SCR420JIS合金结构钢(铬钼钢)主要化学成份%:C:0.18-0.23SI:0.15-0.35MN:0.60-0.85P:<0.030S:<0.030CR:0.90-1.20NI:<0.25MO:0.15-0.30CU:<0.30镍铬钼合金结构钢SNCM220SNCM240SCNM415SNCM415SNCM420SNCM431SNCM439SNCM447SNCM616SNCM625SNCM630SNCM815等常用日本铬钢牌号:SCR415SCR420SCR430SCR435SCR440SR***45等常用铬钼合金结构钢:SCM415SCM418SCM420SCM430SCM435SCM440等)