CN105220074A - Chrome ferritic high temperature steel making method in a kind of boiler swing pipe tray use - Google Patents

Abstract

The present invention relates to field of iron and steel smelting, specifically chrome ferritic high temperature steel making method in a kind of boiler swing pipe tray use, its weight percent chemical composition is: C:0.05-0.12%, Si:0.60-1.50%, Mn:0.30-1.0%, Cr:16.0-20.0%, Ni:0.02-0.10%, Al:0.60-1.20%, N:0-0.015%, all the other are iron and inevitable impurity.The manufacture method of this jessop; comprise; electric furnace+VOD+LF smelts; through continuous casting → hot rolling → normalizing furnace annealing; wherein, continuous blank heating temperature controls between 1100-1150 DEG C, and the temperature of hot-rolled sheet annealing controls between 780 DEG C-860 DEG C; annealing time is at 2-3min/mm, and the type of cooling adopts air cooling.The steel plate tensile strength obtained is 500-650MPa, and yield strength is 300-450MPa, and Brinell hardness is 165-195, and unit elongation is 18-30%.

Description

Chrome ferritic high temperature steel making method in a kind of boiler swing pipe tray use

Technical field

The present invention relates to field of iron and steel smelting, specifically chrome ferritic high temperature steel making method in a kind of boiler swing pipe tray use.

Background technology

In recent years in order to solve the energy shortage and problem of environmental pollution that become increasingly conspicuous, high efficiency super (super-) critical unit becomes the main force of thermal power generation gradually.At present, power plant mainly promotes thermo-efficiency by improving vapor temperature, and the use properties of raising to generating set boiler steel of vapor temperature is had higher requirement.

Boi1er tube mainly T91 and T92 of ferrite series, and in order to ensure the consistence of hot thermal expansivity, the swing pipe tray matched with ferrite series boi1er tube also must be ferritic steel.Current tray steel mainly uses 1Cr6Si2Mo, but along with the upgrading of boiler technology, the raising of vapor temperature, the heat resisting temperature of 1Cr6Si2Mo is limited, can not satisfy the demand.

Summary of the invention

Technical problem to be solved by this invention is: chrome ferritic high temperature steel making method in the boiler swing pipe tray use how providing a kind of heat resisting temperature high.

The present invention says that the technical scheme of employing is: chrome ferritic high temperature steel making method in a kind of boiler swing pipe tray use, carries out in accordance with the following steps:

Step one, in smelting furnace, adjust molten steel composition, steel quality per-cent is made to meet C:0.05-0.12%, Si:0.60-1.50%, Mn:0.30-1.0%, Cr:16.0-20.0%, Ni:0.02-0.10%, Al:0.60-1.20%, N:0-0.015%, Mn and Al mass percent sum is 1.0-2.0%, and all the other are iron and inevitable impurity;

Step 2, obtain after continuous casting → hot rolling → normalizing furnace annealing, continuous blank heating temperature controls between 1100-1150 DEG C, and the temperature of annealing controls between 780 DEG C-860 DEG C, and annealing time is at 2-3min/mm, and the type of cooling adopts air cooling.

The invention has the beneficial effects as follows: in the boiler swing pipe tray use that the present invention makes, chrome ferritic high temperature steel is not only heat-resisting, and there is excellent mechanical property, being embodied in tensile strength is 500-650MPa, yield strength is 300-450MPa, Brinell hardness is 165-195, and unit elongation is 18-30%.

Embodiment

Embodiment 1

Carry out electric furnace+VOD+LF according to the composition of embodiment in table 11 to smelt, obtain this enforcement steel through continuous casting → hot rolling → normalizing furnace annealing, final steel plate thickness is 6mm.Wherein continuous blank heating temperature controls between 1100-1120 DEG C, and the temperature of hot-rolled sheet annealing controls between 840 DEG C-850 DEG C, and annealing time is 18min, and the type of cooling adopts air cooling.Its performance is in table 2.

Embodiment 2

Carry out electric furnace+VOD+LF according to the composition of embodiment in table 12 to smelt, obtain this enforcement steel through continuous casting → hot rolling → normalizing furnace annealing, final steel plate thickness is 8mm.Wherein continuous blank heating temperature controls between 1100-1120 DEG C, and the temperature of hot-rolled sheet annealing controls between 800 DEG C-810 DEG C, and annealing time is 24min, and the type of cooling adopts air cooling.Its performance is in table 2.

Embodiment 3

Carry out electric furnace+VOD+LF according to the composition of embodiment in table 13 to smelt, obtain this enforcement steel through continuous casting → hot rolling → normalizing furnace annealing, final steel plate thickness is 5mm.Wherein continuous blank heating temperature controls between 1130-1150 DEG C, and the temperature of hot-rolled sheet annealing controls between 850 DEG C-860 DEG C, and annealing time is 15min, and the type of cooling adopts air cooling.Its performance is in table 2.

Embodiment 4

Carry out electric furnace+VOD+LF according to the composition of embodiment in table 14 to smelt, obtain this enforcement steel through continuous casting → hot rolling → normalizing furnace annealing, final steel plate thickness is 8mm.Wherein continuous blank heating temperature controls between 1130-1150 DEG C, and the temperature of hot-rolled sheet annealing controls between 780 DEG C-790 DEG C, and annealing time is 24min, and the type of cooling adopts air cooling.Its performance is in table 2.

Embodiment 5

Carry out electric furnace+VOD+LF according to the composition of embodiment in table 15 to smelt, obtain this enforcement steel through continuous casting → hot rolling → normalizing furnace annealing, final steel plate thickness is 6mm.Wherein continuous blank heating temperature controls between 1120-1140 DEG C, and the temperature of hot-rolled sheet annealing controls between 830 DEG C-840 DEG C, and annealing time is 18min, and the type of cooling adopts air cooling.Its performance is in table 2.

Embodiment 6

Carry out electric furnace+VOD+LF according to the composition of embodiment in table 16 to smelt, obtain this enforcement steel through continuous casting → hot rolling → normalizing furnace annealing, final steel plate thickness is 8mm.Wherein continuous blank heating temperature controls between 1120-1140 DEG C, and the temperature of hot-rolled sheet annealing controls between 810 DEG C-820 DEG C, and annealing time is 24min, and the type of cooling adopts air cooling.Its performance is in table 2.

Table 1

Table 2

As can be seen from the above results, in mentioned component and process program development, chrome ferritic high temperature steel has excellent mechanical property, and being embodied in tensile strength is 500-650MPa, and yield strength is 300-450MPa, Brinell hardness is 165-195, and unit elongation is 18-30%.

Claims (1)

1. a chrome ferritic high temperature steel making method in boiler swing pipe tray use, is characterized in that carrying out in accordance with the following steps:

Step one, in smelting furnace, adjust molten steel composition, steel quality per-cent is made to meet C:0.05-0.12%, Si:0.60-1.50%, Mn:0.30-1.0%, Cr:16.0-20.0%, Ni:0.02-0.10%, Al:0.60-1.20%, N:0-0.015%, Mn and Al mass percent sum is 1.0-2.0%, and all the other are iron and inevitable impurity;

Step 2, obtain after continuous casting → hot rolling → normalizing furnace annealing, continuous blank heating temperature controls between 1100-1150 DEG C, and the temperature of annealing controls between 780 DEG C-860 DEG C, and annealing time is at 2-3min/mm, and the type of cooling adopts air cooling.