江陰不銹鋼封頭的熱處理
時間: 2019-11-21 14:23:25來源: 宜興市恒安封頭有限公司
不銹鋼封頭在加熱和冷卻過程中,不銹鋼封頭由(you)于表層和(he)心(xin)部(bu)(bu)(bu)的冷(leng)卻(que)速(su)(su)度和(he)時間的不(bu)一致(zhi),形(xing)成(cheng)(cheng)溫(wen)差，就(jiu)會導致(zhi)體積(ji)膨脹(zhang)和(he)收縮不(bu)均(jun)而產(chan)生應力,即熱(re)(re)應力。在(zai)熱(re)(re)應力的作(zuo)(zuo)用(yong)下,由(you)于表層開始溫(wen)度低于心(xin)部(bu)(bu)(bu),收縮也大(da)于心(xin)部(bu)(bu)(bu)而使心(xin)部(bu)(bu)(bu)受(shou)拉(la)(la),當冷(leng)卻(que)結束時，由(you)于心(xin)部(bu)(bu)(bu)朂(xu)后冷(leng)卻(que)體積(ji)收縮不(bu)能(neng)自由(you)進行(xing)而使表層受(shou)壓(ya)心(xin)部(bu)(bu)(bu)受(shou)拉(la)(la)。即在(zai)熱(re)(re)應力的作(zuo)(zuo)用(yong)下朂(xu)終使工件表層受(shou)壓(ya)而心(xin)部(bu)(bu)(bu)受(shou)拉(la)(la)。這種現象(xiang)受(shou)到冷(leng)卻(que)速(su)(su)度,材(cai)料成(cheng)(cheng)分和(he)熱(re)(re)處(chu)理工藝等因素的影響。當冷(leng)卻(que)速(su)(su)度愈(yu)快(kuai),含碳(tan)量(liang)和(he)合金成(cheng)(cheng)分愈(yu)高(gao),冷(leng)卻(que)過程中在(zai)熱(re)(re)應力作(zuo)(zuo)用(yong)下產(chan)生的不(bu)均(jun)勻塑性變形(xing)愈(yu)大(da),朂(xu)后形(xing)成(cheng)(cheng)的殘(can)余應力就(jiu)愈(yu)大(da)。
另一(yi)(yi)方面(mian)鋼(gang)(gang)在(zai)熱處(chu)理(li)過(guo)程(cheng)中(zhong)由于(yu)組(zu)(zu)(zu)織(zhi)(zhi)(zhi)(zhi)(zhi)的(de)(de)變(bian)(bian)化(hua)即(ji)奧氏(shi)體(ti)向(xiang)馬氏(shi)體(ti)轉(zhuan)變(bian)(bian)時,因比容的(de)(de)增大(da)會伴隨工(gong)(gong)件(jian)(jian)(jian)體(ti)積(ji)的(de)(de)膨脹(zhang),工(gong)(gong)件(jian)(jian)(jian)各(ge)部(bu)位先后相(xiang)變(bian)(bian)，造(zao)成(cheng)體(ti)積(ji)長大(da)不一(yi)(yi)致(zhi)而產(chan)生組(zu)(zu)(zu)織(zhi)(zhi)(zhi)(zhi)(zhi)應(ying)(ying)力(li)(li)。不銹鋼(gang)(gang)封頭組(zu)(zu)(zu)織(zhi)(zhi)(zhi)(zhi)(zhi)應(ying)(ying)力(li)(li)變(bian)(bian)化(hua)的(de)(de)朂終結果(guo)是表(biao)層受(shou)(shou)(shou)拉應(ying)(ying)力(li)(li),心(xin)(xin)部(bu)受(shou)(shou)(shou)壓應(ying)(ying)力(li)(li),恰好(hao)與(yu)熱應(ying)(ying)力(li)(li)相(xiang)反。組(zu)(zu)(zu)織(zhi)(zhi)(zhi)(zhi)(zhi)應(ying)(ying)力(li)(li)的(de)(de)大(da)小與(yu)工(gong)(gong)件(jian)(jian)(jian)在(zai)馬氏(shi)體(ti)相(xiang)變(bian)(bian)區的(de)(de)冷(leng)卻(que)速度,形狀，材料(liao)的(de)(de)化(hua)學成(cheng)分(fen)等因素(su)有(you)(you)關(guan)。只不過(guo)熱應(ying)(ying)力(li)(li)在(zai)組(zu)(zu)(zu)織(zhi)(zhi)(zhi)(zhi)(zhi)轉(zhuan)變(bian)(bian)以(yi)前(qian)就(jiu)已(yi)經產(chan)生了不銹鋼(gang)(gang)封頭，而組(zu)(zu)(zu)織(zhi)(zhi)(zhi)(zhi)(zhi)應(ying)(ying)力(li)(li)則是在(zai)組(zu)(zu)(zu)織(zhi)(zhi)(zhi)(zhi)(zhi)轉(zhuan)變(bian)(bian)過(guo)程(cheng)中(zhong)產(chan)生的(de)(de),在(zai)整個冷(leng)卻(que)過(guo)程(cheng)中(zhong),熱應(ying)(ying)力(li)(li)與(yu)組(zu)(zu)(zu)織(zhi)(zhi)(zhi)(zhi)(zhi)應(ying)(ying)力(li)(li)綜合作(zuo)(zuo)用的(de)(de)結果(guo),就(jiu)是工(gong)(gong)件(jian)(jian)(jian)中(zhong)實際存在(zai)的(de)(de)應(ying)(ying)力(li)(li)。這兩(liang)種(zhong)應(ying)(ying)力(li)(li)綜合作(zuo)(zuo)用的(de)(de)結果(guo)是十(shi)分(fen)復雜(za)的(de)(de),受(shou)(shou)(shou)著(zhu)許(xu)多因素(su)的(de)(de)影響,如成(cheng)分(fen)、形狀、熱處(chu)理(li)工(gong)(gong)藝等。就(jiu)其(qi)發(fa)展過(guo)程(cheng)來(lai)說只有(you)(you)兩(liang)種(zhong)類型,即(ji)熱應(ying)(ying)力(li)(li)和組(zu)(zu)(zu)織(zhi)(zhi)(zhi)(zhi)(zhi)應(ying)(ying)力(li)(li),作(zuo)(zuo)用方向(xiang)相(xiang)反時二者抵消,作(zuo)(zuo)用方向(xiang)相(xiang)同(tong)時二者相(xiang)互(hu)(hu)(hu)迭加(jia)。不管是相(xiang)互(hu)(hu)(hu)抵消還是相(xiang)互(hu)(hu)(hu)迭加(jia),兩(liang)個應(ying)(ying)力(li)(li)應(ying)(ying)有(you)(you)一(yi)(yi)個占主導因素(su),熱應(ying)(ying)力(li)(li)占主導地位時的(de)(de)作(zuo)(zuo)用結果(guo)是工(gong)(gong)件(jian)(jian)(jian)心(xin)(xin)部(bu)受(shou)(shou)(shou)拉,表(biao)面(mian)受(shou)(shou)(shou)壓。組(zu)(zu)(zu)織(zhi)(zhi)(zhi)(zhi)(zhi)應(ying)(ying)力(li)(li)占主導地位時的(de)(de)作(zuo)(zuo)用結果(guo)是工(gong)(gong)件(jian)(jian)(jian)心(xin)(xin)部(bu)受(shou)(shou)(shou)壓表(biao)面(mian)受(shou)(shou)(shou)拉。
keyword:不銹鋼封頭
文章(zhang)來源：//hn-vesun.org.cn/
