University of Science and Technology Beijing

Jinfeng Huang

Cheng Zhang

Jin Zhang

Chao Zhao

Jianqiang Li

Yong Lian

A low-carbon and low alloy hot-work die steel with a high toughness at low temperatures and a high strength at high temperatures and a high hardenability, comprises the following components: C: 0.15-0.35%, Si: 0.40-0.90%, Mn: ≤0.80%, Cr: 1.50-2.40%, Ni: 2.50-4.50%, Mo: 1.00-1.60%, V: 0.10-0.40%, W: 0.20-0.90%, P: ≤0.02%, S≤0.02%, and a balance of Fe matrix and other inevitable impurities. The above percentages are mass percentages. The material of the present invention can have a V notch impact energy of 30 J or more than 30 J at −40° C., a high temperature strength of 380 MPa or more at 700° C., and a hardenability of 200 mm or more to ensure the consistency of internal and external microstructures. The materials of the present invention can be applied to hot-work molds used in special working conditions that require high toughness at low temperatures, high strength at high temperatures and high hardenability.

Hot-work die steel with high toughness at low temperatures and high strength at high temperatures and high hardenability and preparation method thereof

The present application provides a low carbon martensitic high temperature strength steel and a preparation method thereof, wherein the chemical composition of the low carbon martensitic high temperature strength steel are: C: 0.10-0.25 wt %, Cr: 10.0-13.0 wt %, Ni: 2.0-3.2 wt %, Mo: 1.50-2.50 wt %, Si&#x2264;0.60 wt %, Mn&#x2264;0.60 wt %, W: 0.4-0.8 wt %, V: 0.1-0.5 wt %, Co: 0.3-0.6 wt %, Al: 0.3-1.0 wt %, Nb: 0.01-0.2 wt %, and a balance of Fe. The high temperature strength steel of the present application achieves high strength at high temperature by simultaneously precipitating both nano-coherent carbides and intermetallic compounds. It has an excellent toughness, and can be used for certain structural parts under special working conditions, such as aero-engines to increase its service life and service temperature.

Low carbon martensitic high temperature strength steel and preparation method thereof

The present application provides a hot-work die steel and a preparation method thereof wherein the chemical constituents of the hot-work die steel in mass percentage are as follows: C: 0.20-0.32 wt %, Si: &#x2264;0.5 wt %, Mn: &#x2264;0.5 wt %, Cr: 1.5-2.8 wt %, Mo: 1.5-2.5 wt %, W: 0.5-1.2 wt %, Ni: 0.5-1.6 wt %, V: 0.15-0.7 wt %, Nb: 0.01-0.1 wt %, and a balance of iron, wherein an alloying degree is 5-7%; a tensile strength of the hot-work die steel at 700&#xb0; C. is 560-700 MPa; a value of hardness of the hot-work die steel at room temperature is 32-38 HRC after holding at 700&#xb0; C. for 3-5 h; and the hot-work die steel has an elongation of 14% to 16% at room temperature, a percentage reduction of area of 48% to 65%, and an impact toughness of 52-63 J at room temperature. The hot-work die steel of the present application has an excellent thermal stability as well as a good plasticity and a toughness at room temperature.

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Beijing, China

Jinfeng Huang