CARTECH 201 MODIFIED

CarTech 201 Modified is a nitrogen-strengthened, chromium-manganese-nickel, austenitic stainless steel that provides substantially higher yield and tensile strength than CarTech 304, and has general-corrosion resistance between that of CarTech 430 and CarTech 304. Compared with CarTech 201 (UNS S20100), CarTech 201 Modified has a lower nickel content, which results in higher-strength levels after cold working. This datasheet provides information on composition and physical properties. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: SS-1319. Producer or source: Carpenter Technology Corporation.

Bio-Physico-Chemical Response of Drought Tolerant Chickpeas to Nickel

Experiments were conducted to evaluate response of two genetically different drought tolerant varieties of Cicer arietinum L. namely PUSA 1103, Desi variety and PUSA 1105, Kabuli variety to the basal applications of nickel chloride doses viz; 0, 0.62, 3.12, 12.5, 62.5 and 125 µg g-1. Significant increase in the growth was observed at 0.62 and 3.12 µg g-1 nickel chloride doses. Addition of nickel dose above this level reduced the leaf area, plant growth, root length and yield of the plants. Fruiting stage showed more severe toxicity symptoms in comparison to the vegetative stages. Protein contents in seeds and chlorophyll contents along with nitrate reductase activity increased significantly in the leaves at the lower nickel doses. Peroxidase and superoxide-dismutase activities increased in a concomitant manner with increasing nickel concentrations. Increased concentrations of the soil applied nickel demonstrated an increase in the content of nickel higher in shoots also followed by roots. Accumulation of nickel and grain yield was higher in Desi chickpea variety PUSA 1103, indicating for its potential utilization in crop improvement strategies to breed new chickpea genotypes for nickel and drought resistance.

Comparison of Corrosion Resistance in Physiological Saline Solution of Two Austenitic Stainless Steels – 316LV and REX734

In this work two austenitic stainless steels, REX734 and 316LV were tested in terms of their microstructure and corrosion properties. The REX734 is a newer generation stainless steel, with modified chemical composition, in comparison to the 316LV grade. Potentiodynamic study of corrosion resistance was conducted in physiological saline solution (0.9% NaCl solution). In spite of the similarities of microstructure, grain size and phase structure in both materials, the corrosion tests revealed that the REX734, with lower nickel and higher nitrogen content, had better corrosion resistance than 316LV. Repassivation potential in the REX734 was almost six times higher than for the 316LV steel. Superior corrosion resistance of the REX734 steel was also confirmed by surface observations of both materials, since bigger and more densely distributed pits were detected in 316LV alloy.

LEANDUP 35N

LeanDup 35N is a dual phase austenitic-ferritic stainless steel that has the ability to become as important as 316L. It offers better corrosion resistance than 316L in many environments, yet has similar machinability to 316L and a reduced cost due to the much lower nickel and molybdenum levels. This datasheet provides information on composition, physical properties, elasticity, and tensile properties as well as fracture toughness. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: SS-1141. Producer or source: Schmolz + Bickenbach.

MOUNT BLOOMFIELD, PALAWAN, PHILIPPINES: FORESTS ON GREYWACKE AND SERPENTINIZED PERIDOTITE

The forest across a sharp boundary between greywacke and serpentinized peridotite is described from a site with seasonal rainfall on Palawan, Philippines. The forest on greywacke was of much larger stature (trees up to 26m) than that on the serpentinized peridotite (trees up to 18m). The tree (>10cm dbh) species richness was the same on both substrata with 38 species in one 0.16ha plot on each side of the boundary. There were many more individuals in the greywacke plot (149) than on the serpentinized peridotite (114). Floristically the plots were very different, with only one tree species, an unidentified Madhuca, occurring on both sides of the boundary. The soil over the greywacke was notably more acid, had lower Mg/Ca quotients, and much lower nickel concentrations than the soil over serpentinized peridotite.

Inhibition of Anaerobic Digestion Caused by Heavy Metals

The severity of heavy metal inhibition on anaerobic digestion is dependent on the metal species and their dissolved concentration in the digester. The general sequence of inhibition on anaerobic digestion of municipal sewage sludge was found with Ni > Cu > Cd > Cr > Pb. Metal immobilization affinity in the sludge followed the reverse sequence. Due to sulfide production during digestion high quantities of heavy metals are precipitating as highly insoluble sulfide salts. Nickel was immobilized to 94 % in the digester and indicated the most dramatic effect on anaerobic digestion. At a concentration of 250 to 300 g Ni m-3 toxicity occurred. Lower nickel concentrations resulted in reversible process inhibition. Copper up to 1000 g Cu m-3 caused reversible inhibition of acid producing, fermentative, and methanogenic bacteria. The time necessary for recovery of the process was dependent on the initial copper concentration in the digester. The organisms indicated capability of adaptation to copper. The copper uptake in the digester was 97 %. Cadmium inhibited digestion of sewage sludge up to approximately 50 % at 650 g Cd m-3. For long durations of acclimation a tendency toward recovery was observed. The cadmium uptake in the digested sludge was 99 %. Chromium and lead were uptaken at 99.9 % during digestion. Hence, the addition of these metals up to 1000 mg Cr/l and 600 mg Pb/l showed only little effect on anaerobic digestion.

Resistance to Pitting of Types 202 and 321 Steels to Sulfuric Acid and Sodium Chloride Solutions

Anodic potentiokinetic polarization measurements were made of pitting corrosion of two stainless steels in 1 N sulfuric acid and 1 N sodium chloride solutions to compare then-resistance to this type of corrosive attack. One steel was approximately of the same analyses as AISI Type 321 (H18N9), the second a substitutional steel with lower nickel content containing manganese and nitrogen approximately of the same analyses as AISI Type 202 (OH17N4G8). The steels were investigated both in as-cast state and after the plastic deformation. Type H18N9 steel, in its passive potential region is somewhat less resistant to pitting, assuming that total corrosion volume is taken into account-However, the type of pits seems to be more dangerous in Type OH17N4G8 steel. A similar situation is observed with respect to the structure effect. Rolled alloys exhibit greater total pitting corrosion losses while those tested as-cast suffers less extensive over-pitting. Pits in as-cast materials are, however, deeper and larger.

AISI 9840

AISI 9840 is a nickel-chromium-molybdenum steel very similar to AISI 4340 with lower nickel and slightly higher manganese. In the heat treated condition it has good combination of strength, fatigue resistance, toughness and wear resistance. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness. It also includes information on forming, heat treating, machining, and joining. Filing Code: SA-55. Producer or source: Alloy steel mills and foundries.