Regression Analysis of Chemical Composition and Properties of Low Alloy Steels

YANG Hongyu; SUN Qian; CHENG Xinli; SUN Yinglun; LIU Zhiguang; YUAN Qiangpeng

Abstract：Taking 420 MPa low alloys low temperature resistant steel plate samples with a thickness of 6 to 20 mm as the research object,a regression function between chemical composition and tensile properties was constructed using linear regression statistical analysis to address the actual issue of low tensile strength in a certain batch of such steel plates.The significance analysis was conducted to obtain the variation pattern.Based on this,adjusting the content of V,Cr,and Nb microalloy elements has greatly improved the strength and performance stability of this type of steel plate.The results show that P,V,Cr,Ni,etc.have a significant impact on the tensile properties of this type of steel plate.Taking into account the overall cost and smelting practice,the fine adjustment of the alloy process is as follows:remove V,increase Cr 0.1％-0.3％,increase Nb by 0.01％.After alloy optimization,the yield strength and tensile strength qualification rates of subsequent products are increased from 91.17％and 58.88％to 99.33％and 100％.The regression equation has good theoretical guidance significance for actual production.However,due to significant differences in the impact of multiple elements on performance and their interactions,the equation has certain limitations,such as introducing equation correction coefficients and correction functions,which have better guiding significance and still need to be continuously studied..