A Fe ALLOY

Description

TECHNICAL FIELD

[0001] The present invention relates to a ferroalloy, and more specifically to a ferroalloy material which is sparkless under impaction and friction and explosion proof.

BACKGROUND

[0002] No-spark metal materials in the prior art are mainly copper alloys. However, apparatus and tools made of no-spark copper alloys tend to exhibit inferior hardness, resulting in dramatically shortened service life and high operating costs, which has impeded the development of the industry for a long time.

[0003] A ferroalloy is disclosed in Chinese Patent Application No. 85103868, which is composed of 2.00-3.25wt% of C, 0.40-1.2wt% of Mn, 0.40-0.90wt% of Si, 0.70-1.50wt% of Cr, 0.60-1.2wt% of B, 0.05wt% or less of P, 0.05wt% or less of S and the balance being Fe to sum up to 100wt%, in which the contents of P and S are kept as low as possible.

[0004] A hard and wear resistant ferroalloy is disclosed in Chinese Patent Application No. 86102537, which is composed of 2.50-3.00wt% of C, 0.50-1.30wt% of Mn, 0.30-1.3wt% of Si, 25.0-30.0wt% of Cr, 3.90-4.75wt% of Ni, 2.0-2.5wt% of Mo, 0.05wt% or less of P, 0.05wt% or less of S, 0.4-1.0wt% of V, 3.0-4.0wt% of B and the balance being Fe to sum up to 100%.

[0005] Both of the ferroalloys mentioned in the above two patent application documents have superior hardness and a wear resistance, but they tend to produce sparks during the incidents of impaction and friction, rendering them unsuitable for application in the explosion proof and sparkless field.

SUMMARY OF THE INVENTION

[0006] An object of the present invention is to provides a ferroalloy being both sparkless under impaction and friction and explosion proof, which meets the criterions hold by the manufacturers of emergency rescue apparatus used for the case of leakage of dangerous chemicals from metal containers and manufacturers of metal containers for dangerous chemicals and is suitable for the application in the no-spark and explosion proof field.

[0007] In order to achieve the above-said object, the present invention provides a ferroalloy which is composed of 0.01-0.26wt% of C, 0.08-1.00wt% of Si, 4.50-12.00wt% of Mn, 0.02-0.2wt% of P, 0.02-0.06wt% of S, 3.50-22.00wt% ofNi, 15.00-24.00wt% of Cr and the balance of Fe, based on the weight of said ferroalloy.

[0008] In an embodiment of the present invention, the ferroalloy is composed of 0.15-0.18wt% of C, 0.085-0.09wt% of Si, 5.00-8.00wt% of Mn, 0.03-0.05wt% of P, 0.02-0.025wt% of S, 17.00-19.00wt% ofNi, 16.00-18.00wt% of Cr and the balance of Fe, based on the weight of said ferroalloy.

[0009] In an embodiment of the present invention, the ferroalloy is composed of 0.18wt% of C, 0.09wt% of Si, 8.00wt% of Mn, 0.05wt% of P, 0.02wt% of S, 19.00wt% of Ni, 18.00wt% of Cr and the balance of Fe, based on the weight of said ferroalloy; or
the ferroalloy is composed of 0.15wt% of C, 0.085wt% of Si, 5.00wt% of Mn, 0.03wt% of P, 0.025wt% of S, 17.00wt% ofNi, 16.00wt% of Cr and the balance of Fe, based on the weight of said ferroalloy.

[0010] In an embodiment of the present invention, the ferroalloy further comprises 0.05-6.00wt% of Mo.

[0011] In an embodiment of the present invention, the ferroalloy is composed of 0.020-0.08wt% of C, 0.09-1.00wt% of Si, 9.00-11.00wt% of Mn, 0.08-0.15wt% of P, 0.035-0.045wt% of S, 9.50-21.00wt% of Ni, 19.00-22.00wt% of Cr, 0.06-0.10wt% of Mo and the balance of Fe, based on the weight of said ferroalloy.

[0012] In an embodiment of the present invention, the ferroalloy is composed of
0.04wt% of C, 1.00wt% of Si, 11.00wt% of Mn, 0.10wt% of P, 0.035wt% of S, 12.00wt% of Ni, 22.00wt% of Cr, 0.06wt% of Mo and the balance of Fe, based on the weight of said ferroalloy; or
0.020wt% of C, 0.09wt% of Si, 10.00wt% of Mn, 0.08wt% of P, 0.035wt% of S, 21.00wt% of Ni, 22.00wt% of Cr, 0.10wt% of Mo and the balance of Fe, based on the weight of said ferroalloy.

[0013] In an embodiment of the present invention, the ferroalloy is composed of 0.08wt% of C, 0.095wt% of Si, 9.00wt% of Mn, 0.15wt% of P, 0.045wt% of S, 9.50wt% of Ni, 19.00wt% of Cr, 0.09wt% of Mo and the balance of Fe, based on the weight of said ferroalloy.

[0014] In an embodiment of the present invention, the ferroalloy further comprises 0.01-4.00wt% of Cu, 0.01-0.22wt% ofN and the balance of Fe.

[0015] In an embodiment of the present invention, the ferroalloy is composed of 0.012-0.017wt% of C, 0.08-0.085wt% of Si, 7.50-12.00wt% of Mn, 0.02wt% of P, 0.025wt% of S, 15.00-20.00wt% of Ni, 17.00-22.00wt% of Cr, 0.05-2.00wt% of Mo, 0.09-0.12wt% of Cu, 0.09-0.12wt% of N and the balance of Fe, based on the weight of said ferroalloy.

[0016] In an embodiment of the present invention, the ferroalloy is composed of
0.012wt% of C, 0.08wt% of Si, 12.00wt% of Mn, 0.02wt% of P, 0.025wt% of S, 20.00wt% of Ni, 22.00wt% of Cr, 0.05wt% of Mo, 0.12wt% of Cu, 0.12wt% of N and the balance of Fe; or
0.017wt% of C, 0.085wt% of Si, 7.50wt% of Mn, 0.02wt% of P, 0.025wt% of S, 15.00wt% of Ni, 17.00wt% of Cr, 2.00wt% of Mo, 0.09wt% of Cu, 0.09wt% of N and the balance of Fe.

[0017] When compared with the prior art ones, the ferroalloy of the present invention is both sparkless under impaction and friction and explosion proof. Said ferroalloy can be used for manufacturing metal containers for dangerous chemicals, thus avoiding occurrence of serious accidents caused by leakage of dangerous chemicals therefrom due to the rupture of the containers under incidental impaction and friction during the transporting and handling. Said ferroalloy can also be used in the manufacture of emergency rescue apparatus which, when used for the incident of leakage of dangerous chemicals, will not bring about any spark even if impaction or friction between the apparatus and the metal containers happens, thus avoiding the risk of deteriorating the serious accidents while securing safety and effectiveness of the emergency rescue. The ferroalloy of the present invention is also suitable for application in the explosion proof and no spark field.

BEST EMBODIMENTS OF THE INVENTION

Example 1:

[0018] Steel raw material containing required components of C, Mn, Si, S and P was mixed with Ni and Cr under required quantities and then heated to melt so as to obtain the following chemical composition, which is determined by sampling and analysis: 0.15wt% of C, 5.0wt% of Mn, 0.085wt% of Si, 0.03wt% of P, 0.025wt% of S, 17.00wt% of Ni, 16.00wt% of Cr and the balance of Fe. The ferroalloy was cast into different sections, which were processed and machined into metal containers for dangerous chemicals and emergency rescue apparatus as well as other tools. Their performances are shown in example 8.

Example 2:

[0019] Steel raw material containing required components of C, Mn, Si, S and P was mixed with Ni and Cr under required quantities and then heated to melt so as to obtain the following chemical composition, which is determined by sampling and analysis: 0.18wt% of C, 8.00wt% of Mn, 0.09wt% of Si, 0.05wt% of P, 0.02wt% of S, 19.0wt% of Ni, 18.00wt% of Cr and the balance of Fe. The ferroalloy was cast into different sections, which were processed and machined into metal containers for dangerous chemicals and emergency rescue apparatus as well as other tools. Their performances are shown in example 8.

Example 3:

[0020] Steel raw material containing required components of C, Mn, Si, S and P was mixed with Ni, Cr and Mo under required quantities and then heated to melt so as to obtain the following chemical composition, which is determined by sampling and analysis: 0.08wt% of C, 10.00wt% of Mn, 0.09wt% of Si, 0.08wt% of P, 0.035wt% of S, 21.00wt% of Ni, 18.00wt% of Cr, 0.10wt% of Mo and the balance of Fe. The ferroalloy was cast into different sections, which were processed and machined into metal containers for dangerous chemicals and emergency rescue apparatus as well as other tools. Their performances are shown in example 8.

Example 4:

[0021] Steel raw material containing required components of C, Mn, Si, S and P was mixed with Ni, Cr and Mo under required quantities and then heated to melt so as to obtain the following chemical composition, which is determined by sampling and analysis: 0.04wt% of C, 11.00wt% of Mn, 1.00wt% of Si, 0.10wt% of P, 0.035wt% of S, 12.00wt% of Ni, 22.00wt% of Cr, 0.06wt% of Mo and the balance of Fe. The ferroalloy was cast into different sections, which were processed and machined into metal containers for dangerous chemicals and emergency rescue apparatus as well as other tools. Their performances are shown in example 8.

Example 5:

[0022] Steel raw material containing required components of C, Mn, Si, S and P was mixed with Ni, Cr and Mo under required quantities and then heated to melt so as to obtain the following chemical composition, which is determined by sampling and analysis: 0.02wt% of C, 9.00wt% of Mn, 0.095wt% of Si, 0.15wt% of P, 0.045wt% of S, 9.50wt% of Ni, 19.00wt% of Cr, 0.09wt% of Mo and the balance of Fe. The ferroalloy was cast into different sections, which were processed and machined into metal containers for dangerous chemicals and emergency rescue apparatus as well as other tools. Their performances are shown in example 8.

Example 6:

[0023] Steel raw material containing required components of C, Mn, Si, S, P, Cu and N was mixed with Ni, Cr and Mo under required quantities and then heated to melt so as to obtain the following chemical composition, which is determined by sampling and analysis: 0.017wt% of C, 7.50wt% of Mn, 0.085wt% of Si, 0.02wt% of P, 0.025wt% of S, 15.00wt% of Ni, 17.00wt% of Cr, 2.00wt% of Mo, 0.09wt% of Cu, 0.09wt% of N and the balance of Fe. The ferroalloy was cast into different sections, which were processed and machined into metal containers for dangerous chemicals and emergency rescue apparatus as well as other tools. Their performances are shown in example 8.

Example 7:

[0024] Steel raw material containing required components of C, Mn, Si, S, P, Cu and N was mixed with Ni, Cr and Mo under required quantities and then heated to melt so as to obtain the following chemical composition, which is determined by sampling and analysis: 0.012wt% of C, 12.00wt% of Mn, 0.08wt% of Si, 0.02wt% of P, 0.025wt% of S, 20.00wt% of Ni, 22.00wt% of Cr, 0.05wt% of Pt, 0.12wt% of Cu , 0.12wt% of N and the balance of Fe. The ferroalloy was cast into different sections, which were processed and machined into metal containers for dangerous chemicals and emergency rescue apparatus as well as other tools. Their performances are shown in example 8.

Example 8:

(A) Samples were made of alloys of examples 1-7 and their explosion proof properties were measured.

[0025] Testing Method
Explosion proof properties were measured according to GB 10686-89, Testing
Method for Explosion Proof Properties of Tools Made of Copper Alloys.

(1) Free Falling Hammer Test

[0026] The free falling hammer tests were conducted according to the standard of GB 10686.

[0027] Test Temperature: 16 °C; Humidity: 40% RH(relative humidity); Atmospheric Pressure: 100kPa
Sample Gauge: 60(diameter) × 30mm
Number of Samples: three blocks
Mass of Hammer: 14 kg
Testing Gas: a mixture of methane and air
Concentration of Testing Gas: 6.0-7.0 %
Distance from Hammer to Falling Point: 4m
Angle between the Steel Sheet to be impacted and the Horizontal Plane: 45 degree.

[0028] Process of Test: the falling and impacting tests are performed by using a 14kg hammer from a height of 4m for 32 times.

[0029] Standard of Test: No explosion in all of the 32 falling and impacting tests was taken as being qualified.

(2) Rotational Friction Test

[0030] The rotational friction tests were conducted according to the standard of GB 10686.

[0031] Test Temperature: 16 °C ; Humidity: 40% RH(relative humidity); and Atmospheric Pressure: 100kPa
Sample Gauge: 10(diameter) × 150mm
Number of Samples: six bars
Rotational Speed of Revolving Tray: 3000 r/min
Testing Gas: a mixture of methane and air
Concentration of Testing Gas: 6.0-7.0 %
Pressing Force used in the Test: 490 N
Times of Test per min.: five
Process of Test: 5 times of friction tests were conducted for each sample, and no explosion for all of 30 times of rotational friction tests was taken as being qualified.
The tested results are shown in Table 1:

Table 1: Results of Explosion Proof Property Tests for the samples of Examples 1-7

Sample	Results for Free Falling Hammer Tests	Results for Rotational Friction Tests
Example 1:	Qualified	Qualified
Example 2:	Qualified	Qualified
Example 3:	Qualified	Qualified
Example 4:	Qualified	Qualified
Example 5:	Qualified	Qualified
Example 6:	Qualified	Qualified
Example 7:	Qualified	Qualified

(B) Samples were made of alloys of examples 1 and 5 and their physical properties were measured.

Testing Method

[0032] Tensile strength and yield strength (RP_0.2) were measured according to the standard of GB/T228-2002.
Hardness Test: measured according to GB/T230.1-2004.
Testing Environment: room temperature
Testing Equipments: Double Rockwell Hardness Meter, Type T2001, INSTRON Inc. and Universal Material Testing Machine, Type SHT4106D, New Sansi Material Testing Ltd., Shenzhen

The results are shown in Table 2:

Sample	Tensile Strength/Mpa	Yield Strength/Mpa	Tensile Elongation/%	Hardness (HRB)
Example 1:	270	250	4.5	83.0
Example 5:	430	245	19.5	80.0

Claims

1. A ferroalloy which is composed of 0.01-0.26wt% of C, 0.08-1.00wt% of Si, 4.50-12.00wt% of Mn, 0.02-0.2wt% of P, 0.02-0.06wt% of S, 3.50-22.00wt% ofNi, 15.00-24.00wt% of Cr and the balance of Fe, based on the weight of said ferroalloy.

2. The ferroalloy according to claim 1, wherein it is composed of 0.15-0.18wt% of C, 0.085-0.09wt% of Si, 5.00-8.00wt% of Mn, 0.03-0.05wt% of P, 0.02-0.025wt% of S, 17.00-19.00wt% ofNi, 16.00-18.00wt% of Cr and the balance of Fe, based on the weight of said ferroalloy.

3. The ferroalloy according to claim 1, wherein
it is composed of 0.18wt% of C, 0.09wt% of Si, 8.00wt% of Mn, 0.05wt% of P, 0.02wt% of S, 19.00wt% of Ni, 18.00wt% of Cr and the balance of Fe, based on the weight of said ferroalloy; or
it is composed of 0.15wt% of C, 0.085wt% of Si, 5.00wt% of Mn, 0.03wt% of P, 0.025wt% of S, 17.00wt% of Ni, 16.00wt% of Cr and the balance of Fe, based on the weight of said ferroalloy.

4. The ferroalloy according to claim 1, wherein it further comprises 0.05-6.00wt% of Mo, based on the weight of said ferroalloy.

5. The ferroalloy according to claim 4, wherein it is composed of 0.020-0.08wt% of C, 0.09-1.00wt% of Si, 9.00-11.00wt% of Mn, 0.08-0.15wt% of P, 0.035-0.045wt% of S, 9.50-21.00wt% of Ni, 19.00-22.00wt% of Cr, 0.06-0.10wt% of Mo and the balance of Fe, based on the weight of said ferroalloy.

6. The ferroalloy according to claim 4, wherein it is composed of
0.04wt% of C, 1.00wt% of Si, 11.00wt% of Mn, 0.10wt% of P, 0.035wt% of S, 12.00wt% of Ni, 22.00wt% of Cr, 0.06wt% of Mo and the balance of Fe, based on the weight of said ferroalloy; or
0.020wt% of C, 0.09wt% of Si, 10.00wt% of Mn, 0.08wt% of P, 0.035wt% of S, 21.00wt% of Ni, 22.00wt% of Cr, 0.10wt% of Mo and the balance of Fe, based on the weight of said ferroalloy.

7. The ferroalloy according to claim 4, wherein it is composed of 0.08wt% of C, 0.095wt% of Si, 9.00wt% of Mn, 0.15wt% of P, 0.045wt% of S, 9.50wt% of Ni, 19.00wt% of Cr, 0.09wt% of Mo and the balance of Fe, based on the weight of said ferroalloy.

8. The ferroalloy according to claim 4, wherein it further comprises 0.01-4.00wt% of Cu, 0.01-0.22wt% of N and the balance of Fe, based on the weight of said ferroalloy.

9. The ferroalloy according to claim 8, wherein it is composed of 0.012-0.017wt% of C, 0.08-0.085wt% of Si, 7.50-12.00wt% of Mn, 0.02wt% of P, 0.025wt% of S, 15.00-20.00wt% of Ni, 17.00-22.00wt% of Cr, 0.05-2.00wt% of Mo, 0.09-0.12wt% of Cu, 0.09-0.12wt% of N and the balance of Fe, based on the weight of said ferroalloy.

10. The ferroalloy according to claim 8, wherein it is composed of
0.012wt% of C, 0.08wt% of Si, 12.00wt% of Mn, 0.02wt% of P, 0.025wt% of S, 20.00wt% of Ni, 22.00wt% of Cr, 0.05wt% of Mo, 0.12wt% of Cu, 0.12wt% of N and the balance of Fe, based on the weight of said ferroalloy; or
0.017wt% of C, 0.085wt% of Si, 7.50wt% of Mn, 0.02wt% of P, 0.025wt% of S, 15.00wt% of Ni, 17.00wt% of Cr, 2.00wt% of Mo, 0.09wt% of Cu, 0.09wt% of N and the balance of Fe, based on the weight of said ferroalloy.