北京科技大学学报
北京科技大學學報
북경과기대학학보
JOURNAL OF UNIVERSITY OF SCIENCE AND TECHNOLOGY BEIJING
2014年
1期
37-41
,共5页
周红凯%李龙飞%杨王玥%孙祖庆
週紅凱%李龍飛%楊王玥%孫祖慶
주홍개%리룡비%양왕모%손조경
低碳钢%合金钢%相变%贝氏体%奥氏体%力学性能
低碳鋼%閤金鋼%相變%貝氏體%奧氏體%力學性能
저탄강%합금강%상변%패씨체%오씨체%역학성능
low carbon steel%alloy steel%phase transitions%bainite%austenite%mechanical properties
通过Gleeble-1500热模拟压缩试验,借助光学显微镜、扫描电镜、X射线衍射及拉伸试验等,研究一种低碳Mn-Si钢在基于热轧动态相变的热轧TRIP钢工艺和基于贝氏体等温处理工艺下的组织与力学性能,比较了通过两种工艺获得的不同复相组织状态对材料的加工硬化能力的影响。结果表明:实验钢在基于动态相变的热轧TRIP钢工艺下获得了以细晶铁素体为基体和贝氏体、残余奥氏体组成的复相组织,而在基于贝氏体等温处理工艺下得到了以板条贝氏体为基体和残余奥氏体组成的复相组织,前者中残余奥氏体含量较高且其碳含量也较高。实验钢具有以板条贝氏体为基体的复相组织时屈服强度和抗拉强度较高;但由于残余奥氏体稳定性较差,实验钢的加工硬化能力较弱,导致其均匀延伸率和总延伸率较小。
通過Gleeble-1500熱模擬壓縮試驗,藉助光學顯微鏡、掃描電鏡、X射線衍射及拉伸試驗等,研究一種低碳Mn-Si鋼在基于熱軋動態相變的熱軋TRIP鋼工藝和基于貝氏體等溫處理工藝下的組織與力學性能,比較瞭通過兩種工藝穫得的不同複相組織狀態對材料的加工硬化能力的影響。結果錶明:實驗鋼在基于動態相變的熱軋TRIP鋼工藝下穫得瞭以細晶鐵素體為基體和貝氏體、殘餘奧氏體組成的複相組織,而在基于貝氏體等溫處理工藝下得到瞭以闆條貝氏體為基體和殘餘奧氏體組成的複相組織,前者中殘餘奧氏體含量較高且其碳含量也較高。實驗鋼具有以闆條貝氏體為基體的複相組織時屈服彊度和抗拉彊度較高;但由于殘餘奧氏體穩定性較差,實驗鋼的加工硬化能力較弱,導緻其均勻延伸率和總延伸率較小。
통과Gleeble-1500열모의압축시험,차조광학현미경、소묘전경、X사선연사급랍신시험등,연구일충저탄Mn-Si강재기우열알동태상변적열알TRIP강공예화기우패씨체등온처리공예하적조직여역학성능,비교료통과량충공예획득적불동복상조직상태대재료적가공경화능력적영향。결과표명:실험강재기우동태상변적열알TRIP강공예하획득료이세정철소체위기체화패씨체、잔여오씨체조성적복상조직,이재기우패씨체등온처리공예하득도료이판조패씨체위기체화잔여오씨체조성적복상조직,전자중잔여오씨체함량교고차기탄함량야교고。실험강구유이판조패씨체위기체적복상조직시굴복강도화항랍강도교고;단유우잔여오씨체은정성교차,실험강적가공경화능력교약,도치기균균연신솔화총연신솔교소。
The microstructure and mechanical properties of a low-carbon Mn-Si multiphase steel treated by two different thermal-mechanical processes, the hot-rolling process for TRIP steel based on dynamic transformation of undercooled austenite and the process based on bainitic isothermal treatment, were investigated by hot uniaxial compression tests on a Gleeble-1500 hot simulator, in combi-nation with optical microscopy, scanning electron microscopy, X-ray diffraction and tensile testing. A comparison was carried out to analyze the influence of multiple-phase microstructure states by the two processes on the work-hardening behaviors of the steel. The multiple-phase microstructure consisting of fine-grained ferrite matrix, bainite, and retained austenite is formed by the hot-rolling process for TRIP steel based on dynamic transformation of undercooled austenite, but the multiple-phase microstructure which is composed of lath bainite matrix and retained austenite is formed by the process based on bainitic isothermal treatment. The volume frac-tion of retained austenite and the mass fraction of carbon in retained austenite in the former are higher than those in the latter. The yield strength and tensile strength of the steel with the multiple-phase microstructure consisting of lath bainite matrix and retained austenite are higher;but the steel has lower uniform elongation and total elongation, which should be attributed to its lower work-hardening capa-bility resulting from the lower stability of retained austenite.