형모，병통과대충격단구적형모분석연구기단렬궤제。시험결과표명：한봉조직주요유세소적침상철소체조직화조대적선공석철소체조직구성，수한접열수입증대，선공석철소체소점비례증대，침상철소체비례감소，유차도치한봉충격인성하강；불동온도하적충격시험표명，한봉충격흡수능량균고우모재，결합단구형모분석，한접접두적한봉구표현출량호적충격인성。
1 200 MPa high-strength wear-resistant steel was welded by gas metal arc welding ( GMAW) with dif-ferent heat input without preheating,and Charpy impact test was done on samples.Microstructure of weld metal and fracture morphology were investigated by means of optical microscopy and scanning electron microscopy ( SEM) .The test results indicate that the weld metal is composed of acicular ferrite ( AF) and proeutectoid fer-rite ( PF) .With the increasing of heat input, the percentage of acicular ferrite decreases while the percentage of proeutectoid ferrite increases, consequently, the impact toughness of welding joint declines.Impact test at dif-ferent temperature shows that the impact toughness of weld metal is much higher than base metal.