冷軋變形對316LN奧氏體不銹鋼組織和性能的影響
發(fā)布時間：2018-11-05 15:01
【摘要】：奧氏體不銹鋼由于具有優(yōu)良的韌塑性、抗高溫氧化性以及耐腐蝕性等,被廣泛用于食品、化工等領(lǐng)域,但固溶態(tài)奧氏體不銹鋼的強度比較低,因而奧氏體不銹鋼很少作為結(jié)構(gòu)材料使用,通常需要借助加工硬化的方式來提高其綜合性能,以滿足其使用要求,冷軋作為一種有效的加工硬化方式,也常常被人們用作改善不銹鋼性能的手段。近些年來,國內(nèi)外有許多關(guān)于室溫冷軋對奧氏體不銹鋼性能影響的研究文獻,但鮮有人系統(tǒng)地研究室溫冷軋與深冷軋制對316 LN奧氏體不銹鋼組織和性能的影響,且國內(nèi)外深冷軋制研究的對象也都基本局限在有色金屬方面。鑒于上述情況,本文將全面地研究冷軋變形對316 LN奧氏體不銹鋼組織和性能的影響,為316 LN奧氏體不銹鋼的開發(fā)和應(yīng)用提供實驗依據(jù)和技術(shù)支撐。本文以316 LN奧氏體不銹鋼為研究對象,隨后分別進行室溫狀態(tài)和深冷狀態(tài)(液氮)下的軋制,并對軋制后316 LN奧氏體不銹鋼力學性能的變化進行詳細研究,借助金相顯微鏡(OM)、掃描電鏡(SEM)、透射電鏡(TEM)等微觀組織分析手段對其組織演變過程進行系統(tǒng)表征,結(jié)果表明:奧氏體不銹鋼在軋制變形過程中均發(fā)生了形變誘導馬氏體相變,且隨著軋制變形量的增大,形變誘導馬氏體所占的體積分數(shù)也越大。室溫軋制狀態(tài)下,形變誘導馬氏體的體積分數(shù)由11.1%(30%)上升到72.3%(90%)。深冷軋制狀態(tài)下,軋制變形量為30%時,形變誘導馬氏體的體積分數(shù)為58.7%,變形量為50%時,其體積分數(shù)為78.7%,當軋制變形量繼續(xù)增大為70%時,奧氏體組織已完全轉(zhuǎn)變成馬氏體。經(jīng)同一軋制狀態(tài)下各變形量間的比較以及兩種不同軋制狀態(tài)下不同變形量的對比可知:深冷軋制狀態(tài)下形變誘導馬氏體相變的速率遠遠高于室溫軋制狀態(tài),且深冷軋制下奧氏體組織能100%轉(zhuǎn)化成馬氏體。室溫軋制過程中,在變形量較小的情況下,變形的組織中主要是以位錯的增殖和纏結(jié)為主,同時有少量的形變孿晶和板條馬氏體生成;當變形量較大時,變形組織則以形變孿晶為主,并伴隨有少量高密度位錯墻和位錯胞,同時形變誘導馬氏體大量出現(xiàn)。深冷軋制過程中,在變形量較小時,已出現(xiàn)大量形變誘導馬氏體,當變形量進一步增大到70%時,組織內(nèi)部已完全發(fā)生形變誘導馬氏體相變。隨著變形量的增大,奧氏體不銹鋼的硬度值和強度值也隨之增大,前期呈迅速上升狀態(tài),后期逐漸趨于平穩(wěn),且同一變形量,深冷軋制后奧氏體不銹鋼的硬度值和強度值均明顯高于室溫冷軋:變形量為90%時,深冷軋制后奧氏體不銹鋼的硬度值約為原始試樣的3倍,屈服強度和抗拉強度約為原始試樣的7倍和3倍;室溫冷軋后試樣硬度值約為原始試樣的2.6倍,屈服強度和抗拉強度為原始試樣的4.9倍和2.2倍。試樣拉伸斷口形貌均由韌性斷裂向韌性和準解理混合型斷裂轉(zhuǎn)變。延伸率隨著軋制變形量的增大而迅速降低,與力學性能指標變化趨勢相反:室溫軋制時,試樣的延伸率由3.5%(30%)下降至2.5%(90%);深冷軋制狀態(tài),延伸率由2.3%(30%)下降至1.5%(90%)。
[Abstract]:The austenitic stainless steel is widely used in the fields of food, chemical industry and the like due to the excellent toughness, high temperature oxidation resistance, corrosion resistance and the like, but the strength of the solid soluble austenitic stainless steel is low, so that the austenitic stainless steel is rarely used as a structural material, it is often necessary to improve its comprehensive performance by means of a cold rolling to meet its use requirements, cold rolling as an efficient cold rolling method, and often used as a means of improving the performance of the stainless steel. In recent years, there are many studies on the effect of cold rolling on the properties of austenitic stainless steel at room temperature, but few have systematically studied the effect of cold rolling and cryogenic rolling on the microstructure and properties of 316LN austenitic stainless steel. And the object of cryogenic rolling research both at home and abroad is also limited to non-ferrous metals. In view of the above situation, this paper will comprehensively study the effect of cold rolling deformation on microstructure and properties of 316LN austenitic stainless steel, and provide experimental basis and technical support for the development and application of 316LN austenitic stainless steel. In this paper, 316 LN austenitic stainless steel was used as the research object, then the rolling at room temperature and cryogenic state (liquid nitrogen) were carried out respectively, and the mechanical properties of 316L austenitic stainless steel after rolling were studied in detail. The microstructure evolution of austenitic stainless steel is characterized by means of microstructure analysis such as transmission electron microscope (TEM). The results show that the deformation induced martensite transformation in the process of rolling deformation of austenitic stainless steel, and with the increase of rolling deformation, The larger the volume fraction of the deformation-induced martensite. In the condition of room temperature rolling, the volume fraction of deformation-induced martensite increased from 11.1% (30%) to 72.3% (90%). In the state of cryogenic rolling, when the rolling deformation amount is 30%, the volume fraction of deformation-induced martensite is 58. 7%, and when the deformation amount is 50%, its volume fraction is 77.8%, and when the rolling deformation continues to increase to 70%, the austenite structure has completely transformed into martensite. The comparison between the deformation amounts in the same rolling state and the comparison of different deformation amounts in two different rolling states shows that the rate of deformation induced martensite transformation in deep cooling rolling state is much higher than that of the room temperature rolling state, and the austenite structure can be converted into martensite by 100% under the deep cooling rolling state. In the process of rolling at room temperature, under the condition that the deformation amount is small, the deformation is mainly caused by the propagation and entanglement of dislocations, and at the same time, a small amount of the deformed columnar crystal and the lath martensite are generated, and when the deformation amount is large, the deformation structure mainly takes the deformed columnar crystal as the main structure, It is accompanied by a small number of high density dislocation walls and dislocation cells, and deformation induces a great deal of martensite. In the process of deep cooling, a large number of deformation-induced martensite has occurred during low deformation. When the deformation amount is further increased to 70%, the deformation-induced martensite transformation is completely induced inside the structure. With the increase of the deformation amount, the hardness value and the strength value of the austenitic stainless steel are also increased, the early stage is in a rapidly rising state, the later stage gradually becomes stable, and the same deformation amount, the hardness value and the strength value of the austenitic stainless steel after the deep cooling rolling are obviously higher than that of the room temperature cold rolling: When the deformation amount is 90%, the hardness value of the austenitic stainless steel after the deep cooling rolling is about 3 times of the original sample, the yield strength and the tensile strength are about 7 times and 3 times of the original sample, the hardness value of the sample after cold rolling at room temperature is about 2.6 times of the original sample, Yield strength and tensile strength were 4. 9 and 2. 2 times the original sample. The tensile fracture morphology of specimen was changed from ductile fracture to ductile fracture and quasi-cleavage mixed fracture. The elongation of the specimen decreases rapidly with the increase of rolling deformation and the change trend of mechanical property index is opposite: the elongation of the specimen decreases from 3.5% (30%) to 2.5% (90%) when rolling at room temperature. The elongation of cryogenic rolling decreases from 2.3% (30%) to 1.5% (90%).
【學位授予單位】：河南科技大學
【學位級別】：碩士
【學位授予年份】：2017
【分類號】：TG142.71;TG337.5
[Abstract]:The austenitic stainless steel is widely used in the fields of food, chemical industry and the like due to the excellent toughness, high temperature oxidation resistance, corrosion resistance and the like, but the strength of the solid soluble austenitic stainless steel is low, so that the austenitic stainless steel is rarely used as a structural material, it is often necessary to improve its comprehensive performance by means of a cold rolling to meet its use requirements, cold rolling as an efficient cold rolling method, and often used as a means of improving the performance of the stainless steel. In recent years, there are many studies on the effect of cold rolling on the properties of austenitic stainless steel at room temperature, but few have systematically studied the effect of cold rolling and cryogenic rolling on the microstructure and properties of 316LN austenitic stainless steel. And the object of cryogenic rolling research both at home and abroad is also limited to non-ferrous metals. In view of the above situation, this paper will comprehensively study the effect of cold rolling deformation on microstructure and properties of 316LN austenitic stainless steel, and provide experimental basis and technical support for the development and application of 316LN austenitic stainless steel. In this paper, 316 LN austenitic stainless steel was used as the research object, then the rolling at room temperature and cryogenic state (liquid nitrogen) were carried out respectively, and the mechanical properties of 316L austenitic stainless steel after rolling were studied in detail. The microstructure evolution of austenitic stainless steel is characterized by means of microstructure analysis such as transmission electron microscope (TEM). The results show that the deformation induced martensite transformation in the process of rolling deformation of austenitic stainless steel, and with the increase of rolling deformation, The larger the volume fraction of the deformation-induced martensite. In the condition of room temperature rolling, the volume fraction of deformation-induced martensite increased from 11.1% (30%) to 72.3% (90%). In the state of cryogenic rolling, when the rolling deformation amount is 30%, the volume fraction of deformation-induced martensite is 58. 7%, and when the deformation amount is 50%, its volume fraction is 77.8%, and when the rolling deformation continues to increase to 70%, the austenite structure has completely transformed into martensite. The comparison between the deformation amounts in the same rolling state and the comparison of different deformation amounts in two different rolling states shows that the rate of deformation induced martensite transformation in deep cooling rolling state is much higher than that of the room temperature rolling state, and the austenite structure can be converted into martensite by 100% under the deep cooling rolling state. In the process of rolling at room temperature, under the condition that the deformation amount is small, the deformation is mainly caused by the propagation and entanglement of dislocations, and at the same time, a small amount of the deformed columnar crystal and the lath martensite are generated, and when the deformation amount is large, the deformation structure mainly takes the deformed columnar crystal as the main structure, It is accompanied by a small number of high density dislocation walls and dislocation cells, and deformation induces a great deal of martensite. In the process of deep cooling, a large number of deformation-induced martensite has occurred during low deformation. When the deformation amount is further increased to 70%, the deformation-induced martensite transformation is completely induced inside the structure. With the increase of the deformation amount, the hardness value and the strength value of the austenitic stainless steel are also increased, the early stage is in a rapidly rising state, the later stage gradually becomes stable, and the same deformation amount, the hardness value and the strength value of the austenitic stainless steel after the deep cooling rolling are obviously higher than that of the room temperature cold rolling: When the deformation amount is 90%, the hardness value of the austenitic stainless steel after the deep cooling rolling is about 3 times of the original sample, the yield strength and the tensile strength are about 7 times and 3 times of the original sample, the hardness value of the sample after cold rolling at room temperature is about 2.6 times of the original sample, Yield strength and tensile strength were 4. 9 and 2. 2 times the original sample. The tensile fracture morphology of specimen was changed from ductile fracture to ductile fracture and quasi-cleavage mixed fracture. The elongation of the specimen decreases rapidly with the increase of rolling deformation and the change trend of mechanical property index is opposite: the elongation of the specimen decreases from 3.5% (30%) to 2.5% (90%) when rolling at room temperature. The elongation of cryogenic rolling decreases from 2.3% (30%) to 1.5% (90%).
【學位授予單位】：河南科技大學
【學位級別】：碩士
【學位授予年份】：2017
【分類號】：TG142.71;TG337.5
【參考文獻】
相關(guān)期刊論文 前10條
1 史金濤;侯隴剛;左錦榮;盧林;崔華;張濟山;;304奧氏體不銹鋼超低溫軋制變形誘發(fā)馬氏體轉(zhuǎn)變的定量分析及組織表征[J];金屬學報;2016年08期
2 秦小才;熊毅;任鳳章;高廣東;劉治軍;;不同溫度變形量對AISI310S不銹鋼組織和性能的影響[J];河南科技大學學報(自然科學版);2016年04期
3 許久凌;黃海威;趙明純;王鎮(zhèn)波;盧柯;;316L不銹鋼在表面機械滾壓處理時的形變誘導馬氏體相變和組織細化過程[J];材料研究學報;2016年01期
4 李鵬燕;熊毅;陳路飛;任鳳章;王曉國;;深冷軋制對AISI 310S不銹鋼組織和性能的影響[J];材料熱處理學報;2015年03期
5 裴海祥;曾莉;王立新;張海龍;王西濤;;316LN高氮超低碳奧氏體不銹鋼的熱變形行為和組織演變[J];特殊鋼;2014年06期
6 裴文嬌;郭訓忠;王文濤;陶杰;;316L奧氏體不銹鋼的高溫流變行為[J];塑性工程學報;2014年03期
7 ;Effect of Cold Rolling on Microstructure and Mechanical Properties of AISI 301LN Metastable Austenitic Stainless Steels[J];Journal of Iron and Steel Research(International);2012年10期
8 周翠蘭;劉紅梅;白晉鋼;聶志水;周禾豐;喬s，
本文編號：2312434
本文鏈接：http://sikaile.net/kejilunwen/jiagonggongyi/2312434.html
最近更新
教材專著
