XU Changgan ZENG Zhongping Beijing University of Aeronautics and Astronautics
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Beijing
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China
金属学报(英文版)
The plots of load vs deflection(P-D)for two ultra-strength steels 30CrMnSiNi2A and 300M has been examined on a Charpy impact tester with digital memory and microcomputer. A criterion was found to availably represent the dynamic fracture toughness,K_(Ic)~D ,of the steels under impact loading.The K_(Ic)~D,.can be calculated with suggesting that the turning point of change in compliance on the P-D plot is the point of destabilized crack propagation.The K_(Ic)~D of steel 300M,quenched at 870℃ ,separately tempered at 300℃ and 450℃,was esti- mated to be 55—70 MN/m~(3/2)and 54—67 MN/m~(3/2)respectively.The K_(Ic)calculated with accuracy about 20% seems to be available to the engineering evaluation.
关键词:
ultra-strength steel
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null
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null
谭伟
,
徐滨士
,
韩文政
,
冯少武
,
冯建林
,
钟群鹏
金属学报
采用Gleeble--1500热模拟试验机模拟了22SiMn2TiB超高强度钢焊接
接头热影响区的组织, 并利用Solaron SL1280B恒电位仪测定了热模
拟HAZ各区在3.5\%NaCl水溶液中的极化行为, 建立了热模拟组织与其
在3.5%NaCl水溶液中腐蚀行为的关系. 结果表明: 22SiMn2TiB超高
强度钢显微组织转变受碳和硼的扩散、偏聚和碳化物的脱溶所控制,
且依赖于最高加热温度θmax和冷却时间t8/5.
虽然热模拟组织发生了变化,但热模拟HAZ各区在3.5%NaCl水溶液中
的极化曲线的形状和趋势大致相同, 组织变化对自腐蚀电位有一定的
影响, 但影响幅度不大. 自腐蚀电位与腐蚀电流之间无对应关系; 腐
蚀电流的大小由氧的极限扩散电流决定. 在电偶腐蚀过程中, 焊接熔合区作为阳极而溶解, 需重点防护
关键词:
超高强度钢
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heat affected zone (HAZ)
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thermal simulation
