日本机械结构用碳素钢管STKM11ASTKM12ASTKM12BSTKM12CSTKM13ASTKM13BSTKM13CSTKM14ASTKM14BSTKM14CSTKM15ASTKM15CSTKM16CSTKM17ASTKM17CSTKM18ASTKM18BSTKM18BSTKM18CSTKM19ASTKM19CSTKM20A韩国机械结构用合金钢管SCR420TKSCM415TKSCM418TKSCM420TKSCM430TKSCM435TKSCM440TK韩国保证淬透性结构钢SCR415HSCR420HSCR430HSCR435HSCR440HSN***15HSNC631HSNC815HSNCM220HSNCM420HSCM415HSCM418HSCM420HSCM435HSCM440HSCM445SCM822H***N420H***JN433H***N433H***N438H***N443H***N***20H***N***43H韩国保证淬透性结构钢旧钢号SCR21HSCR22HSCR2HSCR3HSCR4HSNC21HSNC2HSNC22HSNCM21HSNCM23HSCM21HSCM22HSCM3HSCM4HSCM5HSCM24H***N21H***N1H***N2H***N3H***NC21H***NC3H)