Beijing Katherine Knott Steel Co., Ltd. 
 Cr12 alloy tool steel 
 Cr12 mold steel is steel, one of the representatives of the high carbon high chromium cold work die steel. Contains a high amount (mass fraction) C2.00% ~ 2.30% and Cr11.00% ~~ 13.00% are the ledeburite, so there is a high hardenability and hardenability and wear resistance, deformation hardening small, but when the carbide is not uniform, the deformation amount of multi-directional irregular, poor organization, its main drawback. Uneven carbide is difficult to heat treatment method to improve, unless they switch to the manufacture of powder metallurgy. Cr12 mold steel impact toughness, thermal conductivity and high temperature ductility is poor, and thermal processing to the attention of the heating and forging process. One of the cold work die steel in the mold steel is also common, but recently have been gradually more good steel the such as Cr12MoV, Cr12Mo1V1, or substrate steel replaced. The mold steel from the former Soviet Union X12 introduction, in 1957, already included in the standard (the YB-1957). Abroad, the same type of steel 210Cr12 (ISO), Japan SKD1 (JIS), Datong steel the DC1, the CRD of Hitachi Metals, Austria Bailu the K100, Sweden SVERER3 (UHB) and so on. Cr12 mold steel is used mainly for smaller impact load Die parts (punch die) requiring high wear, cold extrusion die of the die), has obvious advantages and disadvantages, use subject to certain restrictions. 
 Chemical composition: 
 Elements C, Si Mn Cr PS 
 Content of 2.00 to 2.30 ≤ 0.40 ≤ 0.40 11.50 ~ 13.00 ≤ 0.030 ≤ 0.030 
 Cr12 tempering: 
 Cr12 steel tempering specification recommended 
 Use heating temperature / ℃ tempering time / h tempering the number of hardness (HRC) 
 Eliminate the stress and stable organizations 
 Eliminate the stress and reduce the hardness of 180 ~ 200 
 320 ~ 3502 
 21 
 160 to 62 
 57 to 58 
 Cr12 quenched 
 Quenching temperature / ° C cooling medium hardness 
 950 980 Oil 59 63 
 Heat Treatment Specification: 
 Heat Treatment Specification: 1) quenching oil cooling, 950 to 1000 ℃; 2) quenched 980 ° C, cold oil, 180 ℃ tempering 2h. Microstructure: tempered martensite and undissolved carbides, retained austenite. Delivery status: delivery of steel in annealed condition.