Hot Strength and Creep Resistance of a High Interstitial Austenitic CrMn Steel

Abstract

ÃThe hot strength and short-time creep resistance of austenitic steel CN0.85 with about (mass%) 18Cr, 18Mn, 0.6N, and 0.25C was investigated up to 7008C together with the corresponding structural changes of the solution annealed or cold worked initial states. In the primary creep range, the creep rate was rapidly reduced to the minimum creep rate and the more so after initial cold working. This also lowered the minimum creep rate but hardly the time to fracture. Precipitation of carbides and nitrides occurred in or near grain boundaries which gave rise to creep cracks. Precipitates within the grains, visible only in the overaged state, are assumed to have raised the resistance to creep. Comparing the creep strength of CN0.85 with standard hot work tool steel H11 points to an advantage of the former at service temperatures of >5508C. However, tests in practice are required to back up the favorable results of this tentative study.

Comparative Study of θ Projection Method and Its Modified Forms on Creep Life Prediction

“…[4] As the failure of structural components used under high-temperature conditions generally leads to fatal safety accident, creep life of the heatresistant steels needs to be predicted as precise as possible. [5][6][7] Numerous strategies have been proposed to predict the creep life of materials, among them the methods can be divided into two groups: one is mainly depended on the mathematical method with phenomenological characteristics and θ projection method is the typical one of this group. [8][9][10] Methods in the other group are mainly established based on the physical fracture process and they are referred as the continuum damage mechanics (CDM), [11] equations in these methods consider the microscopic deformation mechanism, and the parameters are trying to be assigned specific physic features.…”

“…[ 4 ] As the failure of structural components used under high‐temperature conditions generally leads to fatal safety accident, creep life of the heat‐resistant steels needs to be predicted as precise as possible. [ 5–7 ]…”

Austenite and forging effects on 18Cr-18Mn stainless steel impedance

“…8 Interstitial nitrides in steel can lead to increased cracking. 9 These chromium nitrides have high stability. 10 In this article we provide new information on 18Cr-18mn steel, including Bode diagrams, which indicate steel polarization resistance; this basic corrosion test has to date not been applied to 18Cr-18Mn steel.…”