SU1232701A1 - Foundry steel - Google Patents

Description

 12327012

The invention relates to metallurgy, plasticity and foundry lurgies, in particular, to the composition of foundry- ICBOHCTB steel. corrosion-resistant steel for casting parts of the Christmas tree and the column head of the oil equipment, working in corrosive environments at high pressures.

The purpose of the invention is to increase the strength, casting properties, corrosion resistance of steel.

The total content of aluminum, titanium and niobium in the proposed steel should not exceed 0.3 wt.%. Otherwise, an excessive amount of oxides, carbides (carbonitrides) and nitrides is formed, which concentrate in whole colonies on the grain boundaries and sharply reduce the entire level of corrosion resistance, etc. Tables 1 and 2 show the chemical composition, casting and mechanical properties, as well as the resistance to reduction of the proposed and weighted steels that underwent heat treatment under the following regime: hardening and tempering at 500-550 °.

The criterion for evaluating the corrosion resistance of steels to hydrogen sulfide cracking is the time in ki prototypes until the moment of their destruction.

ten

15

The test medium is a 3% solution of NaCI, covered with hydrogen sulfide to a concentration of 2550-3000 mg / l.

 .

shaft ,

10.55 0.38 0.87 19.4 7.9 2.7 1.8 0.14 0.93

Offer

2 3 4 5 6 7

0.040.83t, 3418,56,03,1 t, $ 0,120,01.0,020,010.04

0.020,200,3016,09,04,0.2,50,20О, t0,0050,030,0l

0,081,500,9622,08,32,0 1,00,050,050,030,050,10

0.070.921.5020.47.83.6 2.30.080.030.05 0.0010.07

-0,0190,191,53155,84,1 0,90,040,009090,060,060,009

+0.09 ", 550.2822.49.2J, 9 2.60.21O, If0.004Followers, It

aoischavme. Plap 6 tt 7 are predlt doping, and output for the proposed.

carry, ductility and foundry ICBOHCTB steel.

In tab. Tables 1 and 2 show the chemical composition, casting and mechanical 5 properties, as well as the resistance to cracking of the proposed and known steels that have undergone heat treatment in the following mode: quenching from 1100 and tempering at 500-550 0.

The criterion for evaluating the corrosion resistance of steels to hydrogen sulfide cracking is the time of quenching the test specimens until the moment of brittle fracture.

0

The test medium is a 3% solution of NaCI acidified with hydrogen sulphide to a concentration of 2550-3000 mg / l.

Table t

- The rest

to the same

and

. "

652

423 18.7 35

Compiled by B, Brostrëm Editor H, Gunko Tehred M. Hodgshich Proofreader M. Maksimishinei

Order 2739/28 Circulation 567 Subscription

VNIIPI USSR State Committee

for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5

Production and printing company, Uzhgorod, Projecto st., 4

table 2

930

187

320 2.31 855

Claims (1)

1. CASTING STEEL containing carbon, manganese, silicon chromium, nickel, molybdenum, copper, titanium, rare earth metals. And iron, characterized in that, in order to increase the strength and casting properties, as well as corrosion resistance, it is additionally contains aluminum, calcium and niobium in the following ratio of components, wt.%: Carbon 0.02-0.08 Manganese 0.2-1.5 Silicon 0.3-1.5 Chromium 16.0-22.0 Nickel 6.0-9.0 Molybdenum 2.0-4.0 Copper 1.0-2.5 Rare Earth Titanium 0.05-0.20 metals 0.01-0.1 Aluminum 0.005-0.05 ' Calcium 0.001-0.05 Niobium 0.01-0.1 (g Iron 2. Steel by Rest Clause 1, distinguish- ω i am with me that the total content from burning aluminum titanium and nio biya £ 0.3 wt.% • MA 232701 2 properties, ductility and casting properties of steel. In the table. Figures 1 and 2 show the chemical composition, casting and mechanical properties of 5, as well as the cracking resistance of the proposed and known steels that underwent heat treatment in the following mode: quenching from 11001150’s and tempering at 500-550 ^ 0. The criterion for assessing the corrosion resistance of steels to hydrogen sulfide cracking is the time of curing of the test specimens until brittle fracture. The test medium is a 3% NaCI solution, acidified with hydrogen sulfide to a concentration of 2550-3000 mg / L.