42crmo無縫鋼管的(de)(de)用(yong)(yong)途：　用(yong)(yong)于橋梁(liang)的(de)(de)專(zhuan)用(yong)(yong)鋼(gang)(gang)(gang)種為(wei)“42crmo”，汽車大梁(liang)的(de)(de)專(zhuan)用(yong)(yong)鋼(gang)(gang)(gang)種為(wei)“42CRmo”，壓(ya)力(li)容器的(de)(de)專(zhuan)用(yong)(yong)鋼(gang)(gang)(gang)種為(wei)“42Crmo”。 此(ci)(ci)類鋼(gang)(gang)(gang)是依靠調(diao)整(zheng)含(han)(han)碳(tan)(tan)(tan)(C)量來改善鋼(gang)(gang)(gang)的(de)(de)力(li)學性能，因此(ci)(ci)，根據含(han)(han)碳(tan)(tan)(tan)量的(de)(de)高低，此(ci)(ci)類鋼(gang)(gang)(gang)又可分為(wei)： 低碳(tan)(tan)(tan)鋼(gang)(gang)(gang)--含(han)(han)碳(tan)(tan)(tan)量一(yi)般(ban)小于0.25%，如10、20鋼(gang)(gang)(gang)等(deng); 中碳(tan)(tan)(tan)鋼(gang)(gang)(gang)--含(han)(han)碳(tan)(tan)(tan)量一(yi)般(ban)在0.25～0.60%之間(jian)，如35、45鋼(gang)(gang)(gang)等(deng); 高碳(tan)(tan)(tan)鋼(gang)(gang)(gang)--含(han)(han)碳(tan)(tan)(tan)量一(yi)般(ban)大于0.60%。此(ci)(ci)類鋼(gang)(gang)(gang)一(yi)般(ban)不(bu)用(yong)(yong)于制造鋼(gang)(gang)(gang)管。

　　根據標(biao)準GB/T 3077-1999,該鋼(gang)的化(hua)學成分(質量分數): Ni≤0.030%、P≤0.030%、S≤0.030%

　　42crmo為(wei)(wei)鋼材中的一(yi)種材質(zhi)。過(guo)去鋼材的一(yi)種叫法(fa)。稱法(fa)為(wei)(wei)：Q345B，與(yu)此相(xiang)近的材質(zhi)為(wei)(wei)Q345a，Q345c，Q345e，質(zhi)量(liang)等(deng)級符號A B C D E 分(fen)(fen)別表(biao)示不(bu)要(yao)(yao)求(qiu)沖(chong)(chong)擊(ji)(ji)試(shi)(shi)驗(yan)沖(chong)(chong)擊(ji)(ji)試(shi)(shi)驗(yan)溫度為(wei)(wei)+20度 0度 -20度 40度 　ABCD表(biao)示質(zhi)量(liang)等(deng)級 Q235質(zhi)量(liang)等(deng)級分(fen)(fen)為(wei)(wei)A、B、C、D四級，由A到(dao)D表(biao)示質(zhi)量(liang)由低到(dao)高。不(bu)同質(zhi)量(liang)等(deng)級要(yao)(yao)求(qiu)如下(xia)： A——提(ti)(ti)(ti)(ti)供(gong)(gong)(gong)S、P、C、Mn、Si化學成分(fen)(fen)和fu、fy、δ5(δ10)，根(gen)據買(mai)方需要(yao)(yao)可提(ti)(ti)(ti)(ti)供(gong)(gong)(gong)1800冷彎試(shi)(shi)驗(yan)，但(dan)無沖(chong)(chong)擊(ji)(ji)功(gong)(gong)規定，含(han)碳量(liang)和含(han)錳量(liang)不(bu)作為(wei)(wei)交貨條(tiao)件。 B——提(ti)(ti)(ti)(ti)供(gong)(gong)(gong)S、P、C、Mn、Si化學成分(fen)(fen)和fu、fy、δ5(δ10)，冷彎180‘試(shi)(shi)驗(yan)。還(huan)提(ti)(ti)(ti)(ti)供(gong)(gong)(gong)+200C時沖(chong)(chong)擊(ji)(ji)功(gong)(gong)Ak≥27J C——除與(yu)B級要(yao)(yao)求(qiu)一(yi)樣外(wai)，還(huan)提(ti)(ti)(ti)(ti)供(gong)(gong)(gong)00C時沖(chong)(chong)擊(ji)(ji)功(gong)(gong)Ak≥27J。 D----除與(yu)B級要(yao)(yao)求(qiu)一(yi)樣外(wai)，還(huan)提(ti)(ti)(ti)(ti)供(gong)(gong)(gong)-200C時沖(chong)(chong)擊(ji)(ji)功(gong)(gong)Ak≥27J E——除與(yu)B級要(yao)(yao)求(qiu)一(yi)樣外(wai)，還(huan)提(ti)(ti)(ti)(ti)供(gong)(gong)(gong)-400C時沖(chong)(chong)擊(ji)(ji)功(gong)(gong)Ak≥27J。