固(gu)溶(rong)(rong)(rong)(rong)處(chu)理(li)是將合(he)金加熱(re)到高(gao)(gao)溫(wen)(wen)(wen)單－相區恒溫(wen)(wen)(wen)保(bao)持(chi)，使過(guo)(guo)(guo)剩相溶(rong)(rong)(rong)(rong)解(jie)到溶(rong)(rong)(rong)(rong)體(ti)(ti)(ti)后(hou)快速冷(leng)(leng)卻(que)、以(yi)得到過(guo)(guo)(guo)飽(bao)和(he)(he)固(gu)溶(rong)(rong)(rong)(rong)體(ti)(ti)(ti)的(de)(de)(de)(de)(de)(de)(de)熱(re)處(chu)理(li)工(gong)藝。首先，固(gu)溶(rong)(rong)(rong)(rong)處(chu)理(li)是為了溶(rong)(rong)(rong)(rong)解(jie)基(ji)體(ti)(ti)(ti)內碳(tan)化(hua)物、γ'相等(deng)以(yi)得到均勻(yun)的(de)(de)(de)(de)(de)(de)(de)過(guo)(guo)(guo)飽(bao)和(he)(he)固(gu)溶(rong)(rong)(rong)(rong)體(ti)(ti)(ti)，便于(yu)(yu)時效時重新析出(chu)顆粒(li)細小、分布均勻(yun)的(de)(de)(de)(de)(de)(de)(de)碳(tan)化(hua)物和(he)(he)γ'等(deng)強化(hua)相，同時消除由(you)于(yu)(yu)冷(leng)(leng)熱(re)加工(gong)產(chan)生(sheng)的(de)(de)(de)(de)(de)(de)(de)應力。使合(he)金發生(sheng)再結晶(jing)。其次，固(gu)溶(rong)(rong)(rong)(rong)處(chu)理(li)是為了獲(huo)得適宜(yi)的(de)(de)(de)(de)(de)(de)(de)晶(jing)粒(li)度(du)(du)(du)(du)(du)，以(yi)保(bao)證合(he)金高(gao)(gao)溫(wen)(wen)(wen)抗蠕變性(xing)能(neng)(neng)(neng)。固(gu)溶(rong)(rong)(rong)(rong)處(chu)理(li)的(de)(de)(de)(de)(de)(de)(de)溫(wen)(wen)(wen)度(du)(du)(du)(du)(du)范圍為980~1250℃,主要根據各個合(he)金中相析出(chu)和(he)(he)溶(rong)(rong)(rong)(rong)解(jie)規律及使用(yong)要求(qiu)來選擇(ze)，以(yi)保(bao)證主要強化(hua)相必要的(de)(de)(de)(de)(de)(de)(de)析出(chu)條件和(he)(he)一定的(de)(de)(de)(de)(de)(de)(de)晶(jing)粒(li)度(du)(du)(du)(du)(du)。對于(yu)(yu)長期高(gao)(gao)溫(wen)(wen)(wen)使用(yong)的(de)(de)(de)(de)(de)(de)(de)合(he)金，要求(qiu)有(you)較好的(de)(de)(de)(de)(de)(de)(de)高(gao)(gao)溫(wen)(wen)(wen)持(chi)久和(he)(he)蠕變性(xing)能(neng)(neng)(neng)，應選擇(ze)較高(gao)(gao)的(de)(de)(de)(de)(de)(de)(de)固(gu)溶(rong)(rong)(rong)(rong)溫(wen)(wen)(wen)度(du)(du)(du)(du)(du)以(yi)獲(huo)得較大的(de)(de)(de)(de)(de)(de)(de)晶(jing)粒(li)度(du)(du)(du)(du)(du)；對于(yu)(yu)中溫(wen)(wen)(wen)使用(yong)并(bing)要求(qiu)較好的(de)(de)(de)(de)(de)(de)(de)室溫(wen)(wen)(wen)硬(ying)度(du)(du)(du)(du)(du)、屈服(fu)強度(du)(du)(du)(du)(du)、拉伸強度(du)(du)(du)(du)(du)、沖(chong)擊韌性(xing)和(he)(he)疲勞強度(du)(du)(du)(du)(du)的(de)(de)(de)(de)(de)(de)(de)合(he)金，可采用(yong)較低(di)(di)的(de)(de)(de)(de)(de)(de)(de)固(gu)溶(rong)(rong)(rong)(rong)溫(wen)(wen)(wen)度(du)(du)(du)(du)(du)，保(bao)證較小的(de)(de)(de)(de)(de)(de)(de)晶(jing)粒(li)度(du)(du)(du)(du)(du)。高(gao)(gao)溫(wen)(wen)(wen)固(gu)溶(rong)(rong)(rong)(rong)處(chu)理(li)時，各種析出(chu)相都逐(zhu)步溶(rong)(rong)(rong)(rong)解(jie)，同時晶(jing)粒(li)長大；低(di)(di)溫(wen)(wen)(wen)固(gu)溶(rong)(rong)(rong)(rong)處(chu)理(li)時，不(bu)僅有(you)主要強化(hua)相的(de)(de)(de)(de)(de)(de)(de)溶(rong)(rong)(rong)(rong)解(jie)，而且(qie)可能(neng)(neng)(neng)有(you)某些相的(de)(de)(de)(de)(de)(de)(de)析出(chu)。對于(yu)(yu)過(guo)(guo)(guo)飽(bao)和(he)(he)度(du)(du)(du)(du)(du)低(di)(di)的(de)(de)(de)(de)(de)(de)(de)合(he)金，通常選擇(ze)較快的(de)(de)(de)(de)(de)(de)(de)冷(leng)(leng)卻(que)速度(du)(du)(du)(du)(du)；對于(yu)(yu)過(guo)(guo)(guo)飽(bao)和(he)(he)度(du)(du)(du)(du)(du)高(gao)(gao)的(de)(de)(de)(de)(de)(de)(de)合(he)金，通常為空(kong)氣中冷(leng)(leng)卻(que)。

 對2205雙相不銹鋼進行不同溫度的固溶處理會導致2205雙(shuang)相不銹鋼兩相組織的改變，進而導致其性能的差異，圖3.1是在不同溫度下2205雙相不銹鋼固溶處理后的微觀組織。

  選取1000℃作(zuo)為(wei)(wei)最(zui)低(di)(di)固溶溫(wen)度，當熱處理(li)溫(wen)度低(di)(di)于950℃時，雙(shuang)相(xiang)(xiang)(xiang)(xiang)(xiang)不銹(xiu)鋼基體(ti)(ti)(ti)(ti)(ti)(ti)會(hui)析(xi)出雜質相(xiang)(xiang)(xiang)(xiang)(xiang)σ相(xiang)(xiang)(xiang)(xiang)(xiang)，σ相(xiang)(xiang)(xiang)(xiang)(xiang)作(zuo)為(wei)(wei)富(fu)含Cr、Mo的(de)硬脆相(xiang)(xiang)(xiang)(xiang)(xiang)，其存(cun)在(zai)降低(di)(di)雙(shuang)相(xiang)(xiang)(xiang)(xiang)(xiang)不銹(xiu)鋼的(de)耐蝕性(xing)能。圖3.1(a)為(wei)(wei)950℃的(de)微觀(guan)組織，。相(xiang)(xiang)(xiang)(xiang)(xiang)廣泛分布(bu)于鐵(tie)素(su)體(ti)(ti)(ti)(ti)(ti)(ti)／奧(ao)氏(shi)體(ti)(ti)(ti)(ti)(ti)(ti)晶(jing)(jing)界。當溫(wen)度達到1000℃時，σ相(xiang)(xiang)(xiang)(xiang)(xiang)會(hui)消(xiao)失(shi)，雙(shuang)相(xiang)(xiang)(xiang)(xiang)(xiang)不銹(xiu)鋼中只存(cun)在(zai)鐵(tie)素(su)體(ti)(ti)(ti)(ti)(ti)(ti)相(xiang)(xiang)(xiang)(xiang)(xiang)和奧(ao)氏(shi)體(ti)(ti)(ti)(ti)(ti)(ti)相(xiang)(xiang)(xiang)(xiang)(xiang)。圖3.1(b)~(f)中深色區為(wei)(wei)鐵(tie)素(su)體(ti)(ti)(ti)(ti)(ti)(ti)，淺色區為(wei)(wei)奧(ao)氏(shi)體(ti)(ti)(ti)(ti)(ti)(ti)。奧(ao)氏(shi)體(ti)(ti)(ti)(ti)(ti)(ti)以鐵(tie)素(su)體(ti)(ti)(ti)(ti)(ti)(ti)為(wei)(wei)基體(ti)(ti)(ti)(ti)(ti)(ti)，呈(cheng)帶狀或(huo)島狀分布(bu)于鐵(tie)素(su)體(ti)(ti)(ti)(ti)(ti)(ti)上。隨(sui)著(zhu)溫(wen)度的(de)升(sheng)高，奧(ao)氏(shi)體(ti)(ti)(ti)(ti)(ti)(ti)晶(jing)(jing)粒尺寸變(bian)大。

 利(li)用IAS圖像(xiang)(xiang)分析(xi)軟件測(ce)量(liang)并計(ji)算相比(bi)例，每個(ge)熱處理溫度(du)下(xia)的金相圖取8張(zhang)計(ji)算，求取平均(jun)值。表3.2給出了利(li)用IAS圖像(xiang)(xiang)分析(xi)軟件計(ji)算得到(dao)不(bu)同固(gu)(gu)溶(rong)溫度(du)溫度(du)下(xia)2205雙(shuang)相不(bu)銹鋼的相比(bi)例。1000℃時，鐵(tie)素體(ti)(ti)含(han)量(liang)為(wei)48.3%,隨著固(gu)(gu)溶(rong)溫度(du)的升高(gao)，鐵(tie)素體(ti)(ti)相含(han)量(liang)增加(jia)，奧(ao)氏(shi)(shi)體(ti)(ti)相含(han)量(liang)下(xia)降，直到(dao)1200℃時，鐵(tie)素體(ti)(ti)含(han)量(liang)達到(dao)62.3%,奧(ao)氏(shi)(shi)體(ti)(ti)含(han)量(liang)僅占37.7%.這種鐵(tie)素體(ti)(ti)與奧(ao)氏(shi)(shi)體(ti)(ti)隨固(gu)(gu)溶(rong)溫度(du)的變(bian)(bian)化(hua)規律前人的研究結果相一致。兩相比(bi)例的變(bian)(bian)化(hua)曲(qu)線如圖3.2所示，兩相與溫度(du)的關系呈線性變(bian)(bian)化(hua)。當(dang)固(gu)(gu)溶(rong)溫度(du)約為(wei)1040℃時，其相比(bi)例為(wei)1:1。

 因此在(zai)本實驗的6個固(gu)(gu)溶溫度(du)中，當固(gu)(gu)溶溫度(du)為1050℃時(shi)，雙(shuang)相不銹鋼(gang)相比例最接近1:1。

 采用顯微(wei)硬度儀壓(ya)頭為菱形(xing)壓(ya)頭，荷載F為4.8N,分別測出菱形(xing)的兩個直徑(jing)d1和d2,根據下(xia)式計算顯微(wei)硬度：

所(suo)(suo)有(you)固溶溫(wen)度試(shi)樣均(jun)測5個點(dian)，最后求取平均(jun)值(zhi)(zhi)為(wei)個固溶溫(wen)度下2205雙相不銹鋼的顯(xian)微(wei)(wei)硬(ying)度值(zhi)(zhi)。顯(xian)微(wei)(wei)硬(ying)度值(zhi)(zhi)如表3.3所(suo)(suo)列(lie)，顯(xian)微(wei)(wei)硬(ying)度隨(sui)固溶溫(wen)度的變化曲線如圖3.3所(suo)(suo)示(shi)。

  從圖3.3可知，2205雙相不銹鋼的顯微硬度先下降，后上升。這主要是由于當溫度為1000℃時，鐵素體相中間夾雜著小塊狀的二次奧氏體，當溫度達到1050℃后，二次奧氏體含量減少，組織均勻化程度提高，硬度減小。在此之后，隨著固溶溫度的增加，奧氏體含量減少，具有體心立方結構的奧氏體相屬于軟軔相，具有面心立方結構的鐵素體是強硬相，因此材料顯微硬度值又升高。同樣對2507雙相(xiang)不銹鋼進行不同溫度的固溶處理會導致2507雙相不銹鋼兩相組織的改變，進而導致其性能的差異，以下是2507雙相不銹鋼在不同溫度下固溶處理后的微觀組織。

  2507雙(shuang)相(xiang)(xiang)(xiang)(xiang)(xiang)不銹鋼(gang)(gang)分別在(zai)(zai)(zai)1000℃、1050℃、1100℃、1150℃、1200℃下固(gu)溶(rong)(rong)(rong)0.5h后水(shui)冷的金相(xiang)(xiang)(xiang)(xiang)(xiang)組織如圖(tu)(tu)(tu)3.4所示(shi)(shi)。從圖(tu)(tu)(tu)3.4可以清晰地得知(zhi)當(dang)(dang)固(gu)溶(rong)(rong)(rong)溫(wen)(wen)(wen)度(du)(du)為1000℃時鐵(tie)素體相(xiang)(xiang)(xiang)(xiang)(xiang)與奧氏(shi)體相(xiang)(xiang)(xiang)(xiang)(xiang)兩相(xiang)(xiang)(xiang)(xiang)(xiang)相(xiang)(xiang)(xiang)(xiang)(xiang)界處(chu)(chu)有σ相(xiang)(xiang)(xiang)(xiang)(xiang)析出(chu)，隨固(gu)溶(rong)(rong)(rong)處(chu)(chu)理溫(wen)(wen)(wen)度(du)(du)升高(gao)到1050℃時σ相(xiang)(xiang)(xiang)(xiang)(xiang)已經溶(rong)(rong)(rong)解。利(li)用Image-Pro-Plus 圖(tu)(tu)(tu)像分析儀(yi)軟(ruan)件6.0版測(ce)定的相(xiang)(xiang)(xiang)(xiang)(xiang)比例如圖(tu)(tu)(tu)3.5所示(shi)(shi)。從圖(tu)(tu)(tu)3.5能夠獲得固(gu)溶(rong)(rong)(rong)熱處(chu)(chu)理溫(wen)(wen)(wen)度(du)(du)的增(zeng)高(gao)會(hui)導致(zhi)(zhi)σ析出(chu)相(xiang)(xiang)(xiang)(xiang)(xiang)含量降(jiang)低(di)，當(dang)(dang)固(gu)溶(rong)(rong)(rong)熱處(chu)(chu)理溫(wen)(wen)(wen)度(du)(du)大(da)于1050℃時σ相(xiang)(xiang)(xiang)(xiang)(xiang)已經完全溶(rong)(rong)(rong)解。這是由于固(gu)溶(rong)(rong)(rong)熱處(chu)(chu)理溫(wen)(wen)(wen)度(du)(du)的升高(gao)使鋼(gang)(gang)中(zhong)(zhong)鐵(tie)素體α相(xiang)(xiang)(xiang)(xiang)(xiang)量增(zeng)多，導致(zhi)(zhi)σ相(xiang)(xiang)(xiang)(xiang)(xiang)形成元素Cr和Mo在(zai)(zai)(zai)鐵(tie)素體相(xiang)(xiang)(xiang)(xiang)(xiang)中(zhong)(zhong)的濃度(du)(du)降(jiang)低(di)，進而導致(zhi)(zhi)當(dang)(dang)固(gu)溶(rong)(rong)(rong)熱處(chu)(chu)理溫(wen)(wen)(wen)度(du)(du)大(da)于1050℃時σ相(xiang)(xiang)(xiang)(xiang)(xiang)的形成受到抑制(zhi)。考慮到σ相(xiang)(xiang)(xiang)(xiang)(xiang)硬且脆，能夠大(da)幅度(du)(du)減弱材(cai)料的塑性與韌性，并且σ相(xiang)(xiang)(xiang)(xiang)(xiang)富Cr,很容(rong)易在(zai)(zai)(zai)其周(zhou)圍(wei)產生貧Cr區降(jiang)低(di)DSS2507的抗(kang)腐(fu)蝕性能，所以σ相(xiang)(xiang)(xiang)(xiang)(xiang)為DSS2507析出(chu)相(xiang)(xiang)(xiang)(xiang)(xiang)中(zhong)(zhong)危害最大(da)的相(xiang)(xiang)(xiang)(xiang)(xiang)，因(yin)此(ci)，在(zai)(zai)(zai)實際應用過(guo)程(cheng)中(zhong)(zhong)要想將(jiang)2507雙(shuang)相(xiang)(xiang)(xiang)(xiang)(xiang)不銹鋼(gang)(gang)中(zhong)(zhong)的熱軋態σ相(xiang)(xiang)(xiang)(xiang)(xiang)完全消除所選用的固(gu)溶(rong)(rong)(rong)溫(wen)(wen)(wen)度(du)(du)要不低(di)于1050℃。

  圖(tu)3.4中深色組織是(shi)鐵(tie)素體(ti)(ti)(ti)(ti)(ti)α相(xiang)、淺色組織是(shi)奧(ao)(ao)氏(shi)(shi)體(ti)(ti)(ti)(ti)(ti)γ相(xiang)。從圖(tu)3.4可知(zhi)奧(ao)(ao)氏(shi)(shi)體(ti)(ti)(ti)(ti)(ti)γ相(xiang)首先表(biao)現為(wei)長條狀，隨(sui)著固(gu)(gu)(gu)溶(rong)(rong)(rong)處理溫(wen)(wen)(wen)(wen)(wen)度(du)(du)(du)的(de)(de)(de)(de)升(sheng)高(gao)(gao)(gao)而(er)逐(zhu)漸變短，變成(cheng)島狀分(fen)布在(zai)基(ji)體(ti)(ti)(ti)(ti)(ti)鐵(tie)素體(ti)(ti)(ti)(ti)(ti)上(shang)面。從圖(tu)3.5及表(biao)3.4中給出(chu)的(de)(de)(de)(de)相(xiang)比(bi)例測量結果能夠(gou)獲得(de)鋼(gang)中鐵(tie)素體(ti)(ti)(ti)(ti)(ti)α相(xiang)量隨(sui)固(gu)(gu)(gu)溶(rong)(rong)(rong)熱(re)處理溫(wen)(wen)(wen)(wen)(wen)度(du)(du)(du)的(de)(de)(de)(de)升(sheng)高(gao)(gao)(gao)而(er)上(shang)升(sheng)，奧(ao)(ao)氏(shi)(shi)體(ti)(ti)(ti)(ti)(ti)γ相(xiang)體(ti)(ti)(ti)(ti)(ti)積(ji)分(fen)數隨(sui)著固(gu)(gu)(gu)溶(rong)(rong)(rong)溫(wen)(wen)(wen)(wen)(wen)度(du)(du)(du)的(de)(de)(de)(de)上(shang)升(sheng)而(er)下降(jiang)，這(zhe)是(shi)由于在(zai)較(jiao)高(gao)(gao)(gao)的(de)(de)(de)(de)固(gu)(gu)(gu)溶(rong)(rong)(rong)溫(wen)(wen)(wen)(wen)(wen)度(du)(du)(du)下2507雙相(xiang)不銹(xiu)鋼(gang)呈現出(chu)的(de)(de)(de)(de)組織為(wei)單一的(de)(de)(de)(de)鐵(tie)素體(ti)(ti)(ti)(ti)(ti)，隨(sui)固(gu)(gu)(gu)溶(rong)(rong)(rong)熱(re)處理溫(wen)(wen)(wen)(wen)(wen)度(du)(du)(du)的(de)(de)(de)(de)降(jiang)低(di)鐵(tie)素體(ti)(ti)(ti)(ti)(ti)逐(zhu)步轉(zhuan)(zhuan)化為(wei)奧(ao)(ao)氏(shi)(shi)體(ti)(ti)(ti)(ti)(ti)組織，即(ji)固(gu)(gu)(gu)溶(rong)(rong)(rong)熱(re)處理溫(wen)(wen)(wen)(wen)(wen)度(du)(du)(du)的(de)(de)(de)(de)升(sheng)高(gao)(gao)(gao)導致奧(ao)(ao)氏(shi)(shi)體(ti)(ti)(ti)(ti)(ti)逐(zhu)漸轉(zhuan)(zhuan)變為(wei)鐵(tie)素體(ti)(ti)(ti)(ti)(ti)組織。從圖(tu)3.5可以看出(chu)當固(gu)(gu)(gu)溶(rong)(rong)(rong)熱(re)處理溫(wen)(wen)(wen)(wen)(wen)度(du)(du)(du)在(zai)1000~1050℃之間時奧(ao)(ao)氏(shi)(shi)體(ti)(ti)(ti)(ti)(ti)y相(xiang)比(bi)例減(jian)小的(de)(de)(de)(de)比(bi)較(jiao)緩慢(man)，隨(sui)固(gu)(gu)(gu)溶(rong)(rong)(rong)熱(re)處理溫(wen)(wen)(wen)(wen)(wen)度(du)(du)(du)的(de)(de)(de)(de)升(sheng)高(gao)(gao)(gao)奧(ao)(ao)氏(shi)(shi)體(ti)(ti)(ti)(ti)(ti)γ相(xiang)含量減(jian)少的(de)(de)(de)(de)趨勢加快，這(zhe)是(shi)因為(wei)2507雙相(xiang)不銹(xiu)鋼(gang)中的(de)(de)(de)(de)氮元素是(shi)奧(ao)(ao)氏(shi)(shi)體(ti)(ti)(ti)(ti)(ti)形成(cheng)元素，在(zai)較(jiao)低(di)固(gu)(gu)(gu)溶(rong)(rong)(rong)溫(wen)(wen)(wen)(wen)(wen)度(du)(du)(du)下抑制了奧(ao)(ao)氏(shi)(shi)體(ti)(ti)(ti)(ti)(ti)相(xiang)向(xiang)鐵(tie)素體(ti)(ti)(ti)(ti)(ti)相(xiang)的(de)(de)(de)(de)轉(zhuan)(zhuan)變，而(er)固(gu)(gu)(gu)溶(rong)(rong)(rong)熱(re)處理溫(wen)(wen)(wen)(wen)(wen)度(du)(du)(du)的(de)(de)(de)(de)升(sheng)高(gao)(gao)(gao)會(hui)使N元素穩定(ding)奧(ao)(ao)氏(shi)(shi)體(ti)(ti)(ti)(ti)(ti)相(xiang)的(de)(de)(de)(de)作用逐(zhu)漸減(jian)弱，進而(er)導致奧(ao)(ao)氏(shi)(shi)體(ti)(ti)(ti)(ti)(ti)γ相(xiang)向(xiang)鐵(tie)素體(ti)(ti)(ti)(ti)(ti)α相(xiang)轉(zhuan)(zhuan)變速度(du)(du)(du)加快。

 2507雙相(xiang)(xiang)(xiang)不(bu)銹鋼(gang)(gang)中的奧(ao)(ao)(ao)(ao)氏(shi)體(ti)相(xiang)(xiang)(xiang)和鐵(tie)素體(ti)相(xiang)(xiang)(xiang)這兩種(zhong)相(xiang)(xiang)(xiang)的相(xiang)(xiang)(xiang)比(bi)(bi)(bi)例(li)主要受固(gu)溶處理(li)(li)工藝以(yi)及自身化學(xue)成(cheng)分(fen)(fen)的影響(xiang)，當(dang)鋼(gang)(gang)的主要化學(xue)成(cheng)分(fen)(fen)確定(ding)時(shi)(shi)，則兩相(xiang)(xiang)(xiang)比(bi)(bi)(bi)例(li)與固(gu)溶處理(li)(li)制度(du)有著密(mi)切(qie)聯系(xi)。DSS2507的相(xiang)(xiang)(xiang)比(bi)(bi)(bi)例(li)又影響(xiang)著其自身的性(xing)能，其塑性(xing)隨著鐵(tie)素體(ti)含量(liang)的增(zeng)多而減(jian)弱、耐應(ying)力腐(fu)(fu)蝕破裂能力隨著奧(ao)(ao)(ao)(ao)氏(shi)體(ti)含量(liang)升高而減(jian)弱，進(jin)(jin)(jin)而認為當(dang)鐵(tie)素體(ti)α相(xiang)(xiang)(xiang)跟奧(ao)(ao)(ao)(ao)氏(shi)體(ti)γ相(xiang)(xiang)(xiang)這兩相(xiang)(xiang)(xiang)相(xiang)(xiang)(xiang)比(bi)(bi)(bi)例(li)接近1:1時(shi)(shi)雙相(xiang)(xiang)(xiang)不(bu)銹鋼(gang)(gang)的綜(zong)合(he)性(xing)能最(zui)佳，有較好的抗腐(fu)(fu)蝕能力以(yi)及較優(you)的力學(xue)性(xing)能。從圖3.5可(ke)知固(gu)溶熱處理(li)(li)溫度(du)在(zai)1050~1100℃之間時(shi)(shi)可(ke)以(yi)使鋼(gang)(gang)中的兩相(xiang)(xiang)(xiang)組織比(bi)(bi)(bi)例(li)達(da)到(dao)1:1,本實驗中所選(xuan)用的5種(zhong)固(gu)溶溫度(du)中1050℃時(shi)(shi)鐵(tie)素體(ti)α相(xiang)(xiang)(xiang)跟奧(ao)(ao)(ao)(ao)氏(shi)體(ti)γ相(xiang)(xiang)(xiang)比(bi)(bi)(bi)例(li)最(zui)接近1:1,進(jin)(jin)(jin)而可(ke)以(yi)認為選(xuan)擇較優(you)的固(gu)溶熱處理(li)(li)溫度(du)使DSS2507中的兩相(xiang)(xiang)(xiang)含量(liang)比(bi)(bi)(bi)例(li)達(da)到(dao)1:1是有可(ke)能的，在(zai)實際應(ying)用過(guo)程中為了使2507雙相(xiang)(xiang)(xiang)不(bu)銹鋼(gang)(gang)獲得較好的綜(zong)合(he)性(xing)能，進(jin)(jin)(jin)行固(gu)溶處理(li)(li)時(shi)(shi)選(xuan)取的固(gu)溶溫度(du)應(ying)該在(zai)1050~1100℃之間。

  2507雙(shuang)相(xiang)(xiang)不銹鋼(gang)(gang)(gang)分別(bie)在(zai)1000℃、1050℃、1100℃、1150℃、1200℃固溶(rong)0.5h后(hou)水冷(leng)的(de)(de)(de)(de)硬(ying)(ying)度(du)(du)(du)值如圖(tu)(tu)3.6所(suo)示。從圖(tu)(tu)3.6可知DSS2507的(de)(de)(de)(de)硬(ying)(ying)度(du)(du)(du)隨固溶(rong)處(chu)(chu)(chu)(chu)理(li)(li)(li)溫(wen)(wen)(wen)度(du)(du)(du)的(de)(de)(de)(de)升(sheng)(sheng)(sheng)(sheng)高(gao)先(xian)減(jian)小(xiao)后(hou)變大呈(cheng)曲線變化。在(zai)1000~1050℃溫(wen)(wen)(wen)度(du)(du)(du)范圍內鋼(gang)(gang)(gang)的(de)(de)(de)(de)硬(ying)(ying)度(du)(du)(du)隨固溶(rong)熱處(chu)(chu)(chu)(chu)理(li)(li)(li)溫(wen)(wen)(wen)度(du)(du)(du)的(de)(de)(de)(de)增(zeng)(zeng)高(gao)而(er)(er)逐漸(jian)(jian)(jian)減(jian)小(xiao)，1050~1200℃范圍內隨固溶(rong)熱處(chu)(chu)(chu)(chu)理(li)(li)(li)溫(wen)(wen)(wen)度(du)(du)(du)的(de)(de)(de)(de)上(shang)升(sheng)(sheng)(sheng)(sheng)硬(ying)(ying)度(du)(du)(du)又(you)漸(jian)(jian)(jian)漸(jian)(jian)(jian)變大，且1050℃時(shi)DSS2507的(de)(de)(de)(de)硬(ying)(ying)度(du)(du)(du)表現為最小(xiao)。從3.2.1節分析(xi)可知當固溶(rong)溫(wen)(wen)(wen)度(du)(du)(du)為1000℃時(shi)在(zai)鐵素(su)體(ti)(ti)(ti)和奧氏(shi)(shi)體(ti)(ti)(ti)相(xiang)(xiang)界(jie)處(chu)(chu)(chu)(chu)有σ相(xiang)(xiang)析(xi)出，σ相(xiang)(xiang)是(shi)一種硬(ying)(ying)而(er)(er)脆的(de)(de)(de)(de)相(xiang)(xiang)，能夠提(ti)高(gao)雙(shuang)相(xiang)(xiang)不銹鋼(gang)(gang)(gang)的(de)(de)(de)(de)硬(ying)(ying)度(du)(du)(du)值，所(suo)以1000℃下(xia)鋼(gang)(gang)(gang)有較高(gao)的(de)(de)(de)(de)硬(ying)(ying)度(du)(du)(du)，而(er)(er)σ相(xiang)(xiang)會隨固溶(rong)熱處(chu)(chu)(chu)(chu)理(li)(li)(li)溫(wen)(wen)(wen)度(du)(du)(du)的(de)(de)(de)(de)升(sheng)(sheng)(sheng)(sheng)高(gao)而(er)(er)漸(jian)(jian)(jian)漸(jian)(jian)(jian)溶(rong)解(jie)到(dao)基(ji)體(ti)(ti)(ti)中，DSS2507的(de)(de)(de)(de)硬(ying)(ying)度(du)(du)(du)有下(xia)降的(de)(de)(de)(de)趨勢(shi)；同(tong)時(shi)又(you)由(you)于固溶(rong)熱處(chu)(chu)(chu)(chu)理(li)(li)(li)溫(wen)(wen)(wen)度(du)(du)(du)的(de)(de)(de)(de)增(zeng)(zeng)高(gao)導致鋼(gang)(gang)(gang)中的(de)(de)(de)(de)鐵素(su)體(ti)(ti)(ti)相(xiang)(xiang)量增(zeng)(zeng)加而(er)(er)奧氏(shi)(shi)體(ti)(ti)(ti)相(xiang)(xiang)量降低(di)，在(zai)室溫(wen)(wen)(wen)下(xia)鐵素(su)體(ti)(ti)(ti)是(shi)體(ti)(ti)(ti)心立(li)方結(jie)構（bcc)奧氏(shi)(shi)體(ti)(ti)(ti)是(shi)面心立(li)方結(jie)構（fcc),前者硬(ying)(ying)度(du)(du)(du)要(yao)高(gao)于后(hou)者，因(yin)此在(zai)鐵素(su)體(ti)(ti)(ti)含量逐漸(jian)(jian)(jian)升(sheng)(sheng)(sheng)(sheng)高(gao)的(de)(de)(de)(de)情況下(xia)鋼(gang)(gang)(gang)的(de)(de)(de)(de)硬(ying)(ying)度(du)(du)(du)也逐漸(jian)(jian)(jian)升(sheng)(sheng)(sheng)(sheng)高(gao)，即隨著(zhu)固溶(rong)溫(wen)(wen)(wen)度(du)(du)(du)的(de)(de)(de)(de)升(sheng)(sheng)(sheng)(sheng)高(gao)2507 雙(shuang)相(xiang)(xiang)不銹鋼(gang)(gang)(gang)的(de)(de)(de)(de)硬(ying)(ying)度(du)(du)(du)呈(cheng)升(sheng)(sheng)(sheng)(sheng)高(gao)的(de)(de)(de)(de)趨勢(shi)。綜上(shang)所(suo)述(shu)，隨固溶(rong)溫(wen)(wen)(wen)度(du)(du)(du)從1000℃上(shang)升(sheng)(sheng)(sheng)(sheng)到(dao)1200℃,2507雙(shuang)相(xiang)(xiang)不銹鋼(gang)(gang)(gang)硬(ying)(ying)度(du)(du)(du)呈(cheng)先(xian)降低(di)后(hou)升(sheng)(sheng)(sheng)(sheng)高(gao)的(de)(de)(de)(de)變化趨勢(shi)。