Title: Process for heat treatment of malleable cast iron
Application Number: 86106729 Application Date: 1986.09.29
Publication Number: 1010271 Publication Date: 1987.04.09
Approval Pub. Date: Granted Pub. Date: 1990.01.24
International Classifi-cation: C21D5/14
Applicant(s) Name: Shaoshan Steel Plant, Xiangtan Address:
Inventor(s) Name: Deng Qiwen
Attorney & Agent: LU ZHONGTING
Abstract:
     This invention is applicable to ferrite and pearlite malleable cast iron. The improvement is that when a workpiece is heated from normal temp. to 920-980 deg.C, the existing temp. rise by continuous heating is substituted by the two consecutive heat preservation and heating stages of low and moderate temp. respectively. Thus, the number of graphite cores are increased, crystal grains become fine, and the comprehensive mechanical properties of casting are improved. The tensile strength of the pearlite malleable cast iron is not less than 715.4 N/m to the power 2 and its elongation is not less than 5%. The tensile strength of the ferrite malleable cast iron is not less than 421.4 N/m to the power 2, and its elongation is not less than 15%.
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