Effect of Forging Deformation and Cooling on Mechanical Properties of Martensitic Stainless Steel

Stainless steel has good mechanical properties compared to other materials for strength and hardness, usually it will increase in hardness after hardening or forging. The purpose of this study was to obtain information about: The value of hardness and tensile strength of martensitic stainless steel forging with various deformations and cooling. The research method used is an experimental method, namely by forging on martensitic stainless steel with variations in deformation and cooling rate. Variations of forging deformation used are 25%, 50%, and 75%. The cooling media used are water, oil and air. The results of forgings with various cooling media were tested for tensile strength and tested for hardness using the Rockwell C (HRC) method. It was found that the higher the value of forging deformation, the higher the value of strength and hardness of martensitic stainless steel. This is because more and more martensite structures are recrystallized. In addition, it was also found that water and air cooling media gave an increase in the hardness of martensitic stainless steels. This is influenced by the cooling rate, where the higher the cooling rate, the more martensite structures formed, thus increasing the hardness value. The increase in hardness value is proportional to the increase in yield strength and tensile strength.

Study on properties of 18MND5 steel forgings for PWR steam generator

In the pressurized water reactor (PWR) nuclear power plant, the shell material of steam generator is required to have good strength-toughness matching, anti-fatigue performance, and neutron radiation resistance to ensure the long-term safe and reliable service. The manufacturing requirements of Manganese-Nickel-Molybdenum alloy steel forgings of steam generator channel head for Hua-long Pressurized Reactor (HPR1000) and Advanced Passive PWR(AP1000) nuclear power plant were compared. The heat treatment process, chemical composition, mechanical properties, metallographic structure of 18MND5 steel forging and SA 508-III steel forging were analysed and studied. The results show that the performance heat treatment temperature of HPR1000 forging has more stringent controls and with lower element content of C, Mo, P, Si, V, Co than the AP1000 forging. By reducing the C content, HPR1000 forging got better toughness while the strength was ensured.

The Effect of Rare Earth Metals Alloying on the Internal Quality of Industrially Produced Heavy Steel Forgings

The paper presented the findings obtained by industrial research and experimental development on the use of rare earth metals (REMs) in the production of heavy steel ingots and their impact on the internal quality of the 42CrMo4 grade steel forging. REMs alloying was carried out after vacuuming the steel. A relatively large melting loss of cerium (about 50%) and its further decrease in casting due to reoxidation were observed. Refinement of structure and better mechanical properties of forged bar containing about 0.02 wt.% of Ce compared to that of the standard production were not achieved. The wind power shaft with content of about 0.06 wt.% of Ce showed high amount of REM inclusions, which were locally chained, and in some cases, initiated cracks. Four stoichiometrically different types of REM inclusions were detected in forgings, namely (La-Ce)2O2S + (La-Ce)O2 + SiO2 (minority); oxygen, phosphorus, arsenic, and antimony bound to lanthanum and cerium probably bonded with iron oxides La + Ce, MgO, Al2O3 a SiO2; (La-Ce)2O2S, FeO, SiO2, and CaO or CaS.

Failures Related to Hot Forming Processes

The primary purpose of this article is to describe general root causes of failure that are associated with wrought metals and metalworking. This includes a brief review of the discontinuities or imperfections that may be common sources of failure-inducing defects in the bulk working of wrought products. The article addresses the types of flaws or defects that can be introduced during the steel forging process itself, including defects originating in the ingot-casting process. Defects found in nonferrous forgings—titanium, aluminum, and copper and copper alloys—also are covered.

The Effect of Forging Conditions on Final Macrostructure of Slab Ingot from the 55NiCrMoV7 Tool Steel

The paper presents numerical modelling and an operational experiment to forge a slab ingot P40N from 55NiCrMoV7 tool steel and the procedure for the optimization of its production. The aim of the numerical simulation of forging was to verify the existing procedure of forging a plate from a conventional polygonal 8K forging ingot and a slab ingot with a polygonal shape of P40N surfaces. The effect of the shape of the ingot on the achievement of the required forging reduction and strain after the cross section of the forging of the plate, with final dimensions of approximately 1010 mm width × 310 mm thickness × 5350 mm length, was studied. The results obtained in the operational experiment showed satisfactory qualitative parameters of the steel forging from the slab P40N ingot which were in accordance with the predicted results of numerical simulations. The results indicated that in selected cases the use of a slab P40N ingot instead of the conventional polygonal 8K forging ingot can be considered in the production of certain plate-type forgings.

Study on Forging Permeability of 06Cr19Ni9NbN Steel during Hot Deformation

The hot compression tests of 06Cr19Ni9NbN steel were conducted at strains rate of 0.005-5s-1 and temperature of 900-1200 °C on Gleeble1500 thermal mechanical simulation tester. Based on stress-strain data, processing maps of the steel were established. According to the results of processing maps, the optimal process parameters of hot compression were obtained, which lies in the temperature range of 1000-1200°C and strain rate of 0.005-0.1s-1. And then, the process of plane strain compression of 06Cr19Ni9NbN steel was investigated and carried out at the temperature of 1000-1200 °C and reduction ratio of 10%-50%. After the hot compression tests, the room temperature tensile tests were carried out. The results indicated that the grain size and the mechanical properties gradually become stable when the reduction ratio increases to 30%, 34% and 40% at 1200 °C, 1100 °C and 1000 °C, respectively. Finally, a new model was presented to describe critical forging penetration efficiency, which is significant to optimize the steel forging process. Furthermore, the calculated results based on this new model were consistent with experimental results, indicating that the model is suitable to predict the critical FPE for the steel.

The origin of the word mazija ‘steel’

The word mazija ?steel; forging ingot; a kind of ordeal which required plucking red-hot iron from a cauldron of boiling water? is common in the western part of the Shtokavian dialect continuum. Its area includes the Zeta-Raska, the Eastern Herzegovinian and the Younger Ikavian dialect, the first of the Old Shtokavian and the other two of the Neo-Shtokavian type. There are no attestations of this word earlier than the first half of the 18th century. So far, it has been mainly believed to share a common origin with the homonymous mazija ?oak gall? from Turkish maz? id. This stance is hardly acceptable in view of the fact that not only the meanings of the two words but also their geographical distributions strongly diverge, mazija in the oak gall sense being limited to the Kosovo-Resava and Timok-Prizren dialect areas of southern Serbia. The comparison with French maz?e ?refined iron?, is even more doubtful, because this term has been attested only since 1824 and with no known etymology, The true origin of m?zija < maz?ja (gvozdja) should be sought in the late Greek (5th century AD) ????(?)? ??? ??????? ?iron mass shaped by a blacksmith?; the plural form ????? ??????? occurs in a Greek charter issued in 1347 by the Serbian tsar Dusan to the Great Lavra on Mt Athos. Curiously enough, in two Serbian founding charters of the same epoch there is a parallel passage where among other yearly incomes granted to the monastery iron ingots are mentioned, designated here by the gen. pl. nad'('), with complements gvozd(i)ja ?of iron? and m?r?nyh' ?of a standard weight?. The term is Slavic nada or nado, derivative from