Method for producing a stainless steel diffusion-bonded product

• US 9,987,706 B2
• Filed: 05/15/2013
• Issued: 06/05/2018
• Est. Priority Date: 05/15/2013
• Status: Active Grant

• Current Assignee: Nippon Steel Stainless Steel Corporation (Nippon Steel Corporation)
• Original Assignee: Nisshin Steel Company Limited (Nippon Steel Corporation)
• Inventors: Sugama, Atsushi, Nishida, Yukihiro, Kageoka, Kazuyuki, Hori, Yoshiaki, Oku, Manabu
• Primary Examiner(s): Patel, Devang R
• Application Number:
  US14/888,975
• Publication Number:
  US 20160114423A1
• Time in Patent Office: 1,847 Days
• Field of Search: 228193
• CPC Class Codes: B23K 20/00 Non-electric welding by applying impact or other pressure, with or without the application of heat, e.g. cladding or plating
• CPC Class Codes: B23K 20/02 by means of a press ; Diffusion bonding B23K20/001, B23K20/04 take precedence
• CPC Class Codes: B23K 20/023 Thermo-compression bonding
• CPC Class Codes: B23K 20/227 with ferrous layer
• CPC Class Codes: B23K 2103/05 Stainless steel
• CPC Class Codes: B23K 35/308 with Cr as next major constituent
• CPC Class Codes: B23K 35/3086 containing Ni or Mn
• CPC Class Codes: C21D 6/002 containing Cr C21D6/004 takes precedence
• CPC Class Codes: C21D 9/50 for welded joints
• CPC Class Codes: C22C 38/00 Ferrous alloys, e.g. steel alloys cast-iron alloys C22C37/00
• CPC Class Codes: C22C 38/001 containing N
• CPC Class Codes: C22C 38/02 containing silicon
• CPC Class Codes: C22C 38/04 containing manganese
• CPC Class Codes: C22C 38/06 containing aluminium
• CPC Class Codes: C22C 38/42 with copper
• CPC Class Codes: C22C 38/44 with molybdenum or tungsten
• CPC Class Codes: C22C 38/46 with vanadium
• CPC Class Codes: C22C 38/48 with niobium or tantalum
• CPC Class Codes: C22C 38/50 with titanium or zirconium
• CPC Class Codes: C22C 38/54 with boron

Abstract

A method for producing a stainless steel diffusion-bonded product provides a stainless steel material diffusion-bonded product having excellent reliability of the bonded portion by using a direct method, which includes directly contacting stainless steel materials with each other to unify the materials together by diffusion bonding. At least one of the stainless steel materials to be contacted is dual-phase steel having an austenite transformation starting temperature Ac₁ point of 650 to 950° C. during the temperature elevation and having an austenite+ferrite dual-phase temperature region in the range of 880° C. or higher. Diffusion bonding is advanced under conditions such that the contact surface pressure is in the range of 1.0 MPa or less and the heating temperature is in the range of from 880 to 1,080° C. while being accompanied by the movement of grain boundary caused when the ferrite phase in the dual-phase steel undergoes transformation to an austenite phase.

Claims

1. A method for producing a stainless steel diffusion-bonded product, comprising:

providing a dual phase steel having an austenite transformation starting temperature Ac₁ point of 650 to 950°

C. during the temperature elevation and having an austenite+ferrite dual-phase temperature region in the range of 880°

C. or higher and another stainless steel; and

diffusion bonding the at least one dual phase steel to the other stainless steel to unify the materials together by direct contact without using any insert material, the diffusion bonding being advanced under conditions such that the contact surface pressure is in the range of 1.0 MPa or less and the heating temperature is in the range of from 880 to 1,080°

C. while being accompanied by the movement of grain boundary caused when the ferrite phase in the dual-phase steel undergoes transformation to an austenite phase.

2. A method for producing a stainless steel diffusion-bonded product, comprising:

providing a dual phase steel having a dual-phase temperature region in the range of 880°

C. or higher and another stainless steel, the providing step further comprising providing the dual phase steel with a chemical composition (A) comprising from 0.0001 to 0.15% of C, from 0.001 to 1.0% of Si, from 0.001 to 1.0% of Mn, from 0.05 to 2.5% of Ni, from 13.0 to 18.5% of Cr, from 0 to 0.2% of Cu, from 0 to 0.5% of Mo, from 0 to 0.05% of Al, from 0 to 0.2% of Ti, from 0 to 0.2% of Nb, from 0 to 0.2% of V, from 0 to 0.01% of B, and from 0.005 to 0.1% of N, all in terms of percentage by mass, with the balance of Fe and unavoidable impurities and having the composition satisfy a formula (1) where X is 650 to 950 and X is defined by the formula (1) wherein

X value=35(Cr+1.72Mo+2.09Si+4.86Nb+8.29V+1.77Ti+21.4Al+40.0B−

7.14C−

8.0N−

3.28Ni−

1.89Mn−

0.51Cu)+310 

 

(1); and

diffusion bonding the at least one dual phase steel to the other stainless steel to unify the materials together by direct contact without using any insert material, the diffusion bonding being advanced under conditions such that the contact surface pressure is in the range of 1.0 MPa or less and the heating temperature is in the range of from 880 to 1,080°

C. while being accompanied by the movement of grain boundary caused when the ferrite phase in the dual-phase steel undergoes transformation to an austenite phase.

5. The method for producing a stainless steel diffusion-bonded product according to claim 2, wherein the dual-phase steel having the chemical composition (A) is a steel having a γ

max represented by the formula (2) below of 20 to less than 100;

γ

max=420C−

11.5Si+7Mn+23Ni−

11.5Cr−

12Mo+9Cu−

49Ti−

50Nb−

52Al+470N+189 

 

(2).

6. The method for producing a stainless steel diffusion-bonded product according to claim 2, wherein the dual-phase steel having the chemical composition (A) is a steel having a γ

max represented by the formula (2) below of 20 to less than 100, and the diffusion bonding is advanced under conditions such that the contact surface pressure is in the range of from 0.03 to 0.8 MPa and the heating temperature is in the range of from 880 to 1,030°

C. while being accompanied by the movement of grain boundary caused when the ferrite phase in the dual-phase steel undergoes transformation to an austenite phase;

γ

max=420C−

11.5Si+7Mn+23Ni−

11.5Cr−

12Mo+9Cu−

49Ti−

50Nb−

52Al+470N+189 

 

(2).

3. A method for producing a stainless steel diffusion-bonded product, comprising:

providing a dual phase steel having a dual-phase temperature region in the range of 880°

C. or higher and another stainless steel, the providing step further comprising providing the dual phase steel with a chemical composition (A) comprising from 0.0001 to 0.15% of C, from 0.001 to 1.0% of Si, from 0.001 to 1.0% of Mn, from 0.05 to 2.5% of Ni, from 13.0 to 18.5% of Cr, from 0 to 0.2% of Cu, from 0 to 0.5% of Mo, from 0 to 0.05% of Al, from 0 to 0.2% of Ti, from 0 to 0.2% of Nb, from 0 to 0.2% of V, from 0 to 0.01% of B, and from 0.005 to 0.1% of N, all in terms of percentage by mass, with the balance of Fe and unavoidable impurities and having the composition satisfy a formula (1) where X is 650 to 950 and X is defined by the formula (1) wherein

X value=35(Cr+1.72Mo+2.09Si+4.86Nb+8.29V+1.77Ti+21.4Al+40.0B−

7.14C−

8.0N−

3.28Ni−

1.89Mn−

0.51Cu)+310 

 

(1);

and providing the other stainless steel with a chemical composition (B) comprising from 0.0001 to 0.15% of C, from 0.001 to 4.0% of Si, from 0.001 to 2.5% of Mn, from 0.001 to 0.045% of P, from 0.0005 to 0.03% of S, from 6.0 to 28.0% of Ni, from 15.0 to 26.0% of Cr, from 0 to 7.0% of Mo, from 0 to 3.5% of Cu, from 0 to 1.0% of Nb, from 0 to 1.0% of Ti, from 0 to 0.1% of Al, from 0 to 0.3% of N, from 0 to 0.01% of B, from 0 to 0.5% of V, from 0 to 0.3% of W, and from 0 to 0.1% of the total of Ca, Mg, Y, and REM (rare earth elements), all in terms of percentage by mass, with the balance of Fe and unavoidable impurities; and

diffusion bonding the dual phase steel and the other stainless steel with each other to unify the materials together by direct contact without using any insert material, the diffusion bonding being advanced under conditions such that the contact surface pressure is in the range of 1.0 MPa or less and the heating temperature is in the range of from 880 to 1,080°

C. while being accompanied by the movement of grain boundary caused when the ferrite phase in the dual-phase steel undergoes transformation to an austenite phase.

7. The method for producing a stainless steel diffusion-bonded product according to claim 3, wherein the dual-phase steel having the chemical composition (A) is a steel having a γ

max represented by the formula (2) below of 20 to less than 100;

γ

max=420C−

11.5Si+7Mn+23Ni−

11.5Cr−

12Mo+9Cu−

49Ti−

50Nb−

52Al+470N+189 

 

(2).

8. The method for producing a stainless steel diffusion-bonded product according to claim 3, wherein the dual-phase steel having the chemical composition (A) is a steel having a γ

max represented by the formula (2) below of 20 to less than 100, and the diffusion bonding is advanced under conditions such that the contact surface pressure is in the range of from 0.03 to 0.8 MPa and the heating temperature is in the range of from 880 to 1,030°

C. while being accompanied by the movement of grain boundary caused when the ferrite phase in the dual-phase steel undergoes transformation to an austenite phase;

γ

max=420C−

11.5Si+7Mn+23Ni−

11.5Cr−

12Mo+9Cu−

49Ti−

50Nb−

52Al+470N+189 

 

(2).

4. A method for producing a stainless steel diffusion-bonded product, comprising:

providing a dual phase steel having a dual-phase temperature region in the range of 880°

C. or higher and another stainless steel, the providing step further comprising providing the dual phase steel with a chemical composition (A) comprising from 0.0001 to 0.15% of C, from 0.001 to 1.0% of Si, from 0.001 to 1.0% of Mn, from 0.05 to 2.5% of Ni, from 13.0 to 18.5% of Cr, from 0 to 0.2% of Cu, from 0 to 0.5% of Mo, from 0 to 0.05% of Al, from 0 to 0.2% of Ti, from 0 to 0.2% of Nb, from 0 to 0.2% of V, from 0 to 0.01% of B, and from 0.005 to 0.1% of N, all in terms of percentage by mass, with the balance of Fe and unavoidable impurities, and having the composition satisfy a formula (1) where X is 650 to 950 and X is defined by the formula (1) wherein

X value=35(Cr+1.72Mo+2.09Si+4.86Nb+8.29V+1.77Ti+21.4Al+40.0B−

7.14C−

8.0N−

3.28Ni−

1.89Mn−

0.51Cu)+310 

 

(1),

and providing the other stainless steel with a chemical composition (C) comprising from 0.0001 to 0.15% of C, from 0.001 to 1.2% of Si, from 0.001 to 1.2% of Mn, from 0.001 to 0.04% of P, from 0.0005 to 0.03% of S, from 0 to 0.6% of Ni, from 11.5 to 32.0% of Cr, from 0 to 2.5% of Mo, from 0 to 1.0% of Cu, from 0 to 1.0% of Nb, from 0 to 1.0% of Ti, from 0 to 0.2% of Al, from 0 to 0.025% of N, from 0 to 0.01% of B, from 0 to 0.5% of V, from 0 to 0.3% of W, and from 0 to 0.1% of the total of Ca, Mg, Y, and REM (rare earth elements), all in terms of percentage by mass, with the balance of Fe and unavoidable impurities; and

diffusion bonding the dual phase steel to the other stainless steel to unify the materials together by direct contact without using any insert material, the diffusion bonding being advanced under conditions such that the contact surface pressure is in the range of 1.0 MPa or less and the heating temperature is in the range of from 880 to 1,080°

C. while being accompanied by the movement of grain boundary caused when the ferrite phase in the dual-phase steel undergoes transformation to an austenite phase.

9. The method for producing a stainless steel diffusion-bonded product according to claim 4, wherein the dual-phase steel having the chemical composition (A) is a steel having a γ

max represented by the formula (2) below of 20 to less than 100;

γ

max=420C−

11.5Si+7Mn+23Ni−

11.5Cr−

12Mo+9Cu−

49Ti−

50Nb−

52Al+470N+189 

 

(2).

10. The method for producing a stainless steel diffusion-bonded product according to claim 4, wherein the dual-phase steel having the chemical composition (A) is a steel having a γ

max represented by the formula (2) below of 20 to less than 100, and the diffusion bonding is advanced under conditions such that the contact surface pressure is in the range of from 0.03 to 0.8 MPa and the heating temperature is in the range of from 880 to 1,030°

C. while being accompanied by the movement of grain boundary caused when the ferrite phase in the dual-phase steel undergoes transformation to an austenite phase;

γ

max=420C−

11.5Si+7Mn+23Ni−

11.5Cr−

12Mo+9Cu−

49Ti−

50Nb−

52Al+470N+189 

 

(2).