Showing papers on "Maraging steel published in 1969"
01 Jan 1969
14 citations
18 Sep 1969
TL;DR: In this paper, the authors present information for material selection and design guidance by providing an analysis of the interactions between the metallurgical and mechanical parameters that contribute to the fracture resistance of plate products.
Abstract: : The yield strength range for steels from 180 to 210 ksi is currently covered by four weldable alloys of the following nominal chemical analysis: 18%Ni-8%Co-3%Mo maraging steel, 12%Ni-5%Cr-3%Mo maraging steel, 9%Ni-4%Co-0.20%C quenched and tempered (Q and T) steel, and 10%Ni-8%Co-2%Cr-1%Mo-0.10%C Q and T steel. Broad ranges of fracture resistance have been reported for these materials based on various fracture tests, and this report presents information for material selection and design guidance by providing an analysis of the interactions between the metallurgical and mechanical parameters that contribute to the fracture resistance of plate products. Definitions of the interaction between the metallurgical and the mechanical aspects are developed with the use of the Dynamic Tear (DT) test and the Ratio Analysis Diagram (RAD). (Author)
6 citations
TL;DR: The pre-cracked cantilever beam test is a sensitive means of evaluating the relative susceptibilities of different steels to stress-Induced failure in H2S-containing environments as discussed by the authors.
Abstract: The pre-cracked cantilever beam test is a sensitive means of evaluating the relative susceptibilities of different steels to stress-Induced failure in H2S-containing environments. This, test indicated that a 12Ni 5Cr.3Mo maragmg stee1 is considerably more resistant to stress-induced crackining than the low-alloy steels 0Ni 1Cr 2Mo and 2Ni 1Cr 3Mo. For low-alloy steels with no applied potential the failure appears to be caused predominantly by hydrogen embrittlement. Impressed anodic or cathodic potentials have no effect on the time to Failure of low-alloy steels where as a zone of immunity exists for maraging steel with Impressed potentials Within the approximate range −0·6 to −1·0 V. This suggests that the maraging steel is less susceptible to hydrogen embrittlement than the quenched and tempered low-alloy steels. Permeability studies indicate that stress-induced failure is related to the ability of the steel to transmit hydrogen and to the nature of hydrogen traps in the steel.
6 citations
Patent•
23 Sep 1969
TL;DR: In this paper, a coarse grained maraging steel is refined by first heating the steel to a temperature between 1,700 DEG and 1,900 DEG F and then cooling the heated steel to below that at which the martensite transformation is completed.
Abstract: Coarse grained maraging steel is refined by first heating the steel to a temperature between 1,700 DEG and 1,900 DEG F. and then cooling the heated steel to a temperature below that at which the martensite transformation is completed. A steel having a substantially uniform grain size of ASTM No. 7 is obtained when the heating and cooling steps are repeated a total of three times.
5 citations
TL;DR: In this article, it was shown that a metal which is brittle at ambient pressure may become ductile when a hydrostatic pressure is applied, i.e., the ductile-brittle transition temperature may be lowered.
5 citations
TL;DR: In this paper, the authors showed that the plastic deformation of maraging steel after quenching and low-temperature aging (375°C for 1 h) leads to an increase of the strength and reduction of the plasticity with increasing degrees of deformation.
Abstract: 1.
Plastic deformation of maraging steel after quenching and low-temperature aging (375°C for 1 h) leads to an increase of the strength and reduction of the plasticity with increasing degrees of plastic deformation.
2.
Increasing the degree of plastic deformation of 60% after aging at 475°C (30 min and 3 h) induces an additional increase in strength. However, increasing the degree of plastic deformation to 90% decreases the strength and reduces the plasticity slightly.
3.
The highest strength resulted from the following combined treatment: quenching, aging, plastic deformation, aging. In this case it is possible to increase the tensile strength to 270 kg/mm2.
4.
The use of preliminary low-temperature thermomechanical treatment with subsequent aging makes it possible to increase the strength to 220–240 kg/mm2.
4 citations
TL;DR: In this paper, the effect of titanium and aluminum on the mechanical properties of maraging steel was investigated and it was found that the addition of up to 0.5% Al also has a favorable effect on the impact toughness of the steel.
Abstract: 1.
The investigation of the effect of titanium and aluminum on the mechanical properties of maraging steel showed that these elements strengthen the steel. It was found that the addition of up to 0.5% Al also has a favorable effect on the impact toughness of the steel.
2.
Increasing the degree of preliminary plastic deformation has a negligible effect on the strengthening of the steel after aging but leads to considerable acceleration of the aging process.
3.
The variation of the resistivity and the lattice constant show, that strengthening of the steel in the later stages of aging is due to depletion of molybdenum from the solid solution and the formation of strengthening phases.
4.
With a relatively small addition of titanium to the steel the data on the resistivity and lattice constant do not make it possible to draw conclusions on the participation of this element in the structural changes during aging. The increase of the degree of strengthening during aging of the steel containing titanium indicates its participation in strengthening.
5.
Weakening of the steel at elevated temperatures involves an increase in the amount of residual austenite, formed in the reverse martensitic transformation. Only at very high aging temperatures is this process accompanied by partial solution of the hardening phases, which is indicated by the increase of the resistivity.
3 citations
01 Mar 1969
TL;DR: In this paper, a 300 grade maraging steel, 17-4 PH steel, A-286, Rene 41, and L-605 were subjected to ultrasonic vibration during aging.
Abstract: : Specimens of a 300 grade maraging steel, 17-4 PH steel, A-286, Rene 41, and L-605 were Subjected to ultrasonic vibration during aging Ultrasonic vibration increased the hardening rate but did not increase the maximum hardness above that of statically aged specimens The heat treating environment (which included sodium, chloride salts, and air) was found to influence the observed hardening rates of vibrated aged specimens
3 citations
2 citations
TL;DR: Nickel maraging steel polarization behavior in acidic solutions, noting corrosion potential dependence on pH as discussed by the authors, has been shown to be a magnet for steel polarization in acidity-sensitive materials.
Abstract: Nickel maraging steel polarization behavior in acidic solutions, noting corrosion potential dependence on pH
TL;DR: For the same strength of steel N18K8M5T with different titanium concentrations, tensile tests of smooth and notched samples showed no difference in ductility down to −100°C as discussed by the authors.
Abstract: 1.
Increasing the titanium content of maraging steels increases their strength and lowers the plasticity and ductility.
2.
For the same strength of steel N18K8M5T with different titanium concentrations the tensile tests of smooth and notched samples show no difference in ductility down to −100°C.
An advantage in plasticity and ductility for the steel with the lower titanium content appears only in impact and static bending tests of samples with different types of notches at room and negative temperatures.
3.
For the highest ductility the titanium content of maraging steels should be held to the minimum. The optimal titanium content for this class of steels should be determined from the strength requirements.
TL;DR: The addition of 3-4% Mo to steel of this type is necessary for strengthening, and especially for prevention of embrittlement during aging as discussed by the authors, and this steel has satisfactory plasticity and ductility in combination with fairly high strength (σb=160−170 kg/mm2).
Abstract: 1.
After the optimal heat treatment, maraging steel 12 Ni-8 Co-4 Mo-2 Mn has satisfactory plasticity and ductility in combination with fairly high strength (σb=160−170 kg/mm2). However, in comparison with 18 Ni-8 Co-5 Mo steel with the same strength, this steel is more susceptible to embrittlement.
2.
The addition of 3–4% Mo to steel of this type is necessary for strengthening, and especially for prevention of embrittlement during aging.