SU1237719A1 - Casting steel - Google Patents

Description

The invention relates to metallurgy, namely, to cast high-strength, copper-free, heat-resistant, air-hardened, well welded steel, used in heavy-loaded sheet-welded structures.

The aim of the invention is to increase the hardenability in air, irossii, impact strength at negative temperatures, the improvement of weldability.

In tab. 1 shows the chemical composition of the investigated steels. Melting was carried out in laboratory induction furnaces IST-0.16 with a capacity of 150 kg,

Samples for chemical analysis were cast from steel of each heat, Kli Known steel

50-52 64-67 12.4-13.0 43-46

61-63 75-76 12.0-12 „5 40-43

377192

new samples for the study of mechanical properties, castings for the study of weldability.

In tab. 2 shows the mechanical properties of the steel after hardening heat treatment.

In tab. 3 shows the technological properties of welded joints, studied on rigid ring O samples.

As can be seen from the table. 2, the steel of the proposed composition possesses higher indicators of strength, ductility and impact toughness compared to the known steel.

. The selected alloying ensures the hardenability of steel in the air.

Table 1

Table 2

41.1-4.3 2.7-2.8

4.0-4.2 2.6-2.7

one

Hardening heat treatment mode

Yield point, kgf / mm

We offer steel

76-80 89-92 20-21

Double quenching in air from 950 and 900 ° С, tempering 560 ° С 79-83 92-94 17-19

5 Double hardening in air from 950 and 900 C,, tempering 560 ° С 85-90 99-104 14-16 46-51 4.5-6.0 3.3-5.0

Table 3

Melting Welding methodToughness The presence of hot

welded plate, cracks in the sample

kgf / mm

Known steel

A9No

1Welding in heat-treated

(

heated conditions

2Welding in thermohardened state without heating

We offer steel

7 No

3Welding in heat-treated -

unheated state ° 0

Compiled by S. Derkacheva. Editor M. Tsitkina. Techred V. Kadar Corrector G. Crosher

Order 3263/32 Circulation 567 Subscription

VNIIPI USSR State Committee

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

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

Continuation of table 2

Relative elongation

Z

Relative constriction

Shock "Vibration, kgf / cm, at a temperature, C

lO c

-so c

54-56 4.7-6.9 3.6-5.7

44-52 5.7-5.9 5.2-5.4

Claims (1)

CASTING STEEL containing carbon, manganese, silicon, chromium, nickel, molybdenum and iron, characterized in that, in order to increase hardenability in air, strength, toughness at low temperature, improve weldability, the steel additionally contains aluminum and calcium in the following ratio components, wt. X: Carbon 0.06-0.10 Manganese 0.8-1.2 Silicon 0.4-0.8 Chromium 1.8-2.7 Nickel 0.4-1.2 Molybdenum 0.2-0.3 Aluminum 0.01-0.06 Calcium 0.01-0.03 Iron Rest