钢经渗碳后，钢表面层含碳量达到（ ）为佳。

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SQL Error: select id,body,options from ***_enewstiku where sourceid='24891' and id < 2124417 and id<>'2124417' order by id desc limit 5 SQL Error: select id,body,options from ***_enewstiku where sourceid='24891' and id > 2124417 and id<>'2124417' order by id asc limit 5