微量元素鋁和氮對(duì)SWRCH35K鋼淬火組織和淬透性的影響

微量元素鋁和氮對(duì)SWRCH35K鋼淬火組織和淬透性的影響Effect of Trace Elements Al and N on Quenching Microstructure and Hardenability of SWRCH35K Steel

采用轉(zhuǎn)爐冶煉-LF爐精煉-連鑄-控制軋制-控制冷卻工藝生產(chǎn)了不同鋁和氮含量（微量）的SWRCH35K鋼熱軋盤條，通過淬火試驗(yàn)和末端淬透性試驗(yàn)，研究了微量元素鋁和氮對(duì)其淬火組織和淬透性的影響。結(jié)果表明：淬火后SWRCH35K鋼的顯微組織均為馬氏體+屈氏體；當(dāng)鋼中鋁元素含量基本相同時(shí)，隨氮含量的增加，淬火后馬氏體含量減少，鋼的淬透性降低；氮含量基本相同時(shí)，鋁含量的增加導(dǎo)致鋼淬火后馬氏體含量減少，鋼的淬透性降低；鋁元素和氮元素生成的AlN或碳氮化物促進(jìn)晶粒細(xì)化，并作為非金屬夾雜物阻止淬火馬氏體的生成。

SWRCH35K hot-rolled wire rods with different content (microscale) of Al and N were produced by converter smelting-LF furnace refining-continuous casting-controlled rolling-controlled cooling process. The quenching microstructure and hardenability of SWRCH35K steel were investigated by quenching and Jominy test. The results show that the microstructure of SWRCH35K steel after quenching was martensite and troostite. Martensite content decreased with the increase of N content after quenching and the hardenability of steel degraded when Al content was almost the same. Martensite content decreased with the increase of Al content after quenching and the hardenability of steel degraded when N content was almost the same. AlN or carbonitride formed by Al and N elements promoted grain refinement and prevented the formation of martensite.