The measured chemical composition of the experimental material is obtained by chemical analysis method and meets The measured chemical composition of the experimental material is obtained by chemical analysis method and meets the requirements of GB / t1220-2007. It can be seen that the chemical composition of the experimental steel meets the design composition range.
The linear expansion (or contraction) – temperature curves of experimental steel under heating and cooling conditions were measured by dil805 dilatometer. The sample size is Φ 4x10mm3, surface polishing. The temperature of phase transition point is obtained by tangent method. The hardness test is carried out on 430svd Vickers hardness tester, the load is 200gf and the holding time is 10s. Metallography was eroded with 4% nitric acid alcohol solution, and its microstructure was observed by axioimagerm2m optical microscope.