含碳量高的棒材發生過很多次斷裂,如45#鋼(gang)做(zuo)的(de)軸(zhou),使(shi)用(yong)不(bu)太(tai)長(chang)的(de)時(shi)間(jian)就(jiu)發(fa)生(sheng)斷(duan)裂(lie)。從(cong)斷(duan)裂(lie)後(hou)部(bu)件(jian)上(shang)取(qu)樣(yang),進(jin)行(xing)金(jin)相(xiang)分(fen)析(xi),往(wang)往(wang)找(zhao)不(bu)到(dao)產(chan)生(sheng)的(de)原(yuan)因(yin),即(ji)算(suan)牽(qian)強(qiang)附(fu)會(hui)找(zhao)到(dao)了(le)一(yi)些(xie)原(yuan)因(yin),也(ye)不(bu)是(shi)實(shi)際(ji)的(de)原(yuan)因(yin)。
weilequebaogenggaodeqiangdu,haibixuzaigangzhongtianjiatan,suizhijiuhuixichutietanhuawu。congdianhuaxuedeguandianlaikan,tietanhuawufahuileyinjizuoyong,jiakuailejitizhoubiandeyangjirongjiefanying。zaixianweizuzhineidetietanhuawutijifenshudezengdahaiguiyinyutanhuawudediqingchaodianyatexing。
鋼(gang)材(cai)表(biao)麵(mian)易(yi)於(yu)產(chan)生(sheng)並(bing)吸(xi)附(fu)氫(qing),氫(qing)原(yuan)子(zi)向(xiang)鋼(gang)材(cai)內(nei)部(bu)滲(shen)入(ru)的(de)同(tong)時(shi),氫(qing)的(de)體(ti)積(ji)分(fen)數(shu)就(jiu)可(ke)能(neng)會(hui)增(zeng)加(jia),最(zui)終(zhong)使(shi)得(de)材(cai)料(liao)的(de)抗(kang)氫(qing)脆(cui)性(xing)能(neng)顯(xian)著(zhu)降(jiang)低(di)。高(gao)強(qiang)鋼(gang)材(cai)耐(nai)腐(fu)蝕(shi)性(xing)和(he)抗(kang)氫(qing)脆(cui)性(xing)的(de)顯(xian)著(zhu)降(jiang)低(di)不(bu)僅(jin)有(you)害(hai)於(yu)鋼(gang)材(cai)的(de)性(xing)能(neng),還(hai)會(hui)極(ji)大(da)地(di)限(xian)製(zhi)鋼(gang)材(cai)的(de)應(ying)用(yong)。
如汽車用鋼暴露於氯化物等各種腐蝕環境中,在應力作用下,可能出現的應力腐蝕開裂(SCC)現象就會對車身的安全性造成嚴重的威脅。(2019年1月17日《中國冶金報》上鞍鋼副總經理王義棟說:攻關高強韌性無碳化物1380兆帕貝氏體鋼軌)
碳含量越高,氫擴散係數減小,氫溶解度增大。學者Chan曾經提出,析出物(作為氫原子的陷阱位置)、電位、空孔等各種晶格缺陷與碳含量成正比,碳含量增大,就會抑製氫擴散,因此氫擴散係數也較低。
youyutanhanliangyuqingrongjieduchengzhengbiguanxi,zuoweiqingyuanzixianjingdetanhuawu,tijifenshuyueda,gangcaineibudeqingkuosanxishuyuexiao,qingrongjieduzengda,qingrongjieduyebaohanleyouguankuosanxingqingdexinxi,yinerqingcuiminganxingzuigao。suizhetanhanliangdezengjia,qingyuanzidekuosanxishujianxiao,biaomianqingnongduzengda,zheshiyinweigangcaibiaomiandeqingchaodianyaxiajiangsuozhi。
從動電壓極化試驗結果來看,試樣的碳含量越高,酸性環境中就易於發生陰極還原反應(氫生成反應)以及陽極溶解反應。與具有低氫超電壓的周邊基體進行比較,碳化物發揮了陰極的作用,其體積分數增大。
根(gen)據(ju)電(dian)化(hua)學(xue)氫(qing)滲(shen)透(tou)試(shi)驗(yan)結(jie)果(guo),試(shi)樣(yang)內(nei)的(de)碳(tan)含(han)量(liang)和(he)碳(tan)化(hua)物(wu)的(de)體(ti)積(ji)分(fen)數(shu)越(yue)大(da),氫(qing)原(yuan)子(zi)的(de)擴(kuo)散(san)係(xi)數(shu)就(jiu)越(yue)小(xiao),溶(rong)解(jie)度(du)增(zeng)大(da)。隨(sui)著(zhe)碳(tan)含(han)量(liang)的(de)增(zeng)加(jia),抗(kang)氫(qing)脆(cui)性(xing)也(ye)會(hui)降(jiang)低(di)。
慢man應ying變bian速su率lv拉la伸shen試shi驗yan證zheng實shi,碳tan含han量liang越yue大da,抗kang應ying力li腐fu蝕shi開kai裂lie性xing能neng也ye會hui降jiang低di。與yu碳tan化hua物wu的de體ti積ji分fen數shu成cheng正zheng比bi,隨sui著zhe氫qing還hai原yuan反fan應ying及ji向xiang試shi樣yang內nei部bu滲shen透tou的de氫qing注zhu入ru量liang增zeng加jia,就jiu會hui發fa生sheng陽yang極ji溶rong解jie反fan應ying,也ye會hui加jia快kuai形xing成cheng滑hua移yi帶dai。
碳tan含han量liang的de增zeng大da,鋼gang材cai內nei部bu就jiu會hui析xi出chu碳tan化hua物wu,在zai電dian化hua學xue腐fu蝕shi反fan應ying的de作zuo用yong下xia,氫qing脆cui可ke能neng性xing就jiu會hui增zeng大da,為wei了le確que保bao鋼gang具ju備bei優you秀xiu的de耐nai腐fu蝕shi性xing和he抗kang氫qing脆cui性xing,對dui碳tan化hua物wu的de析xi出chu和he體ti積ji分fen數shu的de控kong製zhi進jin行xing是shi有you效xiao的de控kong製zhi方fang法fa。
gangcaizaiqichelingpeijianshangdeyingyongshoudaoyixiexianzhi,yeyaoguiyinyuqikangqingcuixingnengdemingxianxiajiang,erqingcuishiyoushuirongyefushichanshengde。shishishang,zhezhongqingcuiminganxingshiyutanhanliangmiqiexiangguande,zaidiqingchaodianyatiaojianxiaxichutietanhuawu(Fe2.4C / Fe3C)。
yibanzhenduiyinglifushikailiexianxianghuoqingcuixianxiangdaozhidebiaomianjubufushifanying,tongguorechulichuqucanyuyingli,zengdaqingxianjingxiaolvdengfangmiankaizhan。yaoxiangkaifajianjuyouxiunaifushixinghekangqingcuixingdechaogaoqiangqicheyonggang,yeziranbingfeiyishi。
隨(sui)著(zhe)碳(tan)含(han)量(liang)的(de)增(zeng)大(da),氫(qing)還(hai)原(yuan)速(su)率(lv)增(zeng)大(da),而(er)氫(qing)擴(kuo)散(san)速(su)率(lv)顯(xian)著(zhu)降(jiang)低(di)。使(shi)用(yong)中(zhong)碳(tan)或(huo)高(gao)碳(tan)鋼(gang)做(zuo)零(ling)部(bu)件(jian)或(huo)傳(chuan)動(dong)軸(zhou)等(deng),技(ji)術(shu)關(guan)鍵(jian)就(jiu)是(shi)對(dui)顯(xian)微(wei)組(zu)織(zhi)中(zhong)的(de)碳(tan)化(hua)物(wu)組(zu)分(fen)進(jin)行(xing)有(you)效(xiao)控(kong)製(zhi)。