• <cite id="txc8r"></cite>
      <u id="txc8r"><tr id="txc8r"></tr></u>
      欧洲精品色在线观看,毛片免费试看,久久99国产综合精品免费,99久久无色码中文字幕人妻蜜柚,亚洲成在人的天堂网址,奇米四色7777中文字幕,9lporm自拍视频区,亚洲综合日韩av在线
      西安不鏽鋼管,西安不鏽鋼板,西安不鏽鋼棒,西安304不鏽鋼管,西安304不鏽鋼板,西安316不鏽鋼,西安321不鏽鋼,西安2520不鏽鋼,西安不鏽鋼無縫管,西安鏽鋼加工,西安不鏽鋼焊管,西安不鏽鋼方管,西安不鏽鋼管件,西安304不鏽鋼板,西安316不鏽鋼管,西安316不鏽鋼板,西安2520不鏽鋼管,西安2520不鏽鋼板,西安不鏽鋼法蘭,西安不鏽鋼角鋼,陝西不鏽鋼管,陝西不鏽鋼板,
      文章詳情
      所在位置: 首頁> 技術(shù)諮詢>

      不鏽鋼焊接性能的主要表現(xiàn)

      日期:2025-12-17 14:34
      瀏覽次數(shù):0
      摘要:<span style="font-family:宋體;font-size:small;"> </span> <p style="margin:0cm 0cm 0pt;"> <span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;"><span style="font-size:small;">不鏽鋼焊接性能的主要表現(xiàn)</span></span> </p> <span style="font-family:宋體;font-size:small;"> </span> <p style="margin:0cm 0cm 0pt;"> <span style="font-size:small;"><span style="font-family:'Times New Roman';"><span lang="EN-US">(1)</span></span><span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">高溫裂紋</span></span> </p> <span style="font-family:宋體;font-size:small;"> </span> <p style="margin:0cm 0cm 0pt;"> <span style="font-size:small;"><span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">在這裡所說的高溫裂紋是指與焊接有關(guān)的裂紋。高溫裂紋可大致分為凝固裂紋、顯微裂紋、</span><span style="font-family:'Times New Roman';"><span lang="EN-US">HAZ(</span></span><span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">熱影響區(qū)</span><span style="font-family:'Times New Roman';"><span lang="EN-US">)</span></span><span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">裂紋和再加熱裂紋等。</span></span> </p> <span style="font-family:宋體;font-size:small;"> </span> <p style="margin:0cm 0cm 0pt;"> <span style="font-size:small;"><span style="font-family:'Times New Roman';"><span lang="EN-US">(2)</span></span><span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">低溫裂紋</span></span> </p> <span style="font-family:宋體;font-size:small;"> </span> <p style="margin:0cm 0cm 0pt;"> <span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;"><span style="font-size:small;">在馬氏體型不鏽鋼和部分具有馬氏體組織的鐵素體型不鏽鋼中有時(shí)會(huì)發(fā)生低溫裂紋。由於其產(chǎn)生的主要原因是氫擴(kuò)散、焊接接頭的約束程度以及其中的硬化組織,所以解決方法主要是在焊接過程中減少氫的擴(kuò)散,適宜地進(jìn)行預(yù)熱和焊後熱處理以及減輕約束</span></span><span style="font-family:'Times New Roman';font-size:small;"> </span><span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;"><span style="font-size:small;">程度。</span></span> </p> <span style="font-family:宋體;font-size:small;"> </span> <p style="margin:0cm 0cm 0pt;"> <span style="font-size:small;"><span style="font-family:'Times New Roman';"><span lang="EN-US">(3)</span></span><span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">焊接接頭的韌性</span></span> </p> <span style="font-family:宋體;font-size:small;"> </span> <p style="margin:0cm 0cm 0pt;"> <span style="font-size:small;"><span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">在奧氏體型不鏽鋼中為減輕高溫裂紋敏感性,在成分設(shè)計(jì)上通常使其中殘存有</span><span style="font-family:'Times New Roman';"><span lang="EN-US">5% -io%</span></span><span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">的鐵素體。但這些鐵素體的存在導(dǎo)致了低溫韌性的下降,在雙相不鏽鋼進(jìn)行焊接時(shí),焊接接頭區(qū)域的奧氏體量減少而對(duì)韌性產(chǎn)生影響。另外隨著其中鐵素體的增加,其韌性值有顯著下降的趨勢(shì)</span><span lang="EN-US"><span style="font-family:'Times New Roman';">.</span></span></span> </p> <span style="font-family:宋體;font-size:small;"> </span> <p style="margin:0cm 0cm 0pt;"> <span style="font-size:small;"><span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">已證實(shí)高純鐵素體型不鏽鋼的焊接接頭的韌性顯著下降的原因是由於混入碳,氮、氧的緣故。其中一些鋼的焊接接頭中的氧含量增加後生成了氯化物型夾雜,這些夾雜物成為裂紋發(fā)生源或裂紋傳播的途徑使得韌性下降</span><span style="font-family:'Times New Roman';"><span lang="EN-US">.</span></span><span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">而有一些鋼則是由於在保護(hù)氣體中混人了空氣,其中的氨含量增加在基體解理麵</span><span style="font-family:'Times New Roman';"><span lang="EN-US">{100}</span></span><span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">麵上產(chǎn)生板條狀</span><span style="font-family:'Times New Roman';"><span lang="EN-US">Cr2 N</span></span><span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">,基體變硬而使得韌性下降。</span></span> </p> <span style="font-family:宋體;font-size:small;"> </span> <p style="margin:0cm 0cm 0pt;"> <span style="font-size:small;"><span style="font-family:'Times New Roman';"><span lang="EN-US">(4)b</span></span><span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">相脆化</span></span> </p> <span style="font-family:宋體;font-size:small;"> </span> <p style="margin:0cm 0cm 0pt;"> <span style="font-size:small;"><span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">奧氏體型不鏽銅、鐵素體不鏽鋼和雙相不鏽鋼易發(fā)生</span><span style="font-family:'Times New Roman';"><span lang="EN-US">b</span></span><span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">相脆化,由於組織中析出了百分之幾的</span><span style="font-family:'Times New Roman';"><span lang="EN-US">b</span></span><span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">相,韌性顯著下降。</span><span style="font-family:'Times New Roman';"><span lang="EN-US">o</span></span><span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">相一般是在</span><span style="font-family:'Times New Roman';"><span lang="EN-US">600</span></span><span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">~</span><span style="font-family:'Times New Roman';"><span lang="EN-US">900</span></span><span style="font-family:宋體;mso-bidi-font-family:宋體;">℃</span><span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">範(fàn)圍內(nèi)析出,尤其在</span><span style="font-family:'Times New Roman';"><span lang="EN-US">750</span></span><span style="font-family:宋體;mso-bidi-font-family:宋體;">℃</span><span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">左右*易析出。作為防止</span><span style="font-family:'Times New Roman';"><span lang="EN-US">b</span></span><span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">相產(chǎn)生的預(yù)防型措,</span><span style="font-family:'Times New Roman';"><span lang="EN-US">.</span></span><span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">奧氏體型不鏽鋼中應(yīng)儘量減少鐵索體的含量。</span></span> </p> <span style="font-family:宋體;font-size:small;"> </span> <p style="margin:0cm 0cm 0pt;"> <span style="font-size:small;"><span style="font-family:'Times New Roman';"><span lang="EN-US">(5) 475</span></span><span style="font-family:宋體;mso-bidi-font-family:宋體;">℃</span><span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">脆化</span></span> </p> <span style="font-family:宋體;font-size:small;"> </span> <p style="margin:0cm 0cm 0pt;"> <span style="font-size:small;"><span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">鉻含量在</span><span style="font-family:'Times New Roman';"><span lang="EN-US">15. 5%</span></span><span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">以上的不鏽鋼,在</span><span style="font-family:'Times New Roman';"><span lang="EN-US">475</span></span><span style="font-family:宋體;mso-bidi-font-family:宋體;">℃</span><span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">附近</span><span style="font-family:'Times New Roman';"><span lang="EN-US">(370 -540</span></span><span style="font-family:宋體;mso-bidi-font-family:宋體;">℃</span><span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">,長時(shí)間受熱時(shí),常會(huì)出現(xiàn)鋼的強(qiáng)度升高,韌性性大幅度降低</span><span style="font-family:'Times New Roman';"><span lang="EN-US">.</span></span><span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">並且伴隨著耐蝕性的降低。由於這一現(xiàn)象多見於加熱溫度在</span><span style="font-family:'Times New Roman';"><span lang="EN-US">475</span></span><span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">。</span><span style="font-family:'Times New Roman';"><span lang="EN-US">(</span></span><span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">左右,因此被稱作</span><span style="font-family:'Times New Roman';"><span lang="EN-US">475</span></span><span style="font-family:宋體;mso-bidi-font-family:宋體;">℃</span><span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">脆性。</span></span> </p> <span style="font-family:宋體;font-size:small;"> </span> <p style="margin:0cm 0cm 0pt;"> <span style="font-size:small;"><span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">由於不鏽鋼的鉻含量大多在</span><span style="font-family:'Times New Roman';"><span lang="EN-US">15. 5%</span></span><span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">以上,焊接時(shí)的焊接熱也一定會(huì)經(jīng)過</span><span style="font-family:'Times New Roman';"><span lang="EN-US">370</span></span><span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">~</span><span style="font-family:'Times New Roman';"><span lang="EN-US">540</span></span><span style="font-family:宋體;mso-bidi-font-family:宋體;">℃</span><span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">這個(gè)區(qū)間,如果焊接時(shí)控製不當(dāng)</span><span style="font-family:'Times New Roman';"><span lang="EN-US">.</span></span><span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">在</span><span style="font-family:'Times New Roman';"><span lang="EN-US">370</span></span><span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">~</span><span style="font-family:'Times New Roman';"><span lang="EN-US">540</span></span><span style="font-family:宋體;mso-bidi-font-family:宋體;">℃</span><span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">這個(gè)區(qū)間停留時(shí)間過長,在一些鉻含量較高的馬氏體不鏽鋼奧氏體不鏽鋼、鐵素體不鏽鋼、雙相不鏽鋼以及沉澱硬化不鏽鋼都會(huì)出現(xiàn)</span><span style="font-family:'Times New Roman';"><span lang="EN-US">475</span></span><span style="font-family:宋體;mso-bidi-font-family:宋體;">℃</span><span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">脆化。係統(tǒng)的研究指出</span><span style="font-family:'Times New Roman';"><span lang="EN-US">475</span></span><span style="font-family:宋體;mso-bidi-font-family:宋體;">℃</span><span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">脆化處理後,鋼不僅有冷脆性,還有熱脆性</span><span style="font-family:'Times New Roman';"><span lang="EN-US">(800</span></span><span style="font-family:宋體;mso-bidi-font-family:宋體;">℃</span><span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">以下的衝擊韌性比未脆化低</span><span style="font-family:'Times New Roman';"><span lang="EN-US">)</span></span><span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">。脆化程度隨鉻量的增加而增大,鉻含量在</span><span style="font-family:'Times New Roman';"><span lang="EN-US">15. 5%</span></span><span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">以下</span><span style="font-family:'Times New Roman';"><span lang="EN-US">.</span></span><span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">則無脆化趨勢(shì)。碳含量在</span><span style="font-family:'Times New Roman';"><span lang="EN-US">0. 04%</span></span><span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">~</span><span style="font-family:'Times New Roman';"><span lang="EN-US">0. 28%</span></span><span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">範(fàn)圍內(nèi),脆化程度冇有明顯的區(qū)彆。</span></span> </p> <span style="font-family:宋體;font-size:small;"> </span> <p style="margin:0cm 0cm 0pt;"> <span style="font-size:small;"><span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">奧氏體和鐵素體型不鏽鋼的可焊性較好。馬氏體型不鏽鋼,可焊性差,但馬氏體型不鏽鋼中的低碳馬氏體不鏽鋼和低碳鉻一鎳一鉬係</span><span style="font-family:'Times New Roman';"><span lang="EN-US">(</span></span><span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">超級(jí)</span><span style="font-family:'Times New Roman';"><span lang="EN-US">)</span></span><span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">馬氏體不鏽鋼,在采取一定的工藝、技術(shù)措施後,還是可以獲得較為滿意的焊接效果</span></span> </p> <span style="font-family:宋體;font-size:small;"> </span>

      不鏽鋼焊接性能的主要表現(xiàn)

      (1)高溫裂紋

      在這裡所說的高溫裂紋是指與焊接有關(guān)的裂紋。高溫裂紋可大致分為凝固裂紋、顯微裂紋、HAZ(熱影響區(qū))裂紋和再加熱裂紋等。

      (2)低溫裂紋

      在馬氏體型不鏽鋼和部分具有馬氏體組織的鐵素體型不鏽鋼中有時(shí)會(huì)發(fā)生低溫裂紋。由於其產(chǎn)生的主要原因是氫擴(kuò)散、焊接接頭的約束程度以及其中的硬化組織,所以解決方法主要是在焊接過程中減少氫的擴(kuò)散,適宜地進(jìn)行預(yù)熱和焊後熱處理以及減輕約束 程度。

      (3)焊接接頭的韌性

      在奧氏體型不鏽鋼中為減輕高溫裂紋敏感性,在成分設(shè)計(jì)上通常使其中殘存有5% -io%的鐵素體。但這些鐵素體的存在導(dǎo)致了低溫韌性的下降,在雙相不鏽鋼進(jìn)行焊接時(shí),焊接接頭區(qū)域的奧氏體量減少而對(duì)韌性產(chǎn)生影響。另外隨著其中鐵素體的增加,其韌性值有顯著下降的趨勢(shì).

      已證實(shí)高純鐵素體型不鏽鋼的焊接接頭的韌性顯著下降的原因是由於混入碳,氮、氧的緣故。其中一些鋼的焊接接頭中的氧含量增加後生成了氯化物型夾雜,這些夾雜物成為裂紋發(fā)生源或裂紋傳播的途徑使得韌性下降.而有一些鋼則是由於在保護(hù)氣體中混人了空氣,其中的氨含量增加在基體解理麵{100}麵上產(chǎn)生板條狀Cr2 N,基體變硬而使得韌性下降。

      (4)b相脆化

      奧氏體型不鏽銅、鐵素體不鏽鋼和雙相不鏽鋼易發(fā)生b相脆化,由於組織中析出了百分之幾的b相,韌性顯著下降。o相一般是在600900範(fàn)圍內(nèi)析出,尤其在750左右*易析出。作為防止b相產(chǎn)生的預(yù)防型措,.奧氏體型不鏽鋼中應(yīng)儘量減少鐵索體的含量。

      (5) 475脆化

      鉻含量在15. 5%以上的不鏽鋼,在475附近(370 -540,長時(shí)間受熱時(shí),常會(huì)出現(xiàn)鋼的強(qiáng)度升高,韌性性大幅度降低.並且伴隨著耐蝕性的降低。由於這一現(xiàn)象多見於加熱溫度在475(左右,因此被稱作475脆性。

      由於不鏽鋼的鉻含量大多在15. 5%以上,焊接時(shí)的焊接熱也一定會(huì)經(jīng)過370540這個(gè)區(qū)間,如果焊接時(shí)控製不當(dāng).370540這個(gè)區(qū)間停留時(shí)間過長,在一些鉻含量較高的馬氏體不鏽鋼奧氏體不鏽鋼、鐵素體不鏽鋼、雙相不鏽鋼以及沉澱硬化不鏽鋼都會(huì)出現(xiàn)475脆化。係統(tǒng)的研究指出475脆化處理後,鋼不僅有冷脆性,還有熱脆性(800以下的衝擊韌性比未脆化低)。脆化程度隨鉻量的增加而增大,鉻含量在15. 5%以下.則無脆化趨勢(shì)。碳含量在0. 04%0. 28%範(fàn)圍內(nèi),脆化程度冇有明顯的區(qū)彆。

      奧氏體和鐵素體型不鏽鋼的可焊性較好。馬氏體型不鏽鋼,可焊性差,但馬氏體型不鏽鋼中的低碳馬氏體不鏽鋼和低碳鉻一鎳一鉬係(超級(jí))馬氏體不鏽鋼,在采取一定的工藝、技術(shù)措施後,還是可以獲得較為滿意的焊接效果

      陝公網(wǎng)安備 61010402000326號(hào)

      主站蜘蛛池模板: 欧美mv日韩mv国产mv网站 | 天天狠天天透天干天天怕 | 中文有码亚洲制服av片| 久久精品国产亚洲av品| 国产免费人成视频在线播放播| 国产毛片三区二区一区| 亚洲专区中文在线第一页| 国产超高清麻豆精品传媒麻豆精品| 少妇wwwb搡bbb搡bbb| 无码精品人妻一区二区三刘亦菲| 国产成人A在线观看网站站| 亚洲人成网站18禁止无码| 99ri精品视频在线观看播放| 亚洲精品乱码久久久久久蜜桃欧美 | 日本中文字幕一区二区在线观看| 久久精品人人槡人妻人人玩AV| 美女高潮黄又色高清视频免费| AV喷水高潮喷水在线观看COM| 国产男女猛烈无遮挡免费视频| 国产成人成人一区二区| 欧美老熟妇牲交| 亚洲自偷自偷在线成人网站传媒| 狠狠色狠狠色综合久久蜜芽| 91麻豆国产精品| 精品无人乱码高清在线观看| 91亚洲精品第一| 亚洲日本va一区二区sa| 国产97在线 | 中文| 野花香在线视频免费观看大全| 亚洲国产AV无码精品无广告| 国产在线精品一区二区夜色| 色狠狠色婷婷丁香五月| 亚洲午夜精品成人在线| 三年片免费观看大全国语| 99热这里只有精品2| 乱人伦中文无码视频在线观看| 亚洲色欲色欲欲www在线| 欧美伊人色综合久久天天| 成人影院视频免费观看| 丰满人妻熟妇乱又仑精品| 久久青草精品38国产免费|