大容積氣瓶用4130X鋼管橫向裂紋原因分析

Analysis of Causes for Transversal Crack of 4130X Steel Pipe for Making Large-volume Gas Cylinder

摘要: 為查明大容積氣瓶用4130X鋼管橫向裂紋的產(chǎn)生原因，對(duì)斷口進(jìn)行了宏觀和微觀分析，并分析了試樣的化學(xué)成分、力學(xué)性能、金相組織，發(fā)現(xiàn)該裂紋是由鋼瓶淬火時(shí)殘余應(yīng)力導(dǎo)致的淬火開(kāi)裂。鋼管外表面的磨削加工產(chǎn)生的磨痕在淬火時(shí)引起組織應(yīng)力集中是造成鋼瓶淬火開(kāi)裂的誘因。針對(duì)性地對(duì)鋼管生產(chǎn)工藝進(jìn)行優(yōu)化，通過(guò)酸洗去除氧化鐵皮，減徑拔制，有效避免了該問(wèn)題的再次發(fā)生。

Abstract: In order to find out the causes for the transversal crack of the 4130X steel pipe for making of the largevolume gas cylinder,the fracture surface is analyzed by means of both the macro and micro analyses,while the specimen is tested in terms of chemical composition,mechanical property and metallurgical structure.As a result,it is identified that the crack is a quenching-crack which is caused by the residual stress during quenching of the cylinder.When the pipe is being quenched,the milling scratch of it gets the stress concentrated,which acts as the incentive for the quench crack.Accordingly the steel pipe manufacture process is optimized with measures such as descaling the pipe with the pickling process and reduction drawing so as to avoid the re-occurrence of the problem.